Components of medicinal leech saliva

Hirudin = Inhibits blood coagulation by binding to thrombin

Calin = inhibits blood coagulation by blocking the binding of von Willebrand factor to collagen. Inhibits collagen- mediated platelet aggregation

Destabilase = Monomerizing activity. Dissolves fibrin. Thrombolytic effects

Hirustasin = Inhibits kallikrein, trypsin, chymotrypsin, neutropholic cathepsin G

Bdellins = Anti-inflammatory. Inhibits trypsin, plasmin, acrosin

Hyaluronidase = Increases interstitial viscosity. Antibiotic

Tryptase inhibitor =Inhibits proteolytic enzymes of host mast cells

Eglins = Anti-inflammatory = Inhibit the activity of alpha-chymotrypsin, chymase, substilisin, elastase, cathepsin G

Types of Fish Diseases

There are two broad categories of disease that affect fish, infectious and non-infectious diseases. Infectious diseases are caused by pathogenic organisms present in the environment or carried by other fish. They are contagious diseases, and some type of treatment may be necessary to control the disease outbreak. In contrast, non-infectious diseases are caused by environmental problems, nutritional deficiencies, or genetic anomalies; they are not contagious and usually cannot be cured by medications.
Infectious diseases. Infectious diseases are broadly categorized as parasitic, bacterial, viral, or fungal diseases.

Parasitic diseases of fish are most frequently caused by small microscopic organisms called protozoa which live in the aquatic environment. There are a variety of protozoans which infest the gills and skin of fish causing irritation, weight loss, and eventually death. Most protozoan infections are relatively easy to control using standard fishery chemicals such as copper sulfate, formalin, or potassium permanganate. Information on specific diseases and proper use of fishery chemicals is available from your aquaculture extension specialist.

Bacterial diseases are often internal infections and require treatment with medicated feeds containing antibiotics which are approved for use in fish by the Food and Drug Administration. Typically fish infected with a bacterial disease will have hemorrhagic spots or ulcers along the body wall and around the eyes and mouth. They may also have an enlarged, fluid-filled abdomen, and protruding eyes. Bacterial diseases can also be external, resulting in erosion of skin and ulceration. Columnaris is an example of an external bacterial infection which may be caused by rough handling.

Viral diseases are impossible to distinguish from bacterial diseases without special laboratory tests. They are difficult to diagnose and there are no specific medications available to cure viral infections of fish. The most important viral infection which affects fish production in the southeastern United States is Channel Catfish Virus Disease, caused by a herpes virus. Consultation with an aquaculture or fish health specialist is recommended if you suspect a bacterial or viral disease is killing your fish.

Fungal diseases are the fourth type of infectious disease. Fungal spores are common in the aquatic environment, but do not usually cause disease in healthy fish. When fish are infected with an external parasite, bacterial infection, or injured by handling, the fungi can colonize damaged tissue on the exterior of the fish. These areas appear to have a cottony growth or may appear as brown matted areas when the fish are removed from the water. Formalin or potassium permanganate are effective against most fungal infections. Since fungi are usually a secondary problem it is important to diagnose the original problem and correct it as well.

Non-infectious diseases. Non-infectious diseases can be broadly categorized as environmental, nutritional, or genetic.

Environmental diseases are the most important in commercial aquaculture. Environmental diseases include low dissolved oxygen, high ammonia, high nitrite or natural or man-made toxins in the aquatic environment. Proper techniques of managing water quality will enable producers to prevent most environmental diseases. There are separate IFAS publications which address water quality management in greater detail.

Nutritional diseases can be very difficult to diagnose. A classic example of a nutritional disease of catfish is "broken back disease," caused by vitamin C deficiency. The lack of dietary vitamin C contributes to improper bone development, resulting in deformation of the spinal column. Another important nutritional disease of catfish is "no blood disease" which may be related to a folic acid deficiency. Affected fish become anemic and may die. The condition seems to disappear when the deficient feed is discarded and a new feed provided. Additional information on nutrition of fish is available through your aquaculture veterinary extension specialist.

Genetic abnormalities include conformational oddities such as lack of a tail or presence of an extra tail. Most of these are of minimal significance; however, it is important to bring in unrelated fish for use as broodstock every few years to minimize inbreeding.

What to Do if Your Fish are Sick

If you suspect that fish are getting sick, the first thing to do is check the water quality. If you do not have a water quality test kit, contact your county extension office; some counties have been issued these kits, and your extension agent may be able to help you. If your county is not equipped with a water quality test kit, call the aquaculture extension specialist nearest to you (see the list at the end of this publication). Anyone contemplating commercial production of fish should invest in a water quality test kit and learn how to use it. An entry level kit for freshwater aquaculture can be purchased for about $200, and can save thousands of dollars worth of fish with its first use.
Low oxygen is a frequent cause of fish mortality in ponds, especially in the summer. High levels of ammonia are also commonly associated with disease outbreaks when fish are crowded in vats or tanks. Separate extension fact sheets are available that explain oxygen cycles, ammonia cycles, and management of these water quality problems. In general, check dissolved oxygen, ammonia, nitrite, and pH, during a minimum water quality screen associated with a fish disease outbreak. The parameters of significance include total alkalinity, total hardness, nitrate (saltwater systems) and chlorine (if using city water).

Ideally, daily records should be available for immediate reference when a fish disease outbreak occurs. These should include the dates fish were stocked, size of fish at stocking, source of fish, feeding rate, growth rate, daily mortality and water quality. This information is needed by the aquaculture specialist working with you to solve your fish disease problem. Good records, a description of behavioral and physical signs exhibited by sick fish, and results of water quality tests provide a complete case history for the diagnostician working on your case.

Professional assistance is available to Florida residents through the Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences (IFAS) at the University of Florida; the Department of Agriculture and Consumer Services, Division of Animal Industries and Division of Aquaculture, as well as several private laboratories and veterinary practices. A list of public resources is included at the end of this publication.

If you decide to submit fish to a diagnostic laboratory you should collect live, sick fish, place them in a freezer bag (without water), and ship them on ice to the nearest facility. Small fish can be shipped alive by placing them in plastic bags which are partially filled (30%) with water. Oxygen gas can be injected into the bag prior to sealing it. An insulated container is recommended for shipping live, bagged fish as temperature fluctuations during transit are minimized. In addition to fish samples, a water sample collected in a clean jar should also be submitted. Detailed information on submitting samples is available in UF/IFAS Fact Sheet FA-55, Submission of Fish for Diagnostic Evaluation.

Determining if Your Fish are Sick

The most obvious sign of sick fish is the presence of dead or dying animals. However, the careful observer can usually tell that fish are sick before they start dying because sick fish often stop feeding and may appear lethargic. Healthy fish should eat aggressively if fed at regularly scheduled times. Pond fish should not be visible except at feeding time. Fish that are observed hanging listlessly in shallow water, gasping at the surface, or rubbing against objects indicate something may be wrong. These behavioral abnormalities indicate that the fish are not feeling well or that something is irritating them.
In addition to behavioral changes, there are physical signs that should alert producers to potential disease problems in their fish. These include the presence of sores (ulcers or hemorrhages), ragged fins, or abnormal body confirmation (i.e., a distended abdomen or "dropsy" and exopthalmia or "popeye"). When these abnormalities are observed, the fish should be evaluated for parasitic or bacterial infections.

The Significance of Fish Disease to Aquaculture

Fish disease is a substantial source of monetary loss to aquaculturists. Production costs are increased by fish disease outbreaks because of the investment lost in dead fish, cost of treatment, and decreased growth during convalescence. In nature we are less aware of fish disease problems because sick animals are quickly removed from the population by predators. In addition, fish are much less crowded in natural systems than in captivity. Parasites and bacteria may be of minimal significance under natural conditions, but can cause substantial problems when animals are crowded and stressed under culture conditions.
Disease is rarely a simple association between a pathogen and a host fish. Usually other circumstances must be present for active disease to develop in a population. These circumstances are generally grouped under the umbrella term "Stress" .
Stress is discussed in greater detail in the UF/IFAS Extension Circular 919 Stress - Its Role in Fish Disease. Management practices directed at limiting stress are likely to be most effective in preventing disease outbreaks.

When to Terminate a Bath Treatment

No chemical used in aquaculture is completely harmless to fish. Treatments are designed to be more harmful to the problematic organism (ie. bacteria, protozoan) than to the host organism (ie. fish) which results in successful elimination of the pathogen with minimum damage to the fish. For some chemicals, particularly copper sulfate, the difference in chemical concentration which is lethal to the pathogen and that which is lethal to the fish is small. If fish show any signs of distress during the treatment (ie. trying to leave the water, gasping at the surface) the treatment should be terminated immediately and fish placed in clean water.
If fish are in a pond and have been treated with a low concentration of chemical (prolonged bath) there is nothing that can be done to remove the chemical if it has been improperly applied. Again, one way to help avoid losing a pond of fish by accidentally applying too much chemical is to have the amount of chemical to be applied calculated independently by two people. Volumes of ponds should be known and the amount of chemical needed to treat each individual pond should be calculated and recorded for easy reference. Errors are best avoided by preparing for a disease situation before it happens, rather than frantically calculating treatment rates and locating chemical suppliers when a disease is in progress.

How to Add Chemicals to the Bath Treatment

Before applying chemicals double check the chemical you are using, the concentration to be delivered, and ideally, two people should independently calculate the amount of chemical to be added. Proper calculation of concentration is contingent upon accurate determination of volume of water to be treated. If you are uncertain as to the volume of water to be treated take the time to measure the size of the pond or container so that volume can be accurately determined.
Addition of chemicals to water containing fish must be done carefully so that all the chemical is mixed uniformly throughout the water column. If the chemical is not thoroughly mixed, "hot spots" (areas of high concentration of chemical) may be formed which can damage, or kill, fish. To ensure uniform application, dry chemicals can be dissolved in water prior to, or during, application. In some ponds, aerators can be used to help distribute chemicals throughout the water column. Personnel handling chemicals should be encouraged to wear protective clothing.

Sick fish are often weak and may not tolerate chemicals at the concentrations recommended. Never leave fish unattended during treatment. Nets and other equipment used to handle sick fish must be sanitized before being used again.

When to Use Bath Treatments

The aim of most successful bath treatments is to eliminate external infections. External infections occur on the gills, skin, and fins of fish. They can be of parasitic, bacterial or fungal origin. In contrast, use of bath treatments to treat internal infections, particularly systemic bacterial disease, is not generally recommended. Medicated feeds are preferred for treating internal problems. However, if fish are not eating then a bath treatment may be the only method available to administer medication.
The chemicals which are most commonly used for bath treatments are potassium permanganate, formalin, copper sulfate, and salt.

Bath Treatment ...rawatan untuk ikan yang diserang penyakit

Types of Bath Treatments
There are three basic types of bath treatments: dips (less than 1 minute), short-term baths (about 1 hour), and prolonged baths (indefinite). The difference between these bath treatments is the concentration of the chemical applied and the period of time that the fish are in contract with the chemical.

A Dip is just what the name implies. The fish is dipped into a concentrated chemical bath for a short period of time, often less than one minute. Prolonged exposure to the chemical at the high concentration delivered in a dip would be fatal to the fish. Because fatalities can easily result from an improperly administered dip treatment, and because sick fish are generally intolerant of stressful situations, dip treatments are often avoided by many aquarists. An exception to this may be the use of salt water dips when moving fresh water fish, and the use of fresh water dips when moving salt water fish. These techniques are discussed in a separate IFAS Fact Sheet, Use of Salt to Treat Fish Diseases.

A Short-Term Bath means that the fish are subjected to a moderate chemical concentration for a period of time ranging from 30 minutes to several hours. This is an excellent method for administering many medications to fish kept in aquaria, tanks, or raceways. The duration of exposure to the chemical will be determined by the chemical used, the concentration of chemical used, and the facility in which the fish are housed. In most cases, water flow and filtration are shut down while the chemical is in contact with the fish. This prevents rapid dilution of the chemical by in-flowing water and also prevents the chemical from coming in contact with bacteria in the biofilter. If the water flow and circulation is shut down during the treatment, water quality should be monitored to prevent harmful increases in ammonia concentration. Vigorous aeration should always be maintained during treatment.


A Prolonged Bath means that small concentrations of chemical are applied and left in the water on a permanent basis, where it will eventually break down and disappear. This is the only method of administering a bath treatment to pond fish. Because of the low concentrations of chemical applied, a prolonged bath is often the least expensive and safest way of administering a chemical bath. A prolonged bath is not recommended, however, when fish are crowded in a relatively small area such as a tank or vat. Shutting off water flow or filtration for an extended period of time (more than 2-4 hours) under tank conditions is likely to result in serious degradation of water quality which could further stress, or kill directly, the fish.

Fish disease - virus

Infection Pancreatic Necrosis (IPN)
Spring Viraemia of Carp (SVC)
Lymphocystis
Epizootic Haematopoeitic Necrosis (EHN)
Infectious Haematopoietic Necrosis (IHN)
Viral Encephalopathy and Retinopathy ( VER)


Infectious Pancreatic Necrosis

Aetiology: Birnavirus
Characteristics: replicates in cytoplasm
Epizootiology: as it applies to salmonid disease
Reservoir: Carrier fish which secrete virus in the faeces or sexual products
Transmission: eggs, water, direct contacts, piscivors can transport virus
Occurance: any age
Geographic distribution: Japan, Korea, North America, Europe, Taiwan and Chile
Grass carp: Gross signs & pathology: Massive mortalities in grass carp fingerlings, with lower levels of mortality in yearlings, exophthalmia and haemorrhagic areas at the base of the operculum, haemorrhages in the musculature , mouth , intestine , liver and kidney
(Trout): Gross Signs & Patho : whirling about long axis, weak respiration, darkening, exophthalmia , abdominal distention , pancreatic necrosis, multiple petechiae in omental fat, pale liver & spleen, empty gut & white mucus in the intestine
Histopath: characteristic changes in pancreatic acinar cells; necrosis, pyknotic nuclei with a clear halo around them and the surrounding adipose cells wall still be normal
Dx: isolation & presence of typical CPE in cell culture , use RTG-2 cell lines , CPE- stringly lysis; typical histopathology; confirmed with VNT
Ctl: reduce stress, eradication from farm (certified broodstock), disinfect eggs, rear fry in spring water, disinfect tanks and ponds, quarantine

Spring Viraemia Of Carp

Aetoilogy : Rhabdovirus carpio and Aeromonas hydrophila
Characteristics: replicates in cytoplasm
Epizootiology: species affected-cyprinids
Reservoir: carrier fish, latent infections as the virus is only detected in outbreak Transmission: via water, highly infectious
Occurrence: any age affected
Classically seen in the spring as the temperatures rise to greater than 15-20C
Geographic distribution : Europe
Gross signs : darkening, exophthalmia, abdominal distension, lethargy
Then- lie on sides, distended anus, faeces castes trail in water , petechial haemorrhages on gills, skins and fins
Pathology : fibrinous peritonitis, petechial haemorrhages over internal organs , catarhal enteritis, asites
Histopathology: focal haemorrhages, necrosis of haematopoietic elements in kidney & spleen, submucosal odema of intestine & stomach
Confirmed by isolation of virus
Use FHM, BB or RTG cell lines
Serum neutralization test
Note that history , gross signs and histopathology are all non specific
Prevention and Control:
Prophylatic use of antibiotics
Quarantine country
Treatment: experimentally –injected antibiotics reduce mortalities

Lymphocystis

Cottonwool disease
Aetiology: Lymphocyctis virus
Replication on fibroblast
Epizootiology : Species effected- many species , marine most commonly infected , but also freshwater & ornamental fish
Reservoir: infected fish
Transmission: direct contact
Occurance: lesions seen in 5-30% of some wild fish populations
Geographic distribution: worldwide
Gross signs: the virus infection does not usually result in death , economics losses occur due to consumer rejection of the affected fish, raised growths that appear to consist of small many white nodules on the skins and fins, occasionally single white nodules are seen in the internal organs, over time these lesions grow, necrotise and become secondarily infected by bacteria.
Pathology: lesions consists of massively enlarged fibroblasts (2mm).
Histopathology: dark blue inclusions in cytoplasm, 3 months after infection see a host response , a hyaline capsule around the enlarged fibroblast
Diagnosis: gross signs and histopathology
Isolation can be difficult unless primary cell lines from infected species are used
Prevention & Control: not a major problem but common
If present at a cage site, remove infected fish and disinfect nets etc.
Treatment: At early stage of infection by surgically removing the raised growths and disinfecting the resulting wound with acriflavine.


