| Two fish parasites are commonplace in the marine aquarium. These are Cryptocaryon
(white spot) and Amlyoodinium (oodinium,, marine velvet, coral fish disease). The
key to avoiding an infestation is to provide conditions that promote good health in the
fish population. In the ocean, the fish's immune system largely protects it from
infestations. In the aquarium, maintaining good health in the fishes involves, first and
foremost, practicing good aquarium management. When you bring a new specimen home, place
it in a separate tank for a couple of weeks to observe its behavior. This will prevent any
problem that may develop in the new fish from spreading to other, established specimens.
In addition, isolating new specimens in a separate tank makes the job of treating them
much easier, if a need for treatment does develop. Symptoms of Infestation
Symptoms of Cryptocaryon and Amyloodinium include rapid shallow breathing,
scratching, hiding, poor appetite, loss of color, and the appearance of small white dots
on the fish's body and fins. These parasite problems commonly appear in fishes that have
recently been subjected to some form of stress. When a fish is under stress, it is more
likely to succumb to a parasite infestation. In our experience, more aquarium fishes are
killed by Amyloodinium than by Cryptocaryon. In fact, we think deaths attributed to
Cryptocaryon have actually been the result of Amyloodinium, with the other
parasite a secondary invader. We have seen fishes recover from Cryptocaryon without
treatment. This has not been the case with Amyloodinium. Further, it is known that
the latter parasite produces a substance, apparently not unlike that involved in "red
tides," that is toxic to fishes. This is in addition to the Amyloodinium
organism's penchant for feeding upon and destroying the fish's gills, causing death by
oxygen starvation if left untreated.
Diagnosis
Beginners may not be able to diagnose Amyloodinium until it is too late to save the
fish. By the time external symptoms appear, the damage has already been done. Our advice
to beginners is simple: if any fish in the tank appears to be breathing at a more rapid
rate than the others, or more rapidly than you are accustomed to seeing as a
"normal" breathing rate, treat the entire fish population promptly with copper.
The breathing rate in fishes is somewhat influenced by temperature, so all the fishes in
the same tank should be breathing at the same rate, under normal circumstances. Chasing a
fish with a net, for example, will increase its breathing rate, but the rate soon returns
to normal. This is analogous to what happens to you if you are walking down the
street and have to break into a run suddenly to catch the bus.Your breathing rate will be
rapid, but will return to normal as your body adjusts itself. When a fish's gills are
damaged by a parasite infestation, the fish breathes more rapidly to compensate, and
normal breathing does not resume until the infestation is alleviated.
Treatment Procedure
Should treatment for white spot or coral fish disease become necessary, the only truly
effective medication is copper. Use an ionic copper medication, and use a copper test kit
to determine when the correct dosage has been added to the treatment tank. A copper
concentration of 0.15 - 0.20 ppm is most effective. Below 0.15 ppm, the treatment will not
be effective; above 0.20 ppm, the copper is stressful to the fishes. Copper medications
should never be used in a tank containing invertebrates, as most invertebrates are rapidly
killed by therapeutic levels of copper. This is another good reason to have a separate
treatment tank.
Angelfishes are somewhat more sensitive to copper
treatment. Before exposing an infected angelfish to copper, attempt to cure the problem
with a medication containing formaldehyde and malachite green, applied according to the
manufacturer's directions. If the infestation is severe, however, copper treatment should
be started immediately.
Signs of Cure
Fishes usually resume normal breathing within a day or two of beginning copper treatment.
Spots may disappear overnight, as if "by magic," but this is a normal part of
the parasite's life cycle. Do not assume all is well if this happens. Continue treatment
for two weeks, no matter what. Meanwhile, try to determine what may have been the source
of stress, and eliminate it if possible. If the specimen is new, chances are the stress of
capture and movement were the only problem.
Properly administered copper treatment is rapidly and
universally effective in dealing with Cryptocaryon and Amyloodinium. If
results are not achieved within 48 hours, it is likely that the problem has been
mis-diagnosed. Seek advice immediately regarding alternative action that should be taken.
The chances of curing any disease problem in marine fish are best when water conditions
and nutrition are correct, and the problem is treated promptly. |
