RE: NANFA-L-- Mystery tentatively solved

Bruce Stallsmith (
Wed, 28 Jun 2006 10:04:37 -0400

I've had a similar affliction killing striped shiners in my tanks.
Ironically, one of my students is studying gill parasite infestations in
local scarlet and striped shiners. We go out every so often to collect live
shiners, and keep them in tanks until we need to sacrifice them. The last
two batches of striped shiners have gone down hard with an aggressive tail
rot, which I've suspected was protozoan in nature but haven't had a chance
to prove. Interestingly, the scarlet shiners don't seem to have been
affected-in-all, and some incidental catch such as blackspotted topminnows
and telescope shiners are also fine. Many parasites are very host-specific
and this seems to be the case here.

I think the name Cyclochaeta is out of use, and looking through Glenn
Hoffman's "Parasites of North American Freshwater Fishes" I find no
reference to it. But I'd hazard a guess that these protozoa are genus
Trichodina, usually gill parasites but capable of whole body infestations. I
hope to look and see; we might be going out today for more shiners, and I'll
keep a close eye on the stripeds.

--Bruce Stallsmith
the balmy, dry Tennessee Valley
Huntsville, AL, US of A

>From: "Mysteryman" <>
>To: <>
>Subject: NANFA-L-- Mystery tentatively solved
>Date: Wed, 28 Jun 2006 08:00:20 -0500
>That weird mystery malady that was wiping out my Rainbow Shiners has been
>narrowed down to a ciliated protozoan. These little beasties are in the
>of attaching to the caudal fin, tearing it to shreds, and feasting on the
>blood. Loss of blood is apparently the cause of death for the affected
>although no bleeding is visible unless the crust of parasites is removed.
>gills are strangely left alone; the parasite has a strong affinity for the
>caudal fin. The other fins are also largely ignored. The white crusty
>appearance is due to a congregation of thousands of the creatures piled up
>the fins & each other. Just how they swarm so suddenly in such great number
>and attach to fish in such a very short time is something I haven't figured
>out, but it does-in-least explain the way the fish are fine all night and
>attacked in the morning. I guess the parasites wake up-in-dawn and begin
>Antifungal & antibiotic meds seem to retard their growth & spread for a
>while, and antiparasite meds knock them down for a lot longer. I gave the
>a massive dose ( 3X normal ) of Coppersafe, and after about 10 days with no
>further outbreaks the problem seems to be solved, although the fish are
>obviously unhappy about the copper. A few massive water changes might help
>them through it.
>Normal copper doses weren't having any useful effect. I would guess that a
>strong dose of Clout or similar might also work.
>I never did get around to sending any specimens to a lab, but I will. I
>used my own microscope and pored through a whole bunch of books on the
>subject, finally finding one obscure reference in a very old book printed
>when people still commonly kept natives. No physical description of the
>parasite in that example is given, so I don't know if that's the culprit.
>Cyclochaeta is the name of it, or-in-least it was way back then, and the
>symptoms described are a good match for what my poor little rainbows
>I've never before heard of this Cyclochaeta, and that's odd in itself,
>since I
>have a LOT of books on the subject of fish diseases. Oh, well; the newer
>have long had the irksome habit of leaving out good stuff from times past,
>Anyway, I figured you guys would like to know about this irritating little
>beastie in case you have the same symptoms in your fish someday. This
>knowledge came too late to save my Rainbows, but my Flagfins are okay.
>my Bluenoses were never exposed; I'm sure they wouldn't have had a chance.
>By the way, the Warmouth milt has had zero effect on the bluenoses in
>to making them spawn, although they are in full spawning condition and
>courting constantly. ( Quite a sight! Who needs Bettas with this action
>on? ) I guess I'm gonna have to find a Longear.
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