Epizootic Haematopoeitic Necrosis ( EHN)

Aetiology: Iridovirus
Host range: Redfin perch ( Perca fluviatis), Rainbow trout ( Oncorhynchus mykiss)
Mosquito fish ( Gambussia affins), Silver perch ( Bidyanus bidyanus)
Geograhics distribution: restricted to mainland Australia
Clinical Signs: No specific clinical signs
Mortalities are characterized by necrosis of liver ( with or without white spots), spleen , haemtopoeitic tissue of kidney and other tissue
Distruption of blood function, leads to osmotic imbalance, haemorrhagic lesions, buildup of body fluids in body cavity
Assoc. water quality, temperature
Diagnosis: Isolation of EHNV, ESV and ECV in cell culture
Confirmation: neutralization test, indirect fluorescent antibody test, enzyme-linked immunosorbent assay ( ELISA), polymerase chain reaction (PCR) & sequencing



Infectious Haematopoietic Necrosis

Aetiology: Rhabdovirus
Host range: rainbow or steelhead trout & Pacific Salmon
Geographical Distribution: North America, Europe & Asia
Transmission: vertical & horizontal
Clinical Signs: dark discolouration of body, distended abdomen, haemorrhage at the base of fins, operculum and around eyes “ pop-eye”, weaked swimming ability, white discharge from anus
Pathology: IHNV multiplies in endothelial cells of blood capillaries, spleen, kidney cells, which results in osmotic imbalance as well as systemic haemorrhagic lesions pale internal organs and or pin point bleeding in the musculature and fatty tissues
Kidneys, spleen, brain and digestive tract are the sites where virus is most abundant during advanced infection
Diagnosis: gross observations, histopathology, virology, ELISA, TEM

Viral Encephalopathy and Retinopathy( VER)

Also known as Striped Jack Nervous Necrosis Virus ( SJNNV), Viral Nervous Necrosis ( VNN), Fish Encephalitis Virus ( FEV)
Aetiology: nodavirus
Host Range: cultured marine fish ( seabass, turbot, halibut, Japanese parrotfish, red- spotted grouper, striped jack, Japanese flounder, brown spotted grouper )
Geographic Distribution: Asia, Mediterranean, Pacific
Clinical Signs: VER affects nervous system
Abnormal swimming behaviour, swimming bladder hyperinflation, reduced feeding, changes in colouration & mortality
Diagnosis: gross observations, histopathology ( vacuolization in brain or retinal tissues)


Fish Disease- Fungus

Integumentary Mycoses

Gills or skin following some kind of damage to the epithelium
Agent: Saprolegnia sp.
Culture: sabourauds agar
Epizootiology: Species affected-all freshwater sp & occasionally brackishwater/marine fish
Reservoir: normal inhabitant of water and oil
Transmission: motile zoospores in water
Occurance: any age
Important problem in hatcheries and aquarium
Never a primary infection, always follows damage to the gills/ skin or a physiological change
Geographic distribution: worldwide
Gross signs: circular, superficial, grayish white, cotton wool like growths on the fish these collapse when the fish is removed from water
If bacteria also present, lesions have haemorrhagic appearance
If gills affected, see signs of respiratory insufficiency
Pathology: death due to osmotic shock, hyphae invade stratum spongiosum & spread laterally over the dermis, epidermis shows oedema, spongiosis & necrosis
Diagnosis: gross signs, fungi isolated & cultured
Prevention and control : As Saprolegnia is an ubiquitous and secondary invader, control of primary factors reduce the incidence of fungus infections
Treatment: Malachite green, Methylene blue, Salt

Fish DIsease Again

Fish Diseases – Bacteria

1. Cytophagaceae
• Columnaris Disease


2. Enterobacteriaceae
• Edwardsiela septicaemia
• Enteric Redmouth (ERM)

3. Vibrionaceae
• Vibriosis
• Furunculosis
• Motile Aeromonad Septicaemia

4. Pasteurellaceae
• Pasteurellosis

5. Pseudomonadaceae
• Pseudomonas

6. Gram positive Fish Pathogens
• Streptococcal Infections

7. Acid Fast Pathogens
• Mycobacteriosis




Columnaris Disease

• Agent: Flexibacter columnaris
• Morphology: Gram negative, long,thin,aggregates in mounds on slides
• Culture: grows well on cytophaga agar, yellow colonies, fried egg appearance, optimum temp 15C.
• Epizootiology: 36 different species, salmonids and catfish most significant
• Reservoirs: wild fish
• Transmission: horizontal, water, experimental via moribund carcasses
• Environmental factors: elevated temps, temps depends on host species, usually 15C, severity increases with temp, high pH, hard water, organic matter, cleanliness important, crowding


• Patho: lesions confined to head, back, gills, starts as raised whitish spot distal on fins, gills; gradually develops into larger ulcer, bacteria isolated from leading edge of ulcer; skin eventually erodes away, exposing muscle; death rapid if necrosis/lesions are on gills due to respiratory problems, highly virulent strains cause death w/out lesions

• Dx: long, thin gram negative rods from lesions; rhizoid colonies on cytophaga agar; haystacking, clinical signs & serology
• Ctl; improved environment, cooler water temp, increased oxygenation , decreased crowding, organics, reduced stress
• Tx: internal via oxytetracycline in feed, sulfonamides


Edwardsiella Septicemia

• Agent: Edwarsiella tarda
• Morphology: Gram negative, rod
• Culture: gram negative rod, motile by flagella, grows well on most standard media(TSA, BHI), produces small transparent and smooth circular colonies at 35C ferments glucose and produces gas , indole positive (diff. From E.Ictaluri)
• Epizootiology: southern U.S, SE Asia , Pacific NW, many warmwater species of fish
• Reservoir: pathogen of or can be carried by many vertebrates and invertebrates
• Transmission: horizontal
• Environmental factors: higher than 30C water, organics, crowding; salmonids at temps greater than 20C

• Patho: fish large 38 cm( high value), slow progress, low mortality unless fish stressed (5--50%mort) , causes development of gas filled abscesses containing sulfide; mild infections exhibits small cutaneous postlateral lesions, progressing as abscesses in muscles of flank or caudal peduncle, lose control of posterior portion of body
• Dx: isolation from kidney into TSA or BHI; presumptive as gram negative, motile rod, motile via use of flagella, catalase +ve, cytochrome oxidase –ve, & serology
• Ctl: good culture environment
• Tx: oxytetracyline at 2.5g/45 kg feed /fish/day for 10 days


Enteric Redmouth Disease(ERM)

• Agent: Yersinia ruckeri
• Morphology: Gram negative , rod , motile by flagella at 18 - 27C, can become filamentous in order cultures
• Culture: std media, 22-25C, cytochrome oxidase –ve, no gas/H2 S in TSI, ferments glucose
• Epizootiology: originally Idaho, now apparently ubiquitous; mainly rainbows but also cyprinids
• Reservoirs: natural host , carriers with low grade mortality
• Transmission: horizontal
• Environmental factors: large scale epizootics occur due to stress , low DO, poor environment , grading ; reduced 14C
• Pathology: infected fish become sluggish, darker; severe congestion /hemorrhages of tissues of head /mouth, stomach filled w/water colorless fluid, intestines w/yellow fluid , petechial hemorrhages of internal orgs, spleen dark/enlarged
• Dx: isolation from kidney onto TSA or BHI plates at 20-25C for 24-48 h, Gram negative, motile rod, cytochrome oxidase negative , no H2S in TSI & serology
• Ctl: prevented from avoidance , hygiene, detection of carriers; immunization available and best management tool; can disinfect eggs w/iodophires (25 ppm), sulfamerazine + oxytetracycline ( 20g/100kg/f/d; 5g/100kg/f/d for 5 days each)



Pseudomonas fluorescens

• Agent: Pseudomonas fluorescens
• Morphology: Gram negative , rod motile via polar flagellum
• Culture: std media , round glistening colonies w/undulating edge, radial striations, easily seen green pigment under UV light (pseudomonas F agar), cytochrome oxidase +ve, catalase +ve, strict aerobe, grows at 18-25C
• Epizootiology: worldwide, all fish susceptible, problem for aquarium fish
• Reservoirs: mud and water; infected or carrier fish and others( frog)
• Transmission: horizontal
• Environment factors: stress, mainly elevated temps
• Patho: hemorrhages and necrosis of internal organs & external lesions
• DX: isolation from kidney on TSA or BHI &id
• Ctl: remove stressor
• Tx: oxytetracycline at 50-75 mg/kg/f/day for 10 days


Motile Aeromonad Septicaemia (MAS)

• Agent: taxonomy confused, Aeromonas hydrophila (more than 10 other species claimed); G-motile rod w/polar flagella; oxidase +ve, catalase +ve, glucose fermenter
• Culture: TSA, BHI; can grow at 4C but best at 18-25C; white, circular, convex colonies, often confused w/Citrobacter
• Epizootiology:worldwide in fw, all fw species susceptible, others such as frogs, alligators, snails , prawns
• Reservoirs: freshwater w/high organics loads , usually in sewage, normal gut flora of healthy fish; diseased fish/frogs; survivors are carriers
• Transmissions:horizontal
• Environment factors: stress from crowding, variable temps, changes in weather, rough handling, low DO, high organics
• Patho: usually hemorrhages + necrosis internal organs + necrotics lesions on skin/muscle = G-septicemias
• Superficials circular or grayfish- red ulcerations
• Lesions around mouth similar to ERM
• Hemorrhages of fins ,exopthalmia
• Internal pathology: swollen, soft kidney; petechiae of musculature, intestines free of food
• Dx: isolation from kidney into TSA or BHI, Gram negative, motile rod, cytochrome oxidase +ve, ferments in glucose, no fluorescent pigment
• Ctl: prevention via good management
• Tx: oxytetracycline at 50-75mg/kg fish/ day for 10 days


Furunculosis

• Agent: Aeromonas salmoncida (produced pigment)
• Morphology: Gram negative, rod, nonmotile
• Culture: TSA/BHI, brown pigment, grows well at 18-25C, small white round raised convex colonies , oxidase+ve, non-motile, ferments glucose but no gas
• Patho: both virulent and avirulent strains, produces endotoxin
• Epizootology:salmonids cultured in fw
• Reservoirs: obligate fish pathogens, found in waters w/infected or carriers fish
• Transmission: horizontal
• Environmental factors: severity increases w/temp, nutrition, handling stress
• Patho: similar to other G-, septicaemia conditions w/hemorrhaging, necrosis of internal organs, external lesions
• External patho: focal necrosis in muscle develops to abscess, hemorrhages at base of fins, bloody discharge from vent, bleeding from gills
• Intenal patho: petechiae in body musculature, congestion of posterior intestine, no inflammatory response
• Dx: isolation from kidney into TSA, BHI; gram negative, non-motile rod, brown diffusible pigment, oxidase +& serology
• Ctl: avoidance via clean water/fish; several vaccines on the market
• Tx: oxytetracyline at 50-75mg/kg fish/day for 10 days



Vibrosis

• Agents: Vibrio parahaemolyticus, V.alginolyticus, V. anguillarum
• Morphology: Gram negative, curved/ straight rods, motile with a single polar filament
• Epizootiology: all marine /brackish water fish, including ornament marine fish
• Reservoir: wild fish carriers of pathogenic strains & as a normal inhabitant of the GI tract
• Transmission: horizontal
• Occurance: all ages assoc with high temperatures, rapid salinity changes, handling & ectoparasite damage
Disease is always preceeded by some from of stress
Level of mortalities & acuteness of disease depends on temperature, strains virulence, fish species & stressor
100% mortalities in fry and fingerlings, but in epizootic more than 50% mortality
• Clinical signs:
• Peracute disease: only seen in young fish, anorexia, darkening of hyperaemia of the skin, sudden death
• Acute & Chronic disease: older fish, darkening, lose balance & jump out of water, hyperaemia around vent, sides of operculum , caudal fins & base of fin , haemorrhage of the eyes & gills, petechia on the body surface which develop into haemorrhagic ulcers which may extend down into the skeletal muscles in the chronic forms of the diseases , exophthalmia is occasionally seen.

• Patho: haemorrhages through out the internal organs, hyperamics intestinal tract, enlarged and liquefied spleen, liquefaction of the kidney.

• Histopathology: foci of necrosis in the liver, spleen and kidney
In peracute disease see a severe cardiac myopathy


• Diagnosis: based on clinical signs, pathology and history
Confirmed with isolation
Primary isolation should be made on TSA(1.5%) NaCl at 20-25C and 24-48h
A presumptive diagnosis can be made if the isolate is a Gram negative , short /curved rod, motile , cytochrome oxidase +ve, produces acid but no gas in glucose O/F medium
Confirmed if the TSA isolate is sensitive to vibrostat 0/129
Antisera are available for vibrio in temperate regions

Further biochemical testing for further identification

• Prevention & Control:
Avoid handling & high stocking densities at risk periods of high temperatures or sudden salinity changes
General sanitation procedures
Commercial vaccines available
Treatment: Antibacterial can be incorporated in feeds
But the diseased fish may have stopped eating and bacteria maybe resistant to the antibacterial used

Vibrio Infections of Fish

Vibrio infections usually occur in fish from
marine and estuarine environments, and have been
reported throughout the world. Occasionally,
vibriosis is reported in freshwater fish. The disease
can cause significant mortality (>=50%) in fish
culture facilities once an outbreak is in progress.
Common names for Vibrio infections of fish include
"red pest" of eels, "salt-water furunculosis", "red
boil", and "pike pest". Vibrio infections can spread
rapidly when fish are confined in heavily stocked,
commercial systems and morbidity may reach 100%
in affected facilities.

