> Peter Unmack has raised the emphasis on another disease mentioned by
Adrian Tappin - Velvet. This is another of those that generally starts
>Some form of copper seems to be the best, but
that is a rather toxic compound and the doses have to be carefully
I never worried about the