Page 229 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

HEALTH CONCERNS 227

PARASITES

CONDITION AT RISK SYMPTOMS TREATMENT
① Marine velvet All fish Rapid gill motion in early stages, because the gills are Isolate and treat rapidly with commercial remedy,
disease typically the first site of infestation. About four days usually one containing copper sulfate. The free-
later, velvety patches become apparent on the body, and swimming parasites can be destroyed by using
the eyes may become cloudy. The velvety look will spread an ultraviolet sterilizer; dropping specific gravity down
over the entire body. Advanced cases display small, white to around 1.010 will also kill parasites in the water.
spots, as if the fish has been rolled in powdered sugar.
Fish may die within two days of initial exposure.
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② Marine white spot All fish White spots, around ⁄32 in (1 mm) across, spread over the Isolate and treat with a commercial remedy. Continue
fish’s body and fins. Infected fish typically try to relieve treatment for at least a week after the fish appears
irritation by rubbing themselves on the tank decor. Other to have recovered to reduce the likelihood of return
symptoms can include clamping of the fins, cloudy eyes, outbreaks. Ultraviolet sterilization can help to curb
and even hemorrhaging. Caused by the protozoan spread of the parasite. Watch out for secondary fungal
Cryptocaryon irritans. and bacterial infections.
③ Brooklynellosis Anemonefish Typically excessive mucus production, resulting from the Use a commercial remedy. The condition responds
protozoan’s irritating effect. The excess mucus may make well to treatments based on formalin or malachite
the fish appear duller in color. Other signs often include green. Freshwater bath often beneficial. Maintain
labored breathing as the gills become damaged and good water quality and low stress levels to prevent
increased loss of color. The gills may hemorrhage and brooklynellosis in aquariums.
small red spots may be observed. Heavy infections will
usually cause the death of the fish.
④ Black spot (tang All fish, including tangs Affected fish develop a series of blackish cysts no more A freshwater bath combined with a commercial
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turbellarian disease) than ⁄16 in (2 mm) in diameter on the body and fins. remedy (usually based on formalin) will destroy these
The spots are clearly visible on light-colored fish but parasites, which are the larval stages of flatworms.
inconspicuous on darker species. The spots cause Watch for signs of secondary infection.
irritation, and the fish may rub repeatedly against the
tank decor. Other symptoms include reddened skin and
listlessness. The cause of this is a flatworm, which remains
on the host for about six days and then drops off on to
the substrate. Five days later the body wall of the adult
worm ruptures, releasing hundreds of young.
⑤ Head and lateral line All fish, with tangs Obvious pitted appearance on the head of affected Causes of the condition are unclear. Possible factors
erosion disease most vulnerable fish, with erosion of the area over the lateral line. include poor water quality, high nitrate levels, poor
Fish become lethargic, and open wounds provide nutrition, or infestation by the protozoan parasite
access for other bacterial and fungal pathogens, Octomita necatrix. If affected, treat rapidly with
which may eventually kill the fish. Also known as medicated food. Addition of vitamin C to the diet
hole-in-the-head disease. may help in long-term prevention.
⑥ Flukes All fish Symptoms include rapid breathing, in the case of gill Use a commercial formalin-based treatment.
flukes, and irritation. Fish suffering from skin flukes will A freshwater bath can help to overcome these
often rub themselves on tank decor. Cloudy eyes and parasites rapidly.
color changes may also indicate infestation. There are
many species of flukes, and these parasites are common on
imported fish. Microscopic examinations of skin scrapings
and gill clippings are required for positive identification
of parasite species.
⑦ Intestinal worms All fish Not easy to identify with certainty, but worm infestation Specially medicated foodstuffs containing an
is possible if a recently acquired fish starts to lose weight anthelminthic will overcome these parasites, which
rapidly or develops a swollen abdomen. The internal are then voided from the fish’s body.
gut parasites deprive the fish of nutrition, so affected
individuals appear quite lively but tend to display a
ravenous appetite.
⑧ Uronemosis All fish Early sign of infection is skin discoloration, leading to Rapidly fatal if internal organs, such as the kidneys,
ulceration; may be confused with bacterial disease at are affected. Treat the fish in a freshwater bath, or in
this stage. Skin sloughs and may also become pitted, a medicated bath containing a combination of formalin
distinguishing this from brooklynellosis. Some fish, such and malachite green treatments.
as seahorses, may, however, show no external signs, simply
developing respiratory complications.

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