The disease is caused by gram negative bacteria
in the family Vibrionaceae. This group of bacteria
includes two important genera which can be
significant fish pathogens. The genus Aeromonas
includes several species which are important
pathogens of freshwater fish, although they
occasionally cause disease in marine species.
Bacteria in the genus Vibrio are important pathogens
of marine and brackish water fish, although they
occasionally are reported in freshwater species.
Seven species of Vibrio have been associated with
disease in fish:

• V. anguillarum (isolated most commonly from
marine and brackish water fish);
• V. ordalli (an atypical strain of
• V. anguillarum , sometimes referred to as
Biotype 2);
• V. damsela (isolated from damsel fish);
• V. carchariae (isolated from sharks);
• V. vulnificus (reported in Japanese eels); and
• V. alginolyticus (reported from cultured
seabream in Israel).


A new, extremely pathogenic Vibrio infection of
cold-water marine fish (i.e., salmon) is caused by V.
salmonicida and is referred to as "cold-water vibrio"
or "hitra" disease. Cold-water vibrio has not been
reported in warm-water fish and will not be discussed
further in this publication.

Vibrio species are also known to cause disease
in humans, most often following the consumption of
contaminated shellfish. Most serious illness is usually
limited to individuals with a suppressed immune
system.

Signs of Infections
The signs of vibriosis are similar to many other
bacterial diseases of fish. They usually start with
lethargy and a loss of appetite. As the disease
progresses, the skin may become discolored, red and
necrotic (dead). Boil-like sores may appear on the
body, occasionally breaking through the skin surface
resulting in large, open sores. Bloody blotches
(erythema) are common around the fins and mouth.
When the disease becomes systemic, it can cause
exopthalmia ("pop-eye"), and the gut and rectum may
be bloody and filled with fluid. It should be noted that
all of these "signs" can be caused by other bacterial
diseases, and are not proof of a Vibrio infection.


Treatment
Before any treatment with antibiotics, a thorough
investigation of water quality and husbandry
practices should be conducted. Removal of
underlying problems is essential to successful
resolution of the problem. Occasionally, removal of
contributing factors (i.e., poor water quality) will be
all that is required to control the infection, but in most
cases it is prudent to treat an active Vibrio outbreak
with antibiotic therapy.
The selection of an antibiotic should be based on
results of an in vitro sensitivity test. There are two
antibiotics which have been approved by the Food and Drug Administration (FDA) for use in food fish (catfish and salmonid.)

Terramycin contains the antibiotic oxytetracycline. It
is sold for fish in a sinking feed and should be fed for
10 days. Fish which have been fed Terramycin should
not be eaten for at least 21 days following treatment
(the legal withdrawal time) to ensure complete
elimination of drug residue from edible tissue. Romet
is a potentiated sulfonamide which contains two
drugs, sulfadimethoxine and ormetoprim. It is sold
for fish in a floating feed and should be fed for 5 days.
The withdrawal time of Romet for catfish is only 3
days because the drug is bound in the skin of the fish
which is removed when catfish are cleaned. In
salmonids, however, the withdrawal time is 6 weeks
because the fish are not skinned during processing.
Either drug will be effective if the strain of Vibrio is
sensitive to it and if sick fish ingest enough
medication to maintain the drug in the bloodstream
throughout the treatment period.
In pet fish, the traditional treatment for bacterial
disease has been the addition of antibiotics to tank
water. This practice should only be pursued as a last
resort. Antibiotics should be delivered to fish in
medicated feeds or by injection. Flake foods which
contain Terramycin or Romet are commercially
available through pet retail outlets for use in
aquarium fish. Because there is no FDA-approved
antibiotic available for use in pet fish, veterinary
supervision of antibiotic therapy is recommended. If
fish do not respond to antibiotic therapy within 48
hours a sample of sick fish and water should be sent
to a fish disease diagnostic laboratory to confirm the
original diagnosis and determine whether additional
problems, such as parasitism, may also be present.

Penyakit yang boleh menyerang Lintah

Disease

Reported to be vectors of trypanosomes and Cryptobia in freshwater fish. Suspected of being
capable of transmitting Trypanosoma brucei and T. equiperdum to humans. Concern about
passing strains of hepatitis prevents reuse of medicinal leeches.

Types of Leeches

•500 species of leeches world wide
•63 species in North America
•35 species in Ontario

•One species is the primary leech used for bait
–Bait leech or ribbon leech (Nephelopsis obscura)

•Other swimming leeches commonly caught in traps

–Tiger leech (Erpobdella punctata)
–Horse leech (Haemopsis sp)
–Medicine leech (Macrobdella decora)


Ribbon Leech
Description
•Most common
•Aquatic and active swimmer.
•Slate gray or gray brown in colour
•Body flattens to firm ribbon-like edges


Habitat
–Ponds and marshes rich in organisms.
–Shallow littoral zone.
–Feeds mainly at night.


Life History
–Reproduce in mid summer of second year.
–Develop in safety of cocoon.
–Dormant over winter
–Trappable size following spring

Feeding
–Feeds on small invertebrates.
–Predacious –jaws and muscular pharynx
–Opportunistic feeder


Horse leech
–Is used for bait
–Predator and scavenger feeder
–Greenish to dark brown
–Identified by five pair of small black eyes on top of head.


Medicine leech
–Black with reddish orange spots on back
–Reddish orange belly

Leech BioloGy

Other State Of Leeches


Annelids or segmented worms
•32 segments regardless of size
•Suckers on each end of their body
•Pigmented skin
•Dull gray or black to bright orange
•Active swimmers and creepers


Parasitic or predatory
•Parasitic blood suckers gorge and may remain dormant for weeks
•Predatory leeches feed on worms, invertebrates, insects, worms and snails.


Where to Find Leeches

•Primarily fresh water.
•Warm protected shallows.
•Maximum abundance –2Metres
•Avoid Light.
•Nocturnal
•Water temperature is not considered a limiting factor.
•Low oxygen levels deplete leech growth.
•Leeches retreat to deep water in the winter
•Most abundant in ponds that do not contain fish.
•Ponds with bullheads, perch or sunfish contain few leeches.
•Fat head minnows benefit leech habitat.
•Ponds shallow with silt
•Substrates and abundant aquatic vegetation near shore.
•Beaver ponds are ideal habitat

Pemakanan Lintah

Secara amnya, lintah menghisap darah semua hidupan.

oleh itu, saya bagi sedikit list sekadar info.

sebarang keraguan, boleh diaju kan soalan..


Jenis-jenis makanan lintah::

Cacing

Siput

belut

Katak

Burung

Organisma Kecil

Lembu

kura - kura

Hati ayam ( tetapi boleh menjejas kan kualiti air)


Pemberian makanan perlu lah bersistematik supaya tiada gangguan pada kualiti air.

Seeloknya Jangan terlalu Mengambil Mudah Selepas Pemberian makanan.

Lintah$$

Aspek Penting Yang perlu Diambil ::


Keperluan Tanah dan Iklim

Penyediaan Tanah

Kualiti air

Penternakan

Penjagaan dan Pemakanan

Habitat ?Lintah yang sesuai@@

list of engine sites

List of Search Engines

You may submit your site URL to these search engines for Free. If you lack the time, submit your site to the top few leading search engines.



Google
Yahoo! Search
Microsoft Live Search
Alexa Web Search
Baidu (Chinese search engine)
ExactSeek
SearchSight
Scrub the Web
EntireWeb
Gigablast
Exalead
SearchKing
whatUseek
AnooX
Splat Search
Walhello
SearchIt
email Mozdex
Jayde
Infotiger
Abacho (European search engine)
Submit-one
TowerSearch

BIOREMEDIATION

Bioremediation is a combination of two words – bio, short for biological, and remediation, which means to remedy.
Bioremediation usually refers specifically to the use of microorganisms.
Process that uses naturally occurring or genetically engineered microorganisms such as yeast, fungi and bacteriato transform harmful substance into less toxic or nontoxic compound.
Bioremediation uses living organisms to clean up contaminated soil or water.


Types of Bioremediation
Biostimulation
Bioaugmentation
Intrinsic Bioremediation

Nutrients and oxygen - in a liquid or gas form - are added to contaminated water or soil to encourage the growth and activity of bacteria already existing in the soil or water.

The disappearance of contaminants is monitored to ensure that remediation occurs. 

Bioaugmentation is more commonly and successfully used on contaminants removed from the original site, such as in municipal wastewater treatment facilities.

To date, this method has not been very successful when done at the site of the contamination because it is difficult to control site conditions for the optimal growth of the microorganisms added.


Bioaugmentation is more commonly and successfully used on contaminants removed from the original site, such as in municipal wastewater treatment facilities.

To date, this method has not been very successful when done at the site of the contamination because it is difficult to control site conditions for the optimal growth of the microorganisms added.


Intrinsic Bioremediation
Also known as natural attenuation, this type of bioremediation occurs naturally in contaminated soil or water.

This natural bioremediation is the work of microorganisms and is seen in petroleum contamination sites, such as old gas stations with leaky underground oil tanks.


Anabolism – Building Up
In anabolism, chemicals taken up by the microorganism are used to build various cell parts. Carbon and nitrogen are the basic chemicals in the proteins, sugars and nucleic acids that make up microbial cells.

Microorganisms take up carbon and nitrogen from the soil, water, and air around them. In order to take up nutrients and make them into cell parts, a microorganism needs energy. This is where catabolism comes in.


Catabolism – Breaking Down

Catabolism allows microorganisms to gain energy from the chemicals available in the environment.

Although most microorganisms are exposed to light and to chemical energy sources, most rely on chemicals for their energy.

When chemicals break down, energy is released. Microorganisms use this energy to carry out cellular functions, such as those involved in anabolism



Anabolism and Catabolism's Role in Bioremediation

Chemicals present at contaminated sites become part of the anabolism and catabolism process.
For example, hydrocarbons (part of the carbon family) present at sites with petroleum products can be taken up by microorganisms and used as building blocks for cell components.

Other chemicals that are important to a microorganism include chemical compounds in the phosphorus, potassium, calcium and sodium group.

Microorganisms also need trace elements of other chemicals, including chromium, cobalt, copper, and iron, all of which can be available in abundance at contaminated sites.

Natural Defenses Against Infection

First line defense line against disease is skin, mucus, and other passage connection connecting internal and external environment
If the pathogen pass this first line defense, than the second line defense, which is provided by natural or innate immune mechanisms.
In this case, our own cells and the chemicals they produce seek out, identify and eliminate the pathogen.
These very general and non-specific responses are critical to the maintenance of good health.

On occasion, a pathogen can get past fish bodies’ primary protective mechanisms if it is present in very large numbers or if it has evaded or suppressed these processes.
Stronger protection is needed and we respond by mounting an acquired immune reaction specific to the pathogen.
These responses involve a variety of types of cells found in the blood and tissues, and can require a week or more to become established.
Acquired immunity consists of antibody and cell-mediated responses.


An acquired immune response can result in either short-term or long-term protection against a specific pathogen and, perhaps, against some of its close relatives.
In the case of long-term protection, re-exposure to the same pathogen weeks, months or years later reactivates the response mechanisms laid down during the original exposure.
This reactivation leads to rapid, effective elimination of the agent, often without clinical symptoms or signs of infection. When specific immunity results from unintentional exposure to agents in the environment, we refer to the resulting protection as being passively acquired immunity.


Intentional exposure to such an agent or its components through vaccination is known as actively acquired immunity
A humoral response and a cellular response. The humoral response is the stimulation of serum protein molecular synthesis homologous specific to the antigen causing the synthesis. These serum protein molecules are called antibodies

A weak bacteria will enter into the body of the fish
All potential pathogens contain antigens. The introduction of antigens by a pathogen is what stimulates the antibody response of the host
The immune system will be respond to the bacteria, and reproduce the antibody of the bacteria.


The specific immune will be produce to created future protection
The cellular response to antigen stimulation is a sensitization of cellular elements of the reticuloendothelial system.

Vaccine system

Vaccines are various preparations of antigens derived from specific pathogenic organisms that are rendered non-pathogenic.

They stimulate the immune system and increase the resistance to disease from subsequent infection by the specific pathogen.

IMMUNE SYSTEM

The main component of the immune system is the lymphatic system. Small organs called lymph nodes help carry lymph fluid throughout the body.

Lymph fluid contains lymphocytes and other white blood cells and circulates throughout the body.

WHY RECOMBINANT


Chromosomes are composed of a series of genes linked together on a molecule of DNA. If the combination of alleles on a chromosome could not be changed the genetic variability available for natural selection would be severely reduced.

The new combinations of chromosomal alleles are a major source of the genetic variation used in natural selection. Other recombinant based phenomenon include the generation of antibodies and the movement of "jumping genes" to new chromosomal locations.
Recombinant vector vaccines. A vaccine vector or carrier is a weakened bacterium into which harmless parts of genetic material from another disease-causing micro-organism have been inserted.


Different types of vaccines exist

Inactivated vaccines are the most common in aquaculture. They are produced by inactivating the disease-causing micro-organism with chemicals or heat.

Live, attenuated vaccines. To make a live, attenuated vaccine, the disease-causing microorganism is grown under special laboratory conditions that cause it to lose its virulence or disease-causing properties. Intervet’s Aquavac ESC®, a vaccine used against Edwardsiella ictaluri in Channel catfish (Ictalurus punctatus) in the USA is an example.

Subunit vaccines are a more modern type of vaccine, developed from antigenic fragments that are able to evoke an immune response. Subunit vaccines can be made by purification of parts of the actual micro-organism or they can be made in the laboratory using genetic engineering techniques. An example is Intervet’s Compact® IPN used against infectious pancreatic necrosis virus infections of salmon in Chile.


TYPES OF VACCINE
1) Norvax® Strep Si
2) Slice* Premix
3) Fujipenin* 40 
4) Aquaflor*-L
5) Aquaflor*
6) Bicomarin* 5% Powder 
7) Isran* Soda
8) Tribrissen* 40% Powder 
9) AquaVac* ERM 
10) AquaVac* ERM Oral 
11) AquaVac* FNMPLUS
12) AquaVac* Furovac 5 
13) AquaVac* Furovac 5 Oral 
14) AquaVac* Furovac 5 Vibrio 
15) AquaVac* Vibrio 
16) AquaVac* Vibrio Oral 
17) AquaVac* Ergosan* 

Probiotic In fish Farming

Probiotics are dietary supplements containing potentially beneficial bacteria or yeast, however lactic acid bacteria (LAB) are the most common microbes used. (Wikipedia)
Term “probiotic” inevitably referred to gram-positive bacteria associated with the genus Lactobacillus. (Fuller R. A, 1989)
"live microorganisms administered in adequate amounts which confer a beneficial health effect on the host". (FAO
Are generally called the bacteria which can improve the water quality of aquaculture, and (or) inhibit the pathogens in water there by increasing production.
"Probiotics", "Probiont", "Probiotic bacteria" or "Beneficial bacteria" are the terms synonymously used for probiotic bacteria

Types of Bacteria

BIFIDOBACTERIUM
-Normal inhabitants of the human and animal colon.

LACTOBACILLUS
-Normal inhabitants of the human intestine and vagina.

LACTOCOCCUS
-Found in dairy products and is commonly responsible for the souring of milk.

SACCHAROMYCES
-Treat diarrhea associated with antibiotic use.

STREPTOCOCCUS THERMOPHILUS
-Found in milk and milk products. Used in the production of yogurt.

ENTEROCOCCUS
-A probiotic strain that has been used in the management of diarrheal illnesses.


Benefits of Probiotics

Provide additional nutrients thereby reducing feed costs.
Maintaining desired conditions within the culture environment.
Eliminate the presence of stressors like NH3, NO2, NO3.
For stability and control of microbial populations.
To maintain stable water quality parameters.
To prevent bacterial infection caused by Vibrio and other Eubacterial phatogen and Viral infection.

Yeasts (Saccharomyces cerevisiae, Candida utilis, Kluyveromyces marxianus) and yeast products improving feed attractability, supporting growth by producing vitamins, minerals, nucleic acids and by stimulation of beneficial gut flora.
Improves growth and feed conversion
Improves survival rate of aquatic species.
Reduces stress and disease susceptibility
Reduces the need for expensive drugs

Selection Criteria for Probiotics
Antagonism to pathogens – producing anti-microbial substances like organic acids, hydrogen peroxide, or siderophores.

Must have the capacity to colonize the fish by adhesion, and to produce important substances, like vitamins. –to promote the growth or to protect fish against bacterial pathogens.

The microorganisms should be viable for long periods under storage as well as field conditions.

Probiotic microorganisms have to be non-pathogenic and non-toxic in order to avoid undesirable side-effects when administered to fish. (Ali, 2000)

Anatomy of BloodFeedig

Leeches are best known for their bloodfeeding habits and for their use in medicines.
When a leech is attached to your skin, it does not necessarily start feeding straight away. First it has to find a nice soft place to feed from that has to "taste" just right. The palm of your hand for example, it not really a good place for them since the skin is usually quite thick. Medicinal leeches have three muscular "jaws", one dorsal and two ventrolateral jaws, each of which has a row of fine "teeth" or denticles on it. By moving those jaws back and forth across your skin, they make a fine incision and cut the underlying capillary beds, thus causing blood to pool.

The resulting wound from a leech bite is not very large, and nor is it very deep. However, because of the circular oral sucker and because of the arrangement of the three jaws, it does provide you with a rather prestigious Mercedes-Benz-like mark on your skin! Leeches, of course, don't spend a good deal of time looking for humans to feed on. After all, we don't really spend a great deal of time in the water so a leech might wait a long time.

Leeches(more Fact)

What do they look like?

Leeches are segmented worms with suction cups at each end. Their bodies are flattened, much wider than they are thick. They are usually dark colored, often brown or sometimes yellow or dark green. Some species have no markings, others have spots and stripes. The smallest leeches grow no more than 5 mm, but some big species may get to be more than 25 cm long. Many leech species have one or more pairs of eyes visible on the top of their front end. Leech species that suck blood have sharp teeth. Predatory species may have teeth, or may have only crushing jaws.


What kind of habitat do they need?



Most leech species are found in shallow, slow-moving freshwater, but some live in the oceans, and a few live in moist soil on land.

How do they grow?

Leeches lay eggs in cocoons, and the babies that hatch out look and behave like little adults. They don't change much as they grow, they just get bigger. Leeches that live in habitats that freeze or dry out during part of the year bury themselves in mud and stay dormant until the habitat improves. Leech growth rate is strongly affected by temperature and food supply. Most species can mature in a few weeks or months if conditions are good.

In most species, each leech has both male and female sex organs, and can both lay eggs and give sperm to another worm. After mating, each worm produces several cocoons containing eggs. The cocoons are protected with a tough layer of protein, and contain one or a few eggs (depending on the species). Most species attach their cocoon to vegetation or debris underwater, but a few put them in damp soil. Leeches reproduce and grow at very different rates, depending on which species they are, the amount of food they get, and the temperature of the habitat they live in. Most grow faster in warmer temperatures.


How long do they live?

Some leeches complete their life cycle in a few years.


How do they communicate with each other?

Leeches have very poor vision (often they can only tell the strength of light), but are very sensitive to touch. They also have a strong sense of taste. They cannot hear, but are sometimes very sensitive to vibrations. They communicate with other leeches chemically, and by touch.



What eats them and how do they avoid being eaten?

Known predators

* fish ( eat leech eggs )
* birds
* large aquatic insects
* snakes
* other leeches
* snails (eat leech eggs)
* mites (eat leech eggs)

Most leeches hide while resting, staying in thick plant growth or hiding in mud. Many leech species are nocturnal ( active at nite), this helps them avoid predators and locate resting prey. If attacked, some species swim away as fast as they can, others go limp and "play dead," others curl into a ball and sink to the bottom. When parasitic leeches attach to their host, they sometimes select places that are hard for their host to reach.


What roles do they have in the ecosystem?

Leeches are sometimes important members of aquatic food webs. They are mid-level consumers, eating smaller animals and in turn being eaten by larger predators.

'I am still the Special One', says Mourinho

Jose Mourinho may no longer have a club to manage, but receiving a P45 has not dimmed the former Chelsea boss's opinion of himself and the Portuguese still believes he is the ‘Special One’.

Mourinho, who left Stamford Bridge last week, made his now famous proclamation upon his arrival in England and believes he proved himself to be just that during his three-year stay.

Chelsea enjoyed the most successful period in their history under Mourinho, the former Porto manager leading them to their first league title in 50 years in his first season in charge before repeating the feat the following season.

“I took a chance in saying that I was special, but I think there are now a lot of people who would sign up to that,” Mourinho said.

“I think I’m still special. I achieved good things and it was a fantastic period in my career. I’ll try to forget the bad things and remember the good ones, which are endless.”

Mourinho, who has been replaced by Avram Grant, admits the past week has proven an emotional experience but insists he will always remember his relationship with the club’s players and supporters.

“Yes, I cried,” he said. “I tend to say that I have a family at home and another at work. I’ve always had a relationship of love with the players and fans. I won’t forget them and they won’t forget me.”

Hasilkan Laman Web Sendiri.

Antara laman blog yang boleh anda cuba ialah Blogger (http://blogspot.com), WordPress (http://wordpress.com), MSN spaces (http://spaces.msn.com) dan LiveJournal (http://livejournal.com).

Laman blog ini biasanya mengkehendaki anda mendaftar sebelum boleh membangunkan laman. Kebanyakan laman blog mempunyai acuan atau reka letak yang sudah tersedia untuk dipilih.

Sementara IM atau Instant Messenger adalah khidmat yang disediakan oleh pembekal email seperti Yahoo! Mail, Google Mail dan Hotmail.

Jika sudah mempunyai alamat e-mel dengan pembekal tersebut, anda hanya perlu pindah turun perisian aplikasi untuk memulakan perbualan.

Sebagai contoh, andaikan anda sudah mempunyai alamat e-mel dengan yahoo.com. Anda hanya perlu masuk ke http://im.yahoo.com dan pindah turun

aplikasi Yahoo Messenger. Dwiklik dan ikuti langkah yang dibentangkan.

Selesai pemasangan, anda boleh log masuk menggunakan alamat e-mel Yahoo! yang ada.

Langkah pencegahan atau pengurangan kemasukan iklan ketika melayari internet...

Beberapa langkah pencegahan atau pengurangan kemasukan iklan boleh dilakukan termasuk:

- pastikan OS menggunakan patch terkini kerana program malware akan mengeksploitasi setiap kelemahannya;

- jika menggunakan Internet Explorer, pastikan gunakan patch terkini. Anda boleh juga menggunakan browser alternatif seperti Mozilla Firefox (mozilla.com) atau Opera (opera.com);

- baca kotak popup sebelum klik "OK". Ada juga iklan yang menyerupai kekotak dialog dari windows. Pastikan anda klik 'X' dan bukan "OK";

- jika menggunakan Firefox, anda boleh dapatkan perluasan seperti "NoScript" untuk membenarkan penggunaan Javascript di laman-laman web tertentu yang anda percaya. Untuk mengelak iklan dari jenis flash pula, anda boleh dapatkan perluasan "Adblock";

- jangan melayari laman web yang diragui, seperti porno, cracks, dan warez;

- dapatkan program anti spyware seperti Spy Bot Search & Destroy, IE-SPYAD, Spyware Blaster dan Windows defender (masih dalam beta) untuk mengesan program yang diragui. Anda juga boleh menggunakan program berkenaan serentak tidak semua program boleh mengesan segala spyware dan malware;

- browser terkini seperti Firefox, Internet Explorer dan Opera, kini mempunyai pilihan untuk menghalang pop-up. Aktifkan ciri itu.

- jangan pasang program-program dari laman web yang diragui.

Christiano Ronaldo Biodata~

Cristiano Ronaldo (full name Cristiano Messias Ronaldo dos Santos Aveiro;
born 5 February 1985, Funchal, Madeira, Portugal)

is a Portuguese professional football player who plays his club football for Manchester United of England.


Full name: Cristiano Ronaldo dos Santos Aveiro

Nick Names Cris, Ron, Ronnie, The Sultan Of The Stepover

Date of birth: February 5, 1985 (Monday)

Place of birth: Funchal, Portugal

Height: 184 cm (6 ft. 1 in.)

His favourite movies: The Sixth Sense

His favourite actress: Angelina Jolie

His favourite colors: White and Red

His favourite number: 7

His favourite Cola: Coca Cola

Hair / Eyes : Light Brown / Brown

Religion : Christian - Catholic

Mother's Name : Maria Dolores dos Santos Aveiro

Father's Name : Jose Diniz Aveiro

Brothers : Hugo Aveiro

Sisters : Elma Aveiro and Katia Aveiro

Uncle : Alex Aveiro

Cell Phone : Nokia 6230

Cars : silver Porsche, red Ferrari 435

# Adverts: Has appeared in several Nike adverts
# Has appeared in a Suzuki TV advert.

He doesn't smoke!

# Scored Manchester United's 1,000th league goal against Middlesbrough FC.
# Filmography: 2006 FIFA World Cup Germany (2006) (mini) TV Series .... Himself
# Manchester United: Play Like Champions (2003) (V) .... Himself

Leech Fact@@^

Leeches...

its suck all of animal blood about 4 hours and will drop off after being full.

its can Be 5 times bigger than usual sizes.

Also had 3 types of Reproduction. Means Its lay cocoon,Fertilized the egg without

cocoon and lay the miniature.

the best thing i can describe about this leeches..leeches r an exotic animals.

bringing a lot of advantages especially in medicines.

Fakta Gigitan Lintah

adakah anda semua tahu tentang rupa gigitan lintah?

apa yang menariknya tentang lintah di malaysia..setelah digigit,

kesannya yang tinggal ialah bentuk Y atau pun mercedes benz.

rasanya jarang ada yang perasan pada kesan gigitan lintah.

sesetengah lintah di negara luar mempunyai gigitan V.

KerisPatih(MengenangMu+TapibuKan Aku

Lelaki ini (Anuar Zain)

Kasih, kenanganku
Ingatkah saat saat dulu
Kasih, apakah dirimu
Merasakan semua itu

Ke mana pun langkahku pergi
Ku masih melihat bayanganmu cintaku
Dan kemana pun arah anginku berlari
Hati ini masih kau miliki

Lelaki ini yang selalu mencintamu
Selalu, tanpa ragu
Lelaki ini yang selalu memuja
Hanya dirimu
Yang bertakhta dalam sanubariku
Sanubari ku
Aku yang mencintakan mu
Hanya dirimu…

Karena cintaku, tak berbatas waktu
Karena cintaku, tak mengenal jenuh hatimu
Hatimu…

Leeches Dances....Kitaro...Matsuri

Abstract Lintah

Kebanyakan lintah untuk perubatan boleh didapati di air tawar kerana lintah tidak mampu hidup pada pH 5.0 dan ke bawah iaitu tidak boleh hidup dengan keadaan tanah berasid. Lintah boleh hidup dalam keadaan kekurangan oksigen dan makanan. Kebanyakan lintah sukakan tanah yang berlumpur dan biasanya apabila musim kemarau, lintah – lintah ini akan bersembunyi di dalam lumpur untuk jangka masa yang lama. Lintah di Malaysia biasanya melepaskan telur di luar badan berbanding dengan lintah – lintah jenis lain. Lintah – lintah ini biasanya suka tempat yang lembap dan berada berdekatan dengan tebing-tebing sungai, tasik mahupun sawah padi. Tempat yang sesuai untuk telur lintah biasanya pada akar pokok kiambang, keladi bunting, kayu, batu dan lain - lain.

Lintah juga peka dengan sebarang pergerakan di dalam air dan kebiasaannya akan melekat pada mangsa dalam 40 – 120 minit dan akan jatuh apabila sudah kenyang. Sekiranya terkena gigitan lintah dan susah untuk menanggalkannya sebelum lintah kenyang, perkara yang harus ditekankan ialah pada bahagian mulut hadapan lintah tersebut. Letakkan jari pada bahagian hadapan mulut lintah tersebut dan dengan lembut tolak bahagian mulut hadapan lintah daripada tempat lintah tersebut melekat. Lintah jenis ini meninggalkan bentuk Y berbeza dengan setengah lintah yang akan meninggalkan bentuk V pada bahagian luka. Lintah ini mempunyai banyak persamaan dengan Hirudinea Medicinalis yang terdapat di luar negara kerana kedua – dua spesies ini mempunyai hubungan yang rapat.


To Be contiNued.

Leech LocoMation

DISEASES OF FISH

Lymphocystis Disease


A) Iridovirus
B) Observed in most freshwater and saltwater species
C) Clinically fish are presented with variably sized white to yellow cauliflower growths on the skin fins and occasional gills. Occasionally this virus may go systemic with white nodules on the mesentery and peritoneum.
D) Histopathology: Fibroblast undergoes cytomegaly with many basophilic cytoplasmic inclusion bodies and a thick outer hyalin capsule. The inflammatory response is variable but is usually a chronic lymphocytic inflammatory infiltrate.
E) The disease gains entry through epidermal abrasions. The virus infects dermal fibroblasts.
F) The disease is self-limiting and refractory to treatment. Nodules may last several months and cause infected fish to be susceptible to secondary bacterial infections. Reinfection can occur.

Herpesvirus salmonis (Herpesvirus disease of Salmonids)
A) Herpesvirus
B) Disease is observed primarily in fry of Rainbow trout.
C) Clinically the fish are lethargic with prominent gill pallor. Mucoid fecal casts are commonly observed trailing from vent.
D) Lesions: 1) Exophthalmus and ascites
2) Low hematocrit and numerous immature erythrocytes
3) Hemorrhage in eyes and base of fins
E) Histopathology:
1) Multifocal areas of necrosis of the myocardium, liver, kidney, and posterior gut (leading to cast formation
2) Syncytial cells involving the acinar cells of the pancreas is considered to be a pathognomonic sign.
F) Transmission of the virus is believed to be direct.
G) Control is by avoiding exposing susceptible trout to the virus. If the disease occurs, raising the water temperature to 15°C or more will minimize losses.


Channel Catfish Virus

A) Herpesvirus
B) Observed in fry or fingerling channel catfish (less than 10 gram weight) during the summer when water temperatures are above 22°C.
C) Clinically these fish usually show erratic swimming or spiralling followed by terminal lethargy. Mortality is very high.
D) Lesions:
1) Hemorrhage at the base of the fins and skins;
2) Ascites; exophthalmos; and pale gills;
3) Kidneys swollen and pale with hemorrhage;
4) Spleen is enlarged and dark red;
5) Gills usually pale;

E) Histopathology: Multifocal areas of necrosis and hemorrhage are observed in the posterior kidney, liver, intestines, and spleen.
F) Infection is direct with transmission of the virus in the water or feed. Piscivorous birds, snakes, or turtles may mechanically carry the virus from pond to pond. Transovarian transmission has not been conclusively demonstrated but is suspected. Survivors are persistently infected and become carriers for life.
G) Control of the disease is by sanitation, purchasing of virus free broodstock and lowering water temperature to less than 19°C during an outbreak to lessen the mortality.

Epithelioma papillosum (Fish Pox)

A) Herpesvirus cyprini
B) Non-fatal disease is observed in carp and other cyprinids
C) Lesions: Elevation of the epidermis with the formation of white to yellow plaques over the body of the fish. Healed lesions usually turn black.
D) Histopathology: There is epidermal hyperplasia with the epithelial cells occasionally demonstrating intranuclear inclusion bodies.
E) Transmission is unknown, however, it is probably direct.

Infectious Hematopoietic Necrosis (IHN)

A) Rhabdovirus
B) The disease is observed in fry of trout (rainbow) and salmon (chinook and sockeye) with mortality up to 100%.

C) Clinical signs and lesions:

1) Fish become lethargic or hyperactive.
2) The fish become dark in color.
3) Exophthalmus, abdominal distension, and fecal cast.
4) Hemorrhage on skin and viscera primarily at base of fins behind the skull and above the lateral line.
5) Anemia with pale gills.

D) Histopathology: There is prominent necrosis of hematopoietic tissue including melanomacrophages of the kidney, red pulp of the spleen and hepatic parenchyma. Necrosis of the submucosal eosinophilic granular cells is considered pathognomonic for IHN. (This lesion is observed in other systemic viral diseases.) Intranuclear and intracytoplasmic inclusions are occasionally observed in acinar and islet cells of pancreas.

E) The virus is transmitted by direct contact with infected survivors or by feeding contaminated feed. The virus is probably shed in contaminated semen and eggs. The disease is most severe at 10°C.

Spring Viremia of Carp (SVC) and Swim Bladder Infection virus (SBI)A) Caused by several subtypes of Rhabdovirus carpio.
B) Disease occurs in carp and other cyprinids.


C) Clinical Signs and Lesions:

1) Loss of coordination and equilibrium.
2) Exophthalmus and abdominal distension (ascites).
3) Inflamed and swollen vent.
4) Edema and hemorrhage in many organs.
5) In SBI see pronounced inflammation and hemorrhage of Swim-bladder.


D) Transmission: Virus shed in feces and found in contaminated eggs.

Infectious Pancreatic Necrosis (IPN)
A) Birnavirus
B) Affects most salmonids primarily rainbow trout and brook trout. IPN has also been implicated in disease among several nonsalmonid fish.
C) Clinical signs and lesions:
1) IPN is characterized by a sudden explosive outbreak with high mortality



2) Affected fish become dark and rotate their bodies while swimming.
3) Diseased fish usually have distended abdomens and exophthalmus.
4) The presence of a gelatinous material in the stomach and anterior intestine is highly suggestive of IPN; mucoid fecal casts are common.
5) Infected fish commonly have low hematocrits and hemorrhage in gut, primarily in the area of the pyloric ceca.

D) Histopathology:
Histologically, there is necrosis of the pancreatic acini, gut mucosa, and renal hematopoietic elements. A moderate inflammatory infiltrate is usually observed around the pancreatic acini. Hyalin degeneration of skeletal muscle is also observed.

Fish bioloGy

BIOLOGY OF FISH

Fish have some unique anatomical and physical characteristics that are different from mammals, however, they still possess the same organ systems that are present in other animals. All fish are poikilothermic and must be able to adapt to changes in water temperature. Fish live in a variety of temperatures ranging from less than 0øC to hot geothermal springs. Yet, each species of fish must live in its particular specific temperature range. Abrupt temperature changes can be lethal.
Organ systems of fish vary to some extent from that of mammals due to the aquatic environment they live in. The following are some of the important differences.

INTEGUMENT

Fish do not have a keratin layer over the epidermis. These animals are covered by a cuticle composed of mucus, mucopoly- saccharides, immunoglobins and free fatty acids. The epidermis is composed of a stratified squamous epithelium of variable thickness (4-20 cells thick). The outermost epidermal cells (Malpighian cell layer) retain the capacity to divide. Other cells present in the epidermis are goblet cells (responsible for secreting the cuticle), large eosinophilic club cells or alarm cells (present in most species of fish), eosinophilic granular cells (unknown function), leukocytes and macrophages.
The dermis is composed of an upper stratum spongiosum and a deeper stratum compactum. Numerous melanophores, xanthophores, and iridophores (give fish their silvery color) are observed scattered throughout the dermis. Scales are calcified plates originating in the dermis and covered by the epidermis. There are two types of scales: ctenoid scales and cycloid scales. Ctenoid scales of elasmobranchs have spicules extending from the external surface giving these fish a rough sandpaper-like texture. Cycloid scales of teleost fish have a smooth outer surface and are laid down in concentric rings which makes them useful in determining the age of some fish. Scales also represent a source of calcium for fish; some fish will utilize the calcium in the scales in preference to the calcium in their skeleton during times of starvation or prespawning activity.


RESPIRATORY

The gills consist of four holobranchs which form the sides of the pharynx. Each holobranch has two hemibranchs projecting from the gill arch. The hemibranch are composed of rows of long thin filament called primary lamella. The primary lamella have their surface area increased further by the secondary lamella that are semilunar folds over the dorsal and ventral surface. Gas exchange takes place at the level of the secondary lamella. These are lined by epithelial cells bounded by pillar cells. A thin endothelial lined vascular channel lies between the pillar cells and is the site of gas exchange, removal of nitrogenous waste and some electrolyte exchange.
The pseudobranch lies under the dorsal operculum. This organ is a gill arch with a single row of filaments. The function of the pseudobranch is unknown, however it is believed that this structure supplies highly oxygenated blood to the optic choroid and retina and may have thermoregulation and baroreceptor functions.

ENDOCRINE SYSTEM

- Adrenal Gland
There is no true adrenal gland present in most fish (exception is sculpins). The adrenal cortical tissue is represented by the interrenal cells. These cells are pale eosinophilic cuboidal cells associated with major blood vessels in the anterior kidney. Both glucocorticoid and mineralocorticoid are secreted.
The adrenal medullary cells (chromaffin cells) may vary in location. These cells are usually found with the sympathetic ganglia in clumps between the anterior kidney and spine or in the interrenal tissue.

- Thyroid Gland
The thyroid follicles are very similar to mammalian thyroid tissue. Thyroid follicles are distributed throughout the connective tissue of the pharyngeal area and may be observed around the eye, ventral aorta, hepatic veins and anterior kidney. It is important to realize that thyroid tissue can be widely distributed. Many times pathologist have erroneously considered this distribution of normal thyroid tissue to represent metastasis from a thyroid follicular cell tumor.
- Endocrine Pancreas
The endocrine pancreas is present in most fish as islet of Langerhans and is associated with the exocrine pancreas. In some species the islets are very large and may be grossly visible (Brockman bodies). During the spawning season the size and number of islet will increase in some fish. These should not be confused with an adenoma.

- Parathyroid Glands
The parathyroid glands are absent in fish, their function is taken over by othe

endocrine organs. (Corpuscles of stannius)

- Ultimobranchial Gland
This gland lies ventral to the esophagus in the transverse septum separating the heart from the abdominal cavity. This organ secretes calcitonin (lowers serum calcium levels) which acts with hypocalcin (secreted by the corpuscles of Stannius) to regulate calcium metabolism.
- Corpuscles of Stannius
These are islands of eosinophilic granular cells located in paired organs on the ventral surface of the kidney. This organ secretes a protein called hypocalcin (teleocalcin) which acts with calcitonin to regulate calcium metabolism.

- Urophysis
This is a neurosecretory organ found on the ventral aspect of the distal end of the spinal cord. These bodies are composed of unmyelinated axons terminating on a capillary wall. The function of the urophysis is unknown.

- Pineal Gland
The pineal gland is a light sensitive neuroendocrine structure which lies in the anterior brain and is a well vascularized organ. This gland secretes melatonin which may play a role in controlling reproduction, growth, and migration.

DIGESTIVE SYSTEM
The digestive system of fish is similar to the digestive tract of other animals. Carnivorous fish have short digestive tracts when compared to herbivorous fish. The stomach and intestines contain submucosal eosinophilic granular cells. The function of these cells is unknown. Some species of fish (Salmonids) have pyloric cecae which are occasionally confused with parasites. These ceca secrete the digestive enzymes required to digest some food. Fish without the pyloric cecae have digestive enzyme production in the liver and pancreas. It is not possible to divide the intestine into large and small intestine.The liver does not have the typical lobular architecture that is present in mammals. In many species of fish there are areas of exocrine pancreas (hepatopancreas) that are present near the small veins off the hepatic portal vein.The pancreas is scattered in the mesentery, primarily near the pylorus.

RETICULOENDOTHELIAL SYSTEM

Fish do not have lymph nodes. Phagocytic cells are present in the endothelial lining of the atrium of the heart and in the gill lamella. There are no phagocytic cells (Kupffer cells) in the liver. Melanomacrophage centers are present in the liver, kidney and spleen. Melanomacrophage centers increase in number during disease or stress.The fish thymus is the central lymphoid organ. This organ is located subcutaneously in the dorsal commissure of the operculum.
Fish have the ability to produce specific immunoglobins (IgM only) and have both delayed and immediate hypersensitivity. Fish have the ability to produce virus neutralizing, agglutinating, and precipitating antibodies. Both B and T lymphocytes are present.

CARDIOVASCULAR SYSTEM

The heart is composed of two chambers; one ventricle and one atrium. Some authors also describe the sinus venosus as the third chamber and bulbus arteriosus as the fourth chamber. Blood flows from the heart to the ventral aorta to the afferent branchial arteries to the gills for oxygenation and returns via the efferent arteries to the dorsal aorta. The dorsal aorta then carries the oxygenated blood to the body. Some oxygenated blood also leaves the dorsal aorta and goes to the pseudobranch to be highly oxygenated and then is sent to the retina which has a high oxygen demand.

URINARY SYSTEM

The kidneys of fish develop from the pronephros and mesonephros. The function of the kidney is osmoregulation. In freshwater fish, the kidney saves ions and excretes water. In saltwater fish, the kidney excretes ions and conserves water. The majority of nitrogenous waste is excreted through the gills. The other function of the kidney is hematopoiesis with hematopoietic tissue located in the interstitium of the kidney. This function is primarily in the anterior kidney but can be found throughout the entire kidney.

SPECIAL SENSE ORGANS

- Lateral line system
There are two types of lateral line organs. These are the superficial neuromast and the two lateral line canal organs. There are two types of superficial neuromast, these are located in pits in the epidermis located primarily on the head. Their function is not completely known but is believed to aid in movement and orientation.
The second lateral line organ is the lateral line canal system which runs the entire length of the fish with continuous extensions over the head. This organ is sensitive to hydrostatic stimuli and sound.

Jenis Penyakit Pada Ikan Budidaya Air Payau

JENIS PENYAKIT PADA IKAN (FINFISH) BUDIDAYA AIR PAYAU


Kasus penyakit yang paling banyak pada ikan bersirip (finfish) dijumpai pada budidaya ikan kerapu. Sedangkan kasus penyakit pada ikan bandeng selama ini jarang ditemukan.
Penyakit bakterial
Jenis penyakit bakterial yang ditemukan pada ikan kerapu, diantaranya adalah penyakit borok pangkal strip ekor (Gambar 1), dan penyakit mulut merah. Hasil isolasi dan identifikasi bakteri ditemukan beberapa jenis bakteri yang diduga berkaitan erat dengan kasus penyakit bakterial, yaitu Vibrio alginolyticus, V algosus, V anguillarum dan V fuscus. Diantara jenis bakteri tersebut bakteri V alginolyticus dan V fuscus merupakan jenis yang sangat patogen pada ikan kerapu tikus.
1. Vibrio alginolyticus
Vibrio alginolyticus dicirikan dengan pertumbuhannya yang bersifat swarm (Gambar 2) pada media padat non selektif. Ciri lain adalah gram negatif, motil, bentuk batang, fermentasi glukosa, laktosa, sukrosa dan maltosa, membentuk kolom berukuran 0.8-1.2 cm yang berwarna kuning pada media TCBS. Bakteri ini merupakan jenis bakteri yang paling patogen pada ikan kerapu tikus dibandingkan jenis bakteri lainnya. Nilai konsentrasi letal median (LC50) adalah sebesar 106.6 pada ikan dengan berat antara 5-10 gram. Kematian masal pada benih diduga disebabkan oleh infeksi bakteri V alginolyticus. Pengendalian penyakit dapat dilakukan dengan penggunaan berbagai jenis antibiotika seperti Chloramfenikol, eritromisina dan oksitetrasiklin. Sifat lain yang tidak kalah penting adalah sifat proteolitik yang berkaitan dengan mekanisme infeksi bakteri.
2. Vibrio anguillarum
Dibandingkan dengan V alginolyticus, V anguillarum merupakan spesies yang kurang patogen terhadap ikan air payau. Pada uji patogenisitas ikan kerapu tikus ukuran 5 gram yang diinfeksi bakteri dengan kepadatan tinggi hingga 108 CFU/ikan hanya mengakibatkan mortalitas 20%.
Diagnosis penyakit dapat dilakukan dengan melakukan isolasi dan identifikasi bakteri. Penumbuhan bakteri pada media selektif TCBS akan didapatkan koloni yang kekuningan dengan ukuran yang hampir sama dengan koloni V alginolyticus akan tetapi bakteri ini tidak tumbuh swarm pada media padat non-selektif seperti NA.
Penyakit protozoa

1. Cryptocaryonosis
Penyakit ini sering ditemukan pada ikan kerapu bebek dan macan, dengan tanda ikan yang tersering terlihat bercak putih. Stadia parasit yang menginfeksi ikan dan menimbulkan penyakit adalah disebut trophont berbentuk seperti kantong atau genta (Gambar 3) berukuran antara 0.3-0.5 mm, dan dilengkapi dengan silia.
Tanda klinis ikan yang terserang adalah ikan seperti ada gangguan pernafasan, bercak putih pada kulit, produksi mukus yang berlebihan, kadang disertai dengan hemoragi, kehilangan nafsu makan sehingga ikan menjadi kurus. Erosi (borok) dapat terjadi karena infeksi sekunder dari bakteri.
Diagnosis dapat dilakukan dengan melihat gejala seperti adanya bercak putih, tetapi untuk lebih memantapkan (diagnosis definitif) perlu dilakukan pengamatan secara mikroskopis dengan cara memotong insang, mengerok dari lendir.
Serangan penyakit dapat diatasi dengan penjagaan kualitas air. Perlakuan bahan kimia pengendali parasit dapat dilakukan seperti perendaman dalam larutan formalin 25 ppm, perendaman ikan dalam air bersalinitas 8 ppt selama beberapa jam dan memindahkan ikan yang sudah diperlakukan ke dalam wadah barn bebas parasit.

2. Infestasi Trichodina
Penempelan Trichodina (Gambar 4) pada tubuh ikan sebenarnya hanya sebagai tempat pelekatan (substrat), sementara parasit ini mengambil partikel organik dan bakteri yang menempel di kulit ikan. Tetapi karena pelekatan yang kuat dan terdapatnya kait pada cakram, mengakibatkan seringkali timbul luka, terutama pada benih dan ikan muda. Pelekatan pada insang juga seringkali disertai luka dan sering ditemukan set darah merah dalam vakuola makanan Trichodina. Pada kondisi ini maka Trichodina merupakan ektoparasit sejati.
Trichodina yang merupakan ektoparasit pada ikan air laut mempakan spesies yang bersifat sebetulnya lebih bersifat komensal daripada ektoparasit. Trichodina spp. yang didapatkan pada ikan air payau merupakan spesies yang memiliki toleransi yang luas terhadap kisaran salinitas. Trichodina yang menempel di insang umunmya berukuran lebih kecil dibandingkan yang hidup di kulit, contohnya adalah Trichodinella.
Ikan yang terserang Trichodina biasanya warna tubuhnya terlihat pucat, produksi lendir yang berlebihan dan terlihat kurus. Diagnosis dapat dilakukan dengan cara melakukan pengerokan (scraping) pada kulit, atau mengambil lembaran insang dan melakukan pemeriksaan secara mikroskopis.
Pencegahan terhadap wabah penyakit adalah dengan cara pengendalian kualitas lingkungan, karena mewabahnya penyakit berkaitan dengan rendahnya kualitas lingkungan. Perlakuan terhadap ikan yang terinfeksi oleh parasit adalah dengan cara perendaman dalam larutan formalin 200-300 ppm.

3. Caligus sp., parasit golongan Crustacea
Parasit jenis ini sering, ditemukan baik pada induk ikan maupun di tambak. Penempelan ektoparasit ini dapat menimbulkan luka, dan akan lebih parah lagi karena ikan yang terinfeksi dengan parasit sering menggosok-gosokkan tubuhnya ke dinding bak atau substrat keras lainnya. Timbulnya luka akan diikuti dengan infeksi bakteri.
Caligus sp. berukuran cukup besar sehingga dapat diamati dengan tanpa bantuan mikroskop. Perlakuan ikan terserang parasit cukup mudah, yaitu hanya merendamnya dalam air tawar selama beberapa menit. Perlakuan dengan formalin 200-250 ppm juga cukup efektif. Penggunaan bahan seperti Triclorvon (Dyvon 95 SP) hiingga 2 ppm dapat mematikan parasit.

Sumber : Balai Besar Pengembangan Budidaya Air Payau Jepara, 2004


Vibrio Infections of Fish 1

Peggy A. Reed and Ruth Francis-Floyd2
Vibrio infections usually occur in fish from marine and estuarine environments, and have been reported throughout the world. Occasionally, vibriosis is reported in freshwater fish. The disease can cause significant mortality (=>50%) in fish culture facilities once an outbreak is in progress. Common names for Vibrio infections of fish include "red pest" of eels, "salt-water furunculosis", "red boil", and "pike pest". Vibrio infections can spread rapidly when fish are confined in heavily stocked, commercial systems and morbidity may reach 100% in affected facilities.
The disease is caused by gram negative bacteria in the family Vibrionaceae. This group of bacteria includes two important genera which can be significant fish pathogens. The genus Aeromonas includes several species which are important pathogens of freshwater fish, although they occasionally cause disease in marine species (see IFAS Extension Fact Sheet FA-14 for more information on Aeromonas infections of fish). Bacteria in the genus Vibrio are important pathogens of marine and brackish water fish, although they occasionally are reported in freshwater species. Seven species of Vibrio have been associated with disease in fish:
• V. anguillarum (isolated most commonly from marine and brackish water fish);
• V. ordalli (an atypical strain of
• V. anguillarum , sometimes referred to as Biotype 2);
• V. damsela (isolated from damsel fish);
• V. carchariae (isolated from sharks);
• V. vulnificus (reported in Japanese eels); and
• V. alginolyticus (reported from cultured seabream in Israel).
A new, extremely pathogenic Vibrio infection of cold-water marine fish (i.e., salmon) is caused by V. salmonicida and is referred to as "cold-water vibrio" or "hitra" disease. Cold-water vibrio has not been reported in warm-water fish and will not be discussed further in this publication.
Vibrio species are also known to cause disease in humans, most often following the consumption of contaminated shellfish. Most serious illness is usually limited to individuals with a suppressed immune system, such as those with liver disease or Acquired Immune Deficiency Syndrome (AIDS). However, it is always wise to wear gloves while examining sick fish, and to wash your hands thoroughly with a bactericidal soap afterwards.
Signs of Infections
The signs of vibriosis are similar to many other bacterial diseases of fish. They usually start with lethargy and a loss of appetite. As the disease progresses, the skin may become discolored, red and necrotic (dead). Boil-like sores may appear on the body, occasionally breaking through the skin surface resulting in large, open sores. Bloody blotches (erythema) are common around the fins and mouth. When the disease becomes systemic, it can cause exopthalmia ("pop-eye"), and the gut and rectum may be bloody and filled with fluid. It should be noted that all of these "signs" can be caused by other bacterial diseases, and are not proof of a Vibrio infection.
Diagnosis
Although a Vibrio infection can be suspected given certain case histories and clinical signs, proper diagnosis requires isolation of the bacteria and its identification. If you are unable to perform these tasks yourself, live, diseased fish should be delivered to a diagnostic laboratory familiar with fish diseases to confirm the infection, identify the species of Vibrio , and perform an antibiotic sensitivity test. Contact your county extension agent for assistance on where and how to submit samples for diagnostic services.
For those who are capable of culturing bacteria, Vibrio spp. prefer a blood agar supplemented with 3% salt, but enriched media such as trypticase soy agar with 5% ovine blood is adequate for initial isolation. Vibrio spp. can be differentiated from closely related bacteria by its specific sensitivity to Novobiocin and 0/129, two commercially available vibriostatic agents. Despite the unique "comma-shape" of Vibrio bacteria, microscopic examination of infected tissues cannot be used in place of culture and isolation techniques.
Transmission
The precise route of Vibrio infection is unclear, but oral transmission is suspected. It is possible to isolate Vibrio spp. from the intestinal tract of clinically normal fish. Under certain conditions, the bacteria may be capable of crossing the intestinal wall, resulting in systemic disease. Once an outbreak is in progress, the number of infectious particles in the environment rises dramatically, increasing the chance that exposed fish will get sick.

Management
In confined, heavily stocked, commercial systems, Vibrio disease outbreaks can proceed rapidly. Therefore, prevention is essential to any management scheme. As Vibrio species are believed to be opportunistic, conditions which favor a disease outbreak are often caused by environmental stress which can be avoided. Poor nutrition or water quality, improper handling, overcrowding, and the presence of other disease-causing agents will all increase your fish's chances of contracting a Vibrio infection. Parasites are of special concern, as they often cause damage to fish tissue, creating an ideal location for Vibrio infections to begin. Chemical treatments, including the use of copper compounds, can be harsh on fish and have been reported to precipitate Vibrio disease outbreaks.
Quarantine of new fish and good sanitation practices should be used at all times, and will minimize the spread of Vibrio infection from infected to uninfected fish, should a disease outbreak occur. New fish should always be kept away from existing fish. Tanks and culture facilities should be kept clean and free of any unnecessary wastes.

Treatment
Before any treatment with antibiotics, a thorough investigation of water quality and husbandry practices should be conducted. Removal of underlying problems is essential to successful resolution of the problem. Occasionally, removal of contributing factors (i.e., poor water quality) will be all that is required to control the infection, but in most cases it is prudent to treat an active Vibrio outbreak with antibiotic therapy.
The selection of an antibiotic should be based on results of an in vitro sensitivity test. There are two antibiotics which have been approved by the Food and Drug Administration (FDA) for use in food fish (catfish and salmonids) in the United States. Terramycin contains the antibiotic oxytetracycline. It is sold for fish in a sinking feed and should be fed for 10 days. Fish which have been fed Terramycin should not be eaten for at least 21 days following treatment (the legal withdrawal time) to ensure complete elimination of drug residue from edible tissue. Romet is a potentiated sulfonamide which contains two drugs, sulfadimethoxine and ormetoprim. It is sold for fish in a floating feed and should be fed for 5 days. The withdrawal time of Romet for catfish is only 3 days because the drug is bound in the skin of the fish which is removed when catfish are cleaned. In salmonids, however, the withdrawal time is 6 weeks because the fish are not skinned during processing. Either drug will be effective if the strain of Vibrio is sensitive to it and if sick fish ingest enough medication to maintain the drug in the bloodstream throughout the treatment period.
In pet fish, the traditional treatment for bacterial disease has been the addition of antibiotics to tank water. This practice should only be pursued as a last resort. Antibiotics should be delivered to fish in medicated feeds or by injection. Flake foods which contain Terramycin or Romet are commercially available through pet retail outlets for use in aquarium fish. Because there is no FDA-approved antibiotic available for use in pet fish, veterinary supervision of antibiotic therapy is recommended. If fish do not respond to antibiotic therapy within 48 hours a sample of sick fish and water should be sent to a fish disease diagnostic laboratory to confirm the original diagnosis and determine whether additional problems, such as parasitism, may also be present.

Vaccination
Commercial vaccines are available to prevent vibriosis in salmonids. In the United States, animal vaccines are regulated by the United States Department of Agriculture (USDA). In species other than salmonids, veterinary supervision will be required for vaccine access and use. Vaccinated fish appear to grow and survive better than their unvaccinated counterparts, however the exact nature of the immunity provided is not clear. Most commercial products are bivalent vaccines; this means that they provide protection to two different organisms, in this case V. anguillarum and V. ordalli . Vaccines are usually administered to the fish by immersion, although injectable and oral products are also available. Efficacy of oral vaccines has not been as good as injectable or immersion products.Vaccines made from sonicated, heat-killed bacteria are also available and effective.

Summary
Vibriosis is primarily a disease of marine and estuarine fish, both in commercial production systems and natural waters throughout the world. Stress and overcrowding often are associated with disease outbreak. Although a presumptive diagnosis can be made based on history and examination of the fish, a definitive diagnosis can only be made following bacterial isolation and identification. Antibiotic therapy should be based on results of in vitro sensitivity tests. Two antibiotics, Terramycin (an oxytetracycline compound) and Romet (a potentiated sulfonamide) have been approved by the Food and Drug Administration for use in catfish and salmonids. Vaccination, which can be administered by injection, immersion, or orally, is used by the salmon industry to minimize the impact of vibriosis.


About half of new marine vibrio bacteria discovered in the last five years, can kill fish and crustacea, according to researchers at Heriot-Watt University in Edinburgh.

The most common disease of vibrios is cholera, which has caused millions of cases of illness and fatality in humans. Recent interest in this genus of bacteria has led to the discovery of many new species, especially from seawater and marine animals.

New species have been found in a wide range of marine environments, including corals, sediments and rotifers. For example, Vibrio coralliilyticus has recently been described as a new cause of disease in coral.

Professor Brian Austin of Heriot-Watt University said that his research demonstrates that some of these new species are similar to existing fish and shellfish pathogens. The new species, Vibrio brasiliensis, seems to be related to Vibrio tubiashii, which has long been known to cause disease in oysters.

Professor Austin comments: "Having observed this, the question arose about whether any of these new species could have implications to the health of marine animals. The answer was that around half of the new species killed fish in laboratory conditions. Our research shows that marine vibrios could cause disease to fish and crustaceans. In some cases, only 100 bacterial cells from the pathogens were capable of causing disease. This means that the bacteria are extremely aggressive and could pose a great risk to sea animals, as disease is often caused by enzymes produced by bacteria."

It is not yet clear to what extent these new vibrios affect marine animals in the wild. The next thrust of the work by Professor Austin and his team is to devise methods to minimize the risk of these bacteria to animals and the environment.

1. Pathogenicity of vibrios to rainbow trout (Oncorhynchus mykiss, Walbaum) and Artemia nauplii Brian Austin, Dawn Austin, Rowan Sutherland, Fabiano Thompson, Jean Swings

2.The species studied were: Vibrio brasiliensis, Vibrio coralliilyticus, Vibrio ezurae, Vibrio fortis, Vibrio kanaloaei, Vibrio neptunius and Vibrio rotiferianus

**

Vibrio bacteria could be a risk to fish as well as humans
Press release based on a recent article published by Environmental Microbiology
About half of new marine vibrio bacteria discovered in the last five years, can kill fish and crustacea, according to researchers at Heriot-Watt University in Edinburgh.
The most common disease of vibrios is cholera, which has caused millions of cases of illness and fatality in humans. Recent interest in this genus of bacteria has led to the discovery of many new species, especially from seawater and marine animals.
New species have been found in a wide range of marine environments, including corals, sediments and rotifers. For example, Vibrio coralliilyticus has recently been described as a new cause of disease in coral.
Professor Brian Austin of Heriot-Watt University said that his research demonstrates that some of these new species are similar to existing fish and shellfish pathogens. The new species, Vibrio brasiliensis, seems to be related to Vibrio tubiashii, which has long been known to cause disease in oysters.
Professor Austin comments: "Having observed this, the question arose about whether any of these new species could have implications to the health of marine animals. The answer was that around half of the new species killed fish in laboratory conditions. Our research shows that marine vibrios could cause disease to fish and crustaceans. In some cases, only 100 bacterial cells from the pathogens were capable of causing disease. This means that the bacteria are extremely aggressive and could pose a great risk to sea animals, as disease is often caused by enzymes produced by bacteria." It is not yet clear to what extent these new vibrios affect marine animals in the wild. The next thrust of the work by Professor Austin and his team is to devise methods to minimize the risk of these bacteria to animals and the environment.

Notes::

1. Pathogenicity of vibrios to rainbow trout (Oncorhynchus mykiss, Walbaum) and Artemia nauplii Brian Austin, Dawn Austin, Rowan Sutherland, Fabiano Thompson, Jean Swings
2.The species studied were: Vibrio brasiliensis, Vibrio coralliilyticus, Vibrio ezurae, Vibrio fortis, Vibrio kanaloaei, Vibrio neptunius and Vibrio rotiferianus.


JENIS PENYAKIT

1. Penyakit pada kulit
Kulit ikan menunjukkan warna pucat dan berlendir. Tanda ini terlihat jelas pada ikan yang berwarna gelap. Penyakit yang disebabkan oleh jamur menimbulkan bercak-bercak warna kelabu, putih atau kehitam-hitaman pada kulit ikan. Ikan yang menderita penyakit kulit kadang-kadang menggosok-gosokkan badannya pada suatu benda di dalam air.

2. Penyakit pada insang
Ikan terlihat sulit bernafas. Tutup insang mengembang dan lembaranlembaran insang pucat. Pada lembaran-lembaran insang terlihat bintikmerah yang disebabkan oleh pendarahan kecil (peradangan). Jika terdapat bintik-bintik putih pada insang, hal ini diebabkan oleh parasit kecil yang menempel pada tempat tersebut.
3. Penyakit pada organ (alat-alat dalam)
Perut ikan membengkak dengan sisik-sisik ikan berdiri (penyakit dropsy),dapat juga sebaliknya, perut menjadi sangat kurus. Kotoran ikan berdarah, menandakan adanya radang usus. Penyakit pada gelembung renang, menyebabkan ikan berenang terjungkir balik karena terganggunya keseimbangan badan.
PENYEBAB PENYAKIT

1) Non Parasit

a. Faktor-faktor kimia dan fisika, antara lain:
o Perubahan salinitas air secara mendadak;
o pH yang terlalu rendah (air asam), dan pH yang terlalu tinggi (air basa/alkalis);
o Kekurangan oksigen dalam air;
o Zat beracun, pestisida (insektisida, herbisida dan sebagainya);
o Perubahan suhu air yang mendadak;
o Kerusakan mekanis (luka-luka);
o Perairan terkena polusi.
o b. Makanan yang tidak baik :
o Kekurangan vitamin dan komposisi gizi yang buruk;
o Bahan makanan yang busuk dan mengandung kuman-kuman.
c. Bentuk fisik dan kelainan-kelainan tubuh yang disebabkan oleh keturunan.

d. Stres
Stres yang terjadi pada ikan berkaitan dengan timbulnya penyakit pada ikan tersebut. Stres merupakan suatu rangsangan yang menaikkan batas keseimbangan psikologi dalam diri ikan terhadap lingkungannya. Biasanya stres pada ikan diakibatkan perubahan lingkungan akibat beberapa hal atau perlakuan misalnya akibat pengangkutan/transportasi
ikan-ikan yang dimasukkan ke dalam jaring apung di laut dari tempat pengangkutan biasanya akan mengalami shock, berhenti makan dan mengalami pelemahan daya tahan terhadap penyakit.
e. Kepadatan Ikan
Kepadatan ikan yang melebihi daya dukung perairan (carrying capacity) akan menimbulkan persaingan antar ikan tinggi, oksigen terlarut menjadi rendah dan sisa metabolisme seperti ammonia akan meningkat sehingga dapat menimbulkan stres dan merupakan penyebab timbulnya serangan penyakit.

2) Parasit (Pathogen)
1. Pengertian :
Parasit atau panthogen adalah organisme dalam bentuk hewan atau tumbuh-tumbuhan atas pengorbanan dari induk emangnya (hewan atau tumbuh-tumbuhan lain). Parasit dapat berkembang dan menyebabkan infeksi yang dapat menularkan penyakit itu sendiri.
2. Penyebab penyakit :
o Crustacea/udang renik
o Protozoa
o Jamur
o Bakteri
o Virus
4. PENGOBATAN PENYAKIT
1) Non parasit
a. Pencegahan penyakit yang ditimbulkan oleh penyakit non parasit adalah :
• Lingkungan harus baik
Lingkungan, terutama sifat fisika, kimia biologi perairan akan sangat mempengaruhi keseimbangan antara ikan sebagai inang dan organisme penyebab penyakit. Lingkungan yang baik akan meningkatkan daya tahan ikan, sedangkan lingkungan yang kurang baik akan menyebabkan ikan mudah stres dan menurunkan daya tahan tubuh terhadap serangan penyakit non parasit.
• Kepadatan ikan yang seimbang
Kepadatan ikan yang melebihi daya dukung perairan (carrying capacity) akan menimbulkan persaingan antar ikan tinggi, oksigen terlarut menjadi rendah dan sisa metabolisme seperti amoniak akan meningkat seperti amoniak akan meningkat sehingga dapat menimbulkan stres dan merupakan penyebab timbulnya penyakit.
• Makanan yang seimbang
Pemberian makanan yang kurang bermutu dapat menyebabkan kekurangan vitamin yang diikuti oleh pertumbuhan yang lambat atau menurunnya daya tahan ikan sehingga mudah untuk terserang suatu penyakit, disamping tingkat pemberian pakan dan kualitas makanan juga akan mempengaruhi sistem kekebalan.
b. Pengobatan yang bisa dilakukan :
• Melalui suntikan dengan antibiotika.
• Melalui makanan.
• Perendaman.
• Penyemprotan dengan tekanan tinggi.
2) Parasit
Beberapa macam parasit ikan dan pengobatannya :
a. Crustacea
Beberapa jenis crustacea yang sudah diketahui sebagai parasit ikan diantaranya adalah copepoda dan isopoda. Salah satu jenis copepoda ialah : Argasilus sp didapati biasa menyerang pada ikan laut yang dipelihara. Untuk jenis isopoda yang biasa terdapat dan merupakan parasit ikan adalah Nirocila sp.
Nirocila sp menyerang berbagai jenis ikan laut yang dipelihara, terutama terhadap ikan berukuran di atas 50 gram. Binatang ini mempunyai duri pengait pada kakinya sehingga dapat menempel dengan kuat pada insang atau di bagian sisi tubuh ikan yang
diserang. Serangan pada bagian insang ini bisa mengakibatkan borok karena jaringan daging pada insang dimakan oleh parasit tersebut.
Nirocila sp tergolong binatang vivaparous. Telur yang dihasilkan dierami dan anak yang menetas tumbuh dan berkembang di dalam kantong yang terletak di bawah perutnya.
Nirocila muda kemudian dilepaskan dan berenang bebas yang kemudian dapat menginfeksi ikan yang lain. Nirocila sp adalah protandrous di mana pada waktu muda mereka berkelamin jantan dan berubah menjadi betina pada waktu dewasa (matang).
Nirocila sp tahan terhadap kebanyakan pestisida seperti Dipterex, Matathion dan Hhyrethroids syntetic. Organophospat DDVP cukup aman dan efektif untuk pemberantasan parasit ini, namun jarang terdapat dalam bentuk yang masih murni.
Pengobatan dan pencegahan
Untuk mengatasi serangan parasit ini disarankan memakai formalin dengan cara sbb :
• Angkat jaring apung dan simpanlah ikan-ikan yang terserang di dalam bak/tank.
• Semprotkan formalin 1% ke jaring tersebut.
• Tambahkan formalin (200 ppm) ke dalam bak sampai parasit tersebut lepas dari tubuh ikan dan
• Keluarkan parasit-parasit tersebut dan musnahkan.
Biasanya serangan Nirocila sp dewasa (ukuran 2 - 3 cm) jarang berakibat serius. Serangan parasit dewasa mudah terlihat sewaktu dilakukan grading, sehingga dengan mudah dapat diambil dengan tangan untuk kemudian dimusnahkan.
b. Cacing Pipih
Dectylogyrus sp kadang-kadang ditemui menyerang ikan laut. Yang paling sering ditemukan menyerang ikan laut adalah Diplectanum sp. Bentuk parasit ini adalah sbb : mempunyai dua buah mata, ada alat penghisap (sucker) pada bagian depan dan belakang. Bagian belakang berbentuk seperti martil dengan bentuk seperti jangkar pada tiap ujungnya, bagian dalam perut seperti usus dan alat kelamin jelas terlihat. Parasit ini mempunyai panjang antara 0,5 - 1,0 dan memangsa sel-sel epithel insang ikan yang diserang.
Ikan yang terserang parasit ini atau jenis-jenis parasit lain yang menyerang insang cenderung untuk berenang ke arah air yang berarus kuat atau berenang miring di mana terlihat berbaring dengan insang terbuka lebar dan bergerak cepat. Biasanya serangan parasit ini sering bersamaan pula dengan serangan bakteri vibriosis. Insang ikan yang terserang kelihatan pucat dan mengeluarkan lendir yang berlebihan seperti pada penyakit cryptocoryoniasis. Apabila kondisinya sudah sedemikian parah, pengobatan akan percuma.
Pencegahan dan pengobatan
Pengobatan harus dilakukan secepatnya pada saat ikan kelihatan mulai terserang penyakit ini, dengan cara sbb :
• Menggunakan formalin 200 ppm selama 1/2 sampai 1 jam dengan aerasi yang kuat, ulangi sampai 3 hari.
• Menggunakan formalin 25 ppm dan malachite green 0,15 ppm selama semalam perendaman.
• Menggunakan acriflavina 10 ppm 1 jam atau 100 ppm dicelupkan selama 1 menit.
• Menggunakan dipterex 20 ppm selama 1 jam.
• Menggunakan air tawar murni selama 1 jam (hanya untuk Kakap Putih dan Kerapu Lumpur).
c. Protozoa
Protozoa merupakan pathogen yang paling utama bagi usaha budidaya laut. Protozoa merupakan jazad renik bersel satu dengan ukuran yang bervariasi antara 10 - 500 mikron. Parasit protozoa umumnya mempunyai bulu/cilia di sekeliling tubuhnya. Parasit pada budidaya ikan laut yang disebabkan oleh protozoa dapat digolongkan menjadi 3 jenis, yaitu : Cryptocaryoniasis, Brooklynelliasis dan Trichadiniasis.
- Cryptocaryoniasis
Penyakit ini paling umum dijumpai pada budidaya laut yang disebabkan oleh protozoa. Organisme penyebabnya adalah Cryptocaryon irritans Brown, dijumpai secara luas seperti halnya Ichthyophthirius multifilis yang terdapat di air tawar. Pada stadium belum dewasa binatang ini cenderung berbentuk seperti buah pear. Bagian mulut (Cryclostomum) terlihat seperti pada ganbar 5 dimana terlihat sedang memangsa sel daging ikan.
Pemangsaan yang terus menerus kadang-kadang menyebabkan kerusakan pada kulit atau insang. Stadia "trophont" berbentuk seperti bola dengan garis tengah sekitar 300 mikron, terbungkus oleh bulu-bulu
halus/cilia.
Ikan Kerapu Lumpur dapat terserang penyakit bintik putih seperti terserang Ichtyophthirius multifilis. Bintik putih terlihat berbentuk titik yang masuk cukup dalam. Dalam hal-hal tertentu di mana serangan penyakit ini ditunggangi oleh serangan bakteri maka akan timbul borok pada bagian yang terserang.
Ikan Kakap dan jenis ikan lain yang bersisik besar jarang terlihat bahwa tersebut terserang penyakti bintik putih. Ikan-ikan tersebut akan kehilangan nafsu makan, matanya membengkak, sisik-sisiknya lepas, kadang terjadi pendarahan pada kulitnya dan terjadi pembusukan bagian sirip akibat terinfeksi bakteri/infeksi sekunder.
Pada ikan Lutjanus (jenis Goden Snaper) kepala merupakan bagian yang paling rawan terhadap serangan parasit ini, yang kadang sampai sisik pada kepala bagian atas dan tutup insang mengelupas yang kemudian terlihat botak. Insang pada ikan yang terserang parasit ini akan rusak dan tidak berfungsi. Keluarnya lendir yang berlebihan biaanya tidak sehebat seperti pada serangan parasit Diplectanum sp.
Penyakit yang paling sering dijumpai pada ikan-ikan dan sangat susah diberantas ini sesebabkan oleh protozoa yang bersarang pada lapisan lendir kulit dan sirip ikan, serata merusak lapisan insang. Binatang yang sangat kecil dan tidak bisa dilihat oleh mata biasa ini, pada selaput ikan bergerombol sampai berpuluh-puluh bahkan beratus-ratus jumlahnya, hingga dapat terlihat sebagai bintik-bintik putih. Karena itu biasa disebut White spot.
Protozoa ini merusak sel-sel lendir ikan, dan dapat menyebabkan pendarahan, yang sering terlihat pada sirip dan insang ikan. Siklus hidup parasit ini sangat penting untuk diketahui, oleh karena itu segala cara pemberantasannya, pada dasarnya ialah memutuskan rantai kehidupan.
Sesudah 8 hari hidup pada ikan parasit ini sudah cukup dewasa untuk melangsungkan diri dari tubuh ikan, dan melayang-layang dalam air untuk beberapa saat lamanya. Kemudian ia melekatkan diri pada suatu benda, batu-batu, tumbuh-tumbuhan, gangang, dan sebagainya serta membentuk suatu lapisan kulit yang terlihat sebagai lendir. Bentuk demikian disebut cyste. Parasit ini dalam cyste membelah diri.
Dalam waktu 5 jam (lamanya tergantung suhu), terbentuklah beribu-ribu protozoa kecil-kecil. Kemudian dinding cyste itu pecah, lalu berhamburlah anak-anak parasit tersebut, melayang-layang dalam air, siap untuk menyerang ikan. Apabila dalam waktu 48 jam mereka tidak dapat menemukan ikan-ikan untuk ditempelinya maka anak-anak parasit itu akan mati. Jika ada ikan, mereka segera menempel dan tumbuh pada selaput lendir ikan.
Pada selaput lendir ikan, parasit protozoa ini hidup terbungkus oleh selaput sel lendir. Obat-obat pemberantas tidak dapat meresap kedalam parasit dalam keadaan tersebut, tanpa merusak selaput lendir ikan yang bersangkutan juga. Karena itu fase pre cyste, adalah fase yang mudah dikenai obat tanpa merusak ikan yang bersangkutan. Demikian juga cyste ketika benih parasit ini sudah keluar dari cyste.Sedangkan pada fase cyste, penyakit ini juga tidak tertembus oleh obat, karena berdinding lendir.
Terhadap penyakit ini tindakan yang lebih penting ialah pencegahan. Hal ini dilakukan dengan menciptakan suasana kesegaran dan kesehatan bagi ikan, sehingga ikan mempunyai daya tahan yang besar terhadap penyakit ini. Caranya ialah dengan memilih lokasi di mana air dapat selalu berganti lewat arus yang cukup.
Pencegahan dan pengobatan
Penanggulangan parasit ini cukup sulit. Stadia tomont berbentuk kista sangat tahan terhadap obat-obatan, sedangkan stadia trophonts seringkali masuk cukup dalam ke jaring daging ikan. Namun demikian perlakuan seperti tersebut di bawah ini dan telah banyak memberikan hasil yaitu :
• Celupkan ke dalam formalin 200 ppm selama 1/2 sampai 1 jam tergantung kepada daya tahan ikan.
• Celupkan ke dalam formalin 100 ppm dan acriflavin 10 ppm selama 1 jam.
• Celupkan dalam campuran formalin 25 ppm dan malachite green 0,15 ppm selama 12 jam.
• Menggunakan nitrofurazone 30 ppm selama 12 jam.
• Menggunakan methyllene blue 0,1 ppm selama setengah jam.
• Menggunakan air tawar murni selama 1 jam (hanya untuk ikan kakap dan kerapu lumpur).
Perlakuan tersebut diulangi 2 sampai 3 kali. Pengobatan juga dapat dilakukan dengan percampuran obat dalam ransum makanan, yaitu menggunakan metronidozone 5 gram untuk setiap kilogram makanan selama 10 hari.
Berdasarkan hasil percobaan, gejala penyakit cryptocaryoniasis akan terlihat dalam waktu 5 hari setelah ikan sehat diolesi insang dari ikan yang sakit. Tindakan yang perlu diambil untuk menanggulangi penyakit ini adalah sebagai berikut :
• Isolasi ikan-ikan yan ternyata sakit khususnya benih/gelondongan sejauh mungkin dari ikan-ikan yang sehat.
• Ambil ikan-ikan yang mati atau sakit parah dari keramba untuk kemudian dimusnahkan.
• Lakukan pengobatan sedini mungkin (begitu terlihat tanda-tanda ada ikan yang terserang penyakit ini) untuk memotong siklus hidup penyakit ini dan jangan sampai menjadi stadia kista serta terbentuknya tomite (stadia muda dan berenang bebas dari Cryptocaryon irritans).
- Brooklynelliasis
Penyakit ini disebabkan oleh Brooklynela sp, suatu protozoa berbentuk seperti kacang mirip dengan Chilodonella sp. mudah dikenal dengan adanya bulu rambut (cilia) yang panjang, sebuah macronucleus dan kantong berbentuk oval yang terlihat jelas. Brooklynela sp irritans, namun jenis ikan yang bisa terserang lebih sedikit.
Parasit ini dijumpai di bagian insang dan kulit dari ikan yang terserang.Tanda-tandanya penyakit yang ditimbulkan sama dengan penyerangan Cryptocaryon irritans, hanya saja jarang terjadi kerusakan kulit ikan yang terserang. Luka yang ditimbulkannya lebih tersebar dan terjadi pendarahan pada kulit bagian dalam.
Pendarahan ini kemungkinan disebabkan oleh kesengajaan ikan menggesek-gesekkan badannya ke jaring atau wadah budidaya lainnya yang diakibatkan gatal akibat serangan parasit ini pada bagian kulit.
Pencegahan dan pengobatan
Pemberantasan parasit ini dapat dilakukan seperti pada serangan parasit Cryptocaryon irritans. Keberhasilan upaya pemberantasan dapat dilihat dengan pengamatan di bawah mikroskop terhadap preparat usapan (smear) pada ikan yang diobati. Serangan penyakit sekunder seperti kebusukan sirip dapat dicegah dengan pengobatan menggunakan acriflavine atau pemandian mengunakan antibiotic.
- Trychodiniasis
Penyakit Trychodiniasis adalah penyakit yang disebabkan oleh Trichodina sp suatu protozoa bebenbentuk cakram dengan diameter sekitar 100 mikron dengan "gigi-gigi" yang terdapat di bagian tengah dan cilia pada bagian permukaan bawah. Pemberantasan/pencegahan penyakit ini dapat dilakukan seperti terhadap serangan "Cryptocaryoniasis" atau "Brooklynelliasis".
d. Jamur
Jamur merupakan tumbuhan sederhana yang tidak membutuhkan cahaya untuk tumbuh, tetapi memakan bahan organik untuk mendapatkan energinya.
Jamur dapat menyebabkan penyakit bila tumbuh pada organisme hidup termasuk ikan. Dewasa ini ada dua penyakit ikan yang berasal dari jamur, yaitu : Saprolegniasis dan Ichthyosporidosis.
- Saproleniasis
Penyakit ini disebabkan oleh jamur yang disebut Saprolegnia sp. Serangan jamur ini menyebabkan perubahan warna pada kulit dan tumbuh jamur putih keabu-abuan yang makin lama makin melebar, dan menyebabkan kerusakan pada otot. Ikan-ikan yang sakit tersebut sebaiknya diambil dari kurungan pemeliharaan. Penyakit ini jarang sekali ditemukan dan tidak mudah menyerang ikan yang dalam keadaan sehat. Penyakit ini terutama menyerang ikan kakap putih pada bagian sirip punggung dan melebar ke arah sirip ekor.
Pencegahan dan pengobatan
Pengobatan dapat dicoba dengan jalan diolesi :
• Larutan yodium Tincture 0,1%
• Larutan Potassium Dichromat 1%
Atau perendaman dengan menggunakan :
• Methylene blew 0,1 PPM, selama kira-kira 1 jam dan diulangi selama 3 hari.
• Ichthyosporidosis
Penyakit ini disebabkan oleh jamur Ichthyos poridium sp (Ichthyophonus sp). Jamur ini berkembang mengikis jaringan luar bagian kepala dan menyebabkan luka yan dalam yang berwarna kemerah-merahan dan dapat masuk ke dalam sampai ke bagian tengkorak kepala ikan. Kadang-kadang juga ditemukan di bawah kulit dan jaringan epitel kulit dari jaringan organ yang penting misalnya insang, usus, hati dan jantung dalam bentuk gumpalan granula.
Biasanya terdapat pada ikan kerapu dan berkembang lambat karena penyakit ini terutama teramati pada ikan-ikan atau ukuran pasar.Sampai saat ini belum ada pengobatan yang manjur terhadap penyakit ini. Beberapa jenis antibiotik yang biasa terdapat di pasaran kurang mempan menghadapi penyakit ini. Untuk itu dapat dihindari dengan jalan menjaga makanan dari ikan rucah yang diberikan agar bersih dan tidak ada gumpalan-gumpalan penyakit di bagian kulitnya atau di bagian lain.
e. Bakteri
Penyakit yang disebabkan oleh bakteri merupakan penyakit yang paling umum dijumpai pada usaha budidaya ikan laut.
Bakteri merupakan jasad renik yang kira-kira duapuluh kali lebih kecil dari sel-sel jamur, protozoa atau sel daging ikan. Biasa terdapat di udara, dalam tanah maupun dalam air dan benda padat lainnya. Sebagian besar bakteri sebenarnya tidak menyebabkan penyakit. Namun bakteri mempunyai kemampuan memperbanyak diri sangat cepat, sehingga apabila bakteri tersebut berada dalam bagian tubuh hewan. Bakteri ini bermacam-macam jenisnya. Yang menyerang manusia, berbeda dengan
jenis yang menyerang ikan dan tumbuh-tumbuhan. Tetapi ada pula jenis-jenis yang dapat menyerang manusia dan hewan sekaligus.
Ikan yang terserang oleh bakteri dapat memperlihatkan gejala yang berbeda-beda. Jika bakterinya menyerang kerusakan-kerusakan pada kulit yang terlihat seperti kena api (luka bakar), seperti kudis/borok yang membusuk.
Infeksi bakteri biasanya timbul apabila ikan menderita stres. Kematian banyak terjadi pada ikan yang menderita stres karena serangan bakteri yang menyebabkan infeksi. Penyakit bakteri merupakan jenis yang terbanyak didapati pada usaha budidaya ikan di laut. YC. Chong (1986) menyebutkan bahwa di perairan Siangapura terdapat 3 kelompok utama penyakit yang disebabkan oleh bakteri, yaitu : pembusukan sirip/ekor, Vibriosis dan Streptococcosis.
- Pembusukan sirip/ekor (Bakteri Fin Rot)
Bakteri ini biasanya menyerang sirip-sirip, terutama sirip ekor dan dapat mengakibatkan luka dan pengelupasan kulit. Ikan-ikan yang terserang penyakit ini akan menalami luka/kerusakan pada bagian tepi dan siripsiripnya, termasuk sirip ekor dan akan terkikis secara tidak teratur. Bahkan tidak jarang terjadi sirip yang terserang akan tinggal bagian pengkalnya saja.
Jika diamati pada bagian yang terkena penyakit atau bagian yang luka hanya sedikit terdapat protozoa, tetapi diketemukan
banyak sekali populasi bakteri yang terdiri dari bakteri Mycobacter sp. Vibrio sp, jenis-jenis Pseudomonas dan Cocci gram positif.
Diperkitakan bahwa kerusakan yang terjadi tersebut diakibatkan oleh serangan bakteri dengan populasi yang sangat padat. Bakteri ini mudah menular lewat luka-luka ikan yang lain akibat sentuhan ekor yang sakit. Bakteri yang paling dominan adalah Vibro sp karena mempunyai kemampuan yang baik untuk hidup di air laut dan pertumbuhannya untuk membentuk koloni lebih cepat dibandingkan dengan bakteri yang lain.
Pada dasarnya penyakit ini tidak begitu berbahaya, tetapi yang menjadikan bahaya justru infeksi sekunder jenis bakteri lain yang dapat memperparah penyakit tersebut dan menyebabkan kematian ikan.
Pencegahan dan pengobatan
Pencegahan dapat dilakukan dengan jalan perendaman ikan yang sakit ke dalam bak air dengan menggunakan :
• Nitrofurozone 15 ppm, selama 3 - 4 jam.
• Suplhonamide 50 ppm, selama 3 - 4 jam.
• Neomycin sulphate 50 ppm, selama 1 - 2 jam.
• Chloramphenicol 50 ppm, selama 1 - 2 jam.
• Acriflavine 100 ppm, selama 1 menit.
Sesudah pengobatan, tempatkan ikan ke dalam kurungan yang bersih dengan kepadatan yang rendah dan aliran air yang baik, atau pada bak dengan penambahan aerasi secukupnya.
- Vibriosis
Vibriosis merupakan penyakit yang disebabkan oleh bakteri Vibrio sp. Bakteri Vibrio sp termasuk kelompok bakteri yang heterogen dan gram negatif. Ada 2 bakteri penting yang diketahui menyerang ikan laut yaitu : V. alginolyticus dan V. parahaemollyticus. Vibriosisi merupakan penyakit sekunder, artinya penyakit ini muncul setelah adanya serangan penyakit yang lain misalnya protozoa atau penyakit lainnya.
Dari percobaan yang dilakukan terhadap bakteri yang diisolasikan dari ikan kerapu dan kakap putih yang sakit, ternyata bakteri ini tidak mampu membuat ikan menjadi sakit vibriosis setelah dilakukan penyuntikan dengan bakteri tersebut. Terkecuali apabila dosisnya tinggi.
Ikan kerapu yang terkena Vibriosisi akibat suntikan bakteri tersebut, akan mengalami perubahan warna kulit menjadi lebih gelap dan daerah bekas suntikan akan menjadi borok. Selanjutnya akan terjadi pendarahan pada bagian peritonial dan ginjalnya akan rusak. Pengamatan di alapangan juga menunjukkan gejala ikan kurang nafsu makan, busuk sirip dan akumulasi cairan di bagian abdomen.
Pencegahan dan pengobatan
Beberapa pengobatan dengan antibiotik dapat dilakukan antara lain :
• Menggunakan Oxytetracycline sebanyak 0,5 garam per kg makanan ikan selama 7 hari.
• Menggunakan Sulphonamides 0,5 gram per kg makanan ikan selama 7 hari.
• Chloromphenicol sebanyak 0,2 gram per kg berat makanan ikan selama 4 hari.
Apabila ikan tak mau makan, cobalah pengobatan dengan perendaman sbb :
• Nitrofurozon 15 ppm, selama lebih kurang 4 jam.
• Sulphonamides 50 ppm, selama lebih kurang 4 jam.
- Streptococcus
Bakteri dari genus Streptococcus ini kadang-kadang menyebabkan penyakit pada ikan laut yang dibudidayakan, seperti ikan kerapu merah dan ikan beronang. Tanda-tanda dari infeksi penyakit ini biasanya tidak jelas, namun ikan terkadang terlihat lesu, tidak sehat, berenang tidak teratur dan pendarahan pada cornea. Biasanya penyakit ini diamati lewat pemerikasaan laboratories.
Streptococcus sp termasuk bakteri yang resisten terhadap berbagai antibiotik yang secara terus menerus dipergunakan untuk mengobati infeksi bakteri yang lain.
Pencegahan dan pengobatan
Berikut adalah perlakuan pengobatan yang disarankan tes sensitivitas antibiotik.
• Amphicilin 0,5 gram per kg makanan ikan untuk 2 hari.
• Oxytetracycline 0,5 gram per kg makanan ikan untuk 7 hari.
• Erythromycin estolate 1,0 gram per kg makanan untuk 5 hari.
Dapat juga menggunakan penicilin 3.000 unit per kg berat ikan yang disuntik secara intramascullar.
f. Virus
Virus adalah patogen yang paling kecil. Ukurannya lebih kecil dari seperduapuluh kali besarnya bakteri. Virus menyerang mahluk hidup, berkembangbiak di dalam organisme inang dan pada saat itulah dia akan menyebabkan kerusakan ataupun penyakit pada organisme inang.
Virus sangat tahan terhadap segala jenis obat-obatan. Oleh karena itu, pemberantasan penyakit yang disebabkan oleh virus lebih ditekankan kepada upaya pencegahan dan membatasi penularannya. Salah satu virus yang telah diketahui menyerang ikan pada budidaya di laut adalah penyakit Symphocystis.
Penyakit Lymphocystis disebabkan oleh serangan virus yang termasuk famili Iridovirus. Virus Lymphocytis berbentuk partikel berbidang banyak dengan sekitar 0,13 - 0,26 mikron. Terdiri dari inti DNA yang dibungkus oleh lapisan protein.
Infeksi pada ikan yang terserang menyebabkan tumbuhnya sel jaringan. Sel yang dikenal menyebabkan tumbuhnya sel jaringan. Sel yang dikenal dengan nama Lymphocystis menyerupai butiran sagu. Kelompok dari sel tersebut membentuk tumor pada kulit dan sirip.
Ikan kakap putih merupakan ikan yang sangat rawan terhadap serangan virus ini. Virus ini juga terbukti sangat mudah menular dengan menggunakan air sebagai media penularannya. Oleh karena itu, ikan yang terserang harus segera dipindahkan dan dipisahkan dari ikan yang sehat.
Pada dasarnya, penyakit yang diakibatkan virus belum dapat ditanggulangi secara pasti. Namun demikian pencegahan dapat dilakukan dengan jalan vaksinasi dengan obat antibiotik. Masalahnya adalah hingga saat ini, obat/vaksinasi untuk penyakit ini belum tersedia atau sulit didapatkan di pasaran.

Sumber :
Ditjen Perikanan Budidaya