Fish Health

Anchor worm

An anchor worm attach to a fish’s body and when it is attached it a fish it will never move around on a fish’s once its attached. Anchor worm infests large variety of fished such as Goldfish. Treatment is by using DFD (difluorozrichlormethylmethane) in a bath at 0.1 millimeter of aquarium water for two to three minutes.

Bacterial Infections (Fin Rot, Tail Rot, Red Pest)

Bacterial infections often have internal effects as well as external ones. Treatment via tank water is liable to be less successful unless it is with a substance that will rapidly be absorbed by the tissues of the fish. Symptoms of some of the commoner bacterial infections of aquarium fish are clamping of the fins and tail with blood streaks or ragged areas visible. In extreme instances pieces of fin or tail drop off. This condition is also known as fin rot or tail rot.
Blood streaks or ulcerated patches on the surface of the body may be seen also; this is a condition frequently referred to as ‘red pest’. The scales may be raised with or without reddening of the skin beneath them. A very effective method of treatment is to mix antibiotics (0.1-1 per cent) with the food. Marine fish as with freshwater fish. bacterial infections in marine fish are frequent and of multitudinous origin. Antibiotic in the — aquarium appear to be the ideal treatment. Antibiotics, for reasons unknown. are less effective in salt water than in fresh water. The dose may be increased by five times.


Dropsy is a rather non-specific condition which has at in two different types. Symptoms of true dropsy are swelling of the body and abdomen without scale protrusion ex. in extreme cases. No external signs of the infection are usually The cause of true dropsy is usually a bacterial infection of the kidney causing upsets in fluid balance, and increased internal pressure. False dropsy, ‘red pest’, is accompanied by scale protrusion. are in fact this may be all that is occurring. The only worthwhile treatment appears to be application of mycetin, administered in the food.


The term ‘fluke’ is usually employed to describe the infestations of creatures smaller than fish lice or anchor worm- Fish infested with the flukes look pale and have dry fins. If the gills are infested there is rapid respiration and wasting. It mainly occurs in the cold water – Tropical fish are, however, infested from time to ti7- Look for greyish minute worms on the gills or skin. It 7. require careful observation to differentiate this infestation from white spot.
Treatment is best achieved with trichlorofon 0.25-0.4 7 7. of aquarium water. Alternatively formalin may be used as a treatment but not in the tank. A forty-five minute bath in 0.2 40 per cent formalin solution per liter of water is recommended.

Parasitic Infestations

Parasitic Infestations in marine fish occur similar to those observed freshwater fish. The treatment of choice is as described for freshwater flukes, but of course the – must be of seawater.

Fungal infections

Fungal infections are seen in freshwater fish, particular cold water fish. Usually only weakened or damaged fish susceptible, so the problem tends to be individual rather than a whole aquarium infestation. If only one or two are infected and it is possible to net them out without too much trouble, this is the best method of dealing with the condition. They should then be treated with a fungicidal bath.
The symptoms are a grey or whitish growth in the skin of the fish, often associated with visible damage from poor handling, wounds from other fish or severe attacks of white spot or other infestations. The growth may occur anywhere on the body or fins and will eventually assume cotton wool- like appearance protruding from the surface of the fish. The fish do not usually show great distress from the fungal infestation, but if left untreated they will eventually be killed by it. The fish therefore do not normally show the distress typical of velvet disease or white spot unless the fungus is subsequent to these particular diseases.
If fungal infections are not treated the fish will eventually die.
Treatment consists of zinc-free malachite green or brilliant green (dyes) in an isolated bath (a cup or jam jar or whatever is suitable according to the size of the fish) at a strength of 60 milligrams per liter. Immerse the fish in the solution for 30 seconds and return to the tank immediately after treatment. The cotton-wool-like tufts will eventually fall off in a few hours. Repeated treatments may be given but a single one is usually effective.
If a tankful of fish has the fungus, a different treatment is required. Phenoxethol at a strength of 1 per cent in distilled water is used here; 10 milliliters of this solution per litre of aquarium water is adequate. Repeat (once only) if absolutely necessary after two or three days.


This is a common fungal disease, characterized by the fish’s slow, sluggish movements with loss of equilibrium, possibly a hollow belly, and the appearance of yellow to black cysts or sores virtually anywhere on the surface of the fish. The fungal attack is essentially internal, and usually becomes apparent only when it is widespread and generally past curing. It is a disease of tropical rather than cold-water fish. Treatment of infected fish is frequently unsuccessful. It is best to destroy individual infected fish in the hope that the disease will not spread to the others. A big problem is that infected fish may live for months before showing signs of the disease. Two treatments are recommended, both given in the food: Chloromycetin at a dose rate of 1 per cent of the fish’s food mixed in with the food for three days, or 1 per cent phenoxethol solution at the rate of 10 milliliters per liter of tank water, once only.

Mouth fungus

The signs of mouth fungus are similar to the fungal infections mentioned above, but are usually confined to the mouth, starting with a white line around the lips and proceeding to the production of filaments of cotton-wool appearance. It is a highly contagious disease with tropical fish rather than cold water fish and is a rapid killer. Treatment must be given to the tank and its inhabitants or further infection will occur. The disease is so toxic and rapid spreading that an antibiotic should be used. The most effective treatment is Chloromycetin or Erythromycin at 20 milligrams per litre. This is administered to the tank water.

Marine fish

Fungal infections resembling ICHTHYOPHONUS cause similar conditions in marine fish to those already described. Feeding antibiotics offers the best chance of limiting the spread of the disease


Fish are prone to attack by a tremendous variety of so-called lice and flukes of various kinds, which are often quite difficult to eradicate. Removing the affected fish from the aquarium to treat it individually can be a nuisance because of the difficulty of trying to get it out of a large tank. Irritation is obvious, with the affected fish scratching itself against rocks or aquarium decorations. The parasite is often quite visible.
The fish louse may be introduced by live feeding, such as with Daphnia, or if fish have been taken from ponds. The louse is a flattened, rather spider-like animal, about 5 millimeters in diameter. which attaches itself by two large suckers to the exterior of its host and feeds on its blood. The lice may be physically removed using forceps. If there is a heavy infestation or if the fish are rather delicate and should not be disturbed by handling, it may be better to use Trichlorofon at 0.25-0.4 p.p.m. of aquarium water.
Poisoning by chlorinated water This can occur where city water supplies are chlorinated. Ridding the water of chlorine can be achieved by letting it stand for a couple of days—the chlorine passes into the air, and the water is safe to use. Alternatively, the addition of a few drops of sodium thiosulphate will instantly negate any chlorine present
Poisoning by Insecticides and Other Pesticides
This is common. Dichlorvos, a constituent of pest strips, is particularly toxic to fish and pest strips should not be placed in the same room as the aquarium. Avoid using aerosol insecticide sprays in the aquarium room. If it becomes necessary to do so, make sure the aquarium is well covered first

Popeye (Exophtnahnos, Gas Bobble Disease)

Popeye is a protrusion of one or both eyes, which may subside or may progress, leading to the loss of one or both eyes. It may occur in association with infectious disease, and treatment for the disease in question may cure the condition.
The eye or eyes affected should be carefully inspected to make sure that the cause is not so-called gas bubble disease. If the condition is not caused by an existing infection, true gas bubble disease due to the deposition of gas, usually nitrogen, in the tissues in the eye should be suspected. In this case, popeye resembles ‘the bends’ and if the eyes are showing these symptoms then it must be realized that similar bubbles may be forming elsewhere in the body and be the cause of severe trouble.
When gas bubbles are seen in the eyes, the water temperature in the aquarium should be lowered as far as is tolerable to the fish species concerned to increase the solubility of the gas. Any brisk aeration should be cut down as far as feasible. It is possible if small bubbles in the eye coalesce to form a visible large bubble, to extract this with a fine hypodermic needle. This is a job for a veterinarian.


