Re: NANFA-- parasite removal

unclescott (
Sat, 31 Jan 2004 12:00:31 -0600

Your advice about quarantine and faithful maintenance is so true Stan.

However sometimes there is a malady which is not effectively dealt with by
quarantine. For instance there are a number of Camallanus species, according
to geography and climate. Other hosts in their cycle can include species
specific Cyclops, birds or even people who eat under cooked or raw fish.

Camallanus may also be ingested by the fish without an intermediate host.
When the live bearing adult worms can be seen extending from the fish's anus
is when they are releasing larvae. The stage one or L1 larvae only have a
rudimentary intestinal system, but a tail which waves invitingly in the
water. Fry will suck them up. The larvae set up shop in the intestinal
tract, develop an effective digestive system, go through other larval stages
and reproduce all while drawing nourishment through the intestinal walls.

Here's the kicker. We, even if very observant, will not see them for months.
The tropical C. cotti takes 3-4 months to complete their life cycle. Maybe
cold water species take longer. They will usually outlast quarantines.

I'm still mulling over Bruce's suggestion that medication may not be
effective with cysts or some egg cases and that further medication may be
necessary. Immediately a lot of wee beasties came to mind and my complacency
gurgled down the ceramic file.

The good new: the various anthelmintics, added to the water and absorbed by
the fish (through the gills?) will kill both the internal worms and swimming

Elsewhere the question was raised as to whether aquarium snails could also
be hosts to them. I don't know. But the anthelmintics will begin killing off
snails if left in the water for an extended period of time, so the stuff
must be absorbed by them.

Water changes and a healthy environment obviously will help the fish
maintain themselves, but one wonders if problems with Camallanus and other
worm or helminth infections wouldn't inevitably become a problem.

This might be a case where preventative applications of anthelmintics in
quarantine would be the most beneficial. Worm damage will only be more
extensive as time goes on.

All the best!

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