It is not only diseases that may cause symptoms of illness in fish. Sometimes chilling, over-heating or poisoning may be the cause. Either a sudden fall in temperature or continued exposure to a temperature lower than that to which the fish are accustomed will result in a condition called `Shimmies’. In this condition the fish adopt a slow swimming movement which is non-progressive. The temperature of the aquarium should be raised to 27-30°C and kept high for a few days.
Care should be taken to avoid a sudden rise in temperature or chronic high temperatures as this can cause trouble. The usual signs are gasping at the water surface or darting around the aquarium. However, this usually occurs at 30-33°C. While it is feasible to raise the temperature to 30°C reasonably quickly, it is dangerous to lower the temperature quickly. Overheated fish should have maximum aeration instead. ‘Shimmies’ may also be a sign of velvet disease in marine fish.

Tuberculosis Patchy

Discoloration of the skin accompanied by emaciation is usually termed tuberculosis.

Velvet disease

Velvet disease is caused by a flagellated parasitic organism called Oodinium. Irritation, rapid respiration (gill movement) and clamping of the fins are symptoms common to a number of diseases and any fish showing them should be examined carefully. In velvet disease a very fine golden or brownish dust covers the surface of part or all of the body and fins. If looked at very closely it can be seen to move rather like corn in a breeze.
Velvet disease is highly infectious and kills most of the specimens it attacks, particularly fry (the young, recently spawned fish). Immediate steps should be taken to eradicate the condition. The preferred treatment is a solution of blue crystalline copper sulphate in distilled water at the concentration of 1 per cent. This solution should be used at 1 milliliter per 10 liters of aquarium water. The alternative treatment is with 0.2 per cent stock solutions of monacrin or acriflavin, adding 1 milliliter per liter of aquarium water.
The addition of a teaspoonful of common salt (approximately 5 grams) per 5 liters of aquarium water helps the action of the drug. Monacrin is the preferred treatment as it forms a weak blueish solution in the aquarium and looks attractive rather than otherwise—acriflavin gives a darker, yellowish appearance. It is not necessary to change the aquarium water to a greater extent than normal after the use of these preparations, although acriflavin has been said to sterilize fish. If the fish are intended for breeding, all the water should be changed gradually after the cure has been effected.
Velvet disease in marine fish is related to the well-known freshwater pest, the usual active agent in the marine tank being a close relative. It also infests the gills and outer surface of the fish but usually is white in color and often quite difficult to see unless carefully sought out under a stronger light. It is easiest to detect on the dark surfaces of the fish. It is more predominantly a gill disease in the marine fish.
The usual signs are increased respiration, scratching against rocks and coral, and quite often ‘shimmies’. The copper sulphate treatment of velvet disease for freshwater fish can be used successfully in the marine tank. Marine fish can take a higher dosage than recommended for freshwater treatment, and can stand up to about 0.4 parts per million of metallic copper. Biological filters and other types of filter that may extract copper should be turned down or off during copper treatment and brisk aeration supplied by other means.
White spot, or ich (pronounced Ick) White spot used to be the most common disease in freshwater tanks, but has been displaced by velvet disease. The symptoms of infestation by the parasite are irritation and glancing (bumping against) rocks and plants, usually with severe gill irritation since the parasites are filtered off by the gills (as with velvet disease). This causes the fish to rub the nose and head region against the plants or rocks. White spots up to I millimeter across appear. The gills are often severely infected and respiration impeded before many spots are visible on any other parts of the fish. Eventually body, fins and tail may be covered by the spots in untreated fish.
The drug of choice is quinine hydrochloride at 30 milligrams per liter of aquarium water, or quinine sulphate which is less soluble but may be used. Quinine is not effective against velvet disease, just as copper, monacrin and acrifiavin are not effective against white spot. The best method of treatment is to dissolve the total dose required in about 1 liter of water and add it to the tank a third at a time at twelve-hourly intervals. Aeration should be as brisk as possible, and the water may cloud. It is not necessary to change the water afterwards. As with velvet disease the cure is not sudden. The higher the water temperature, the quicker the result. The treatment should not need repeating because the drug acts on the free swimming larval stage of the parasite. If there is a renewed outbreak, it should be treated with quinine again. More than one additional dose of quinine is not advisable as quinine starts to become toxic if administered for too long.

White Spot Disease

White spot disease in marine fish is similar to the white spot found in freshwater fish. The best treatment is with copper sulphate exactly as described for marine fish for velvet disease. Copper treatment is effective in the marine tank—not in the freshwater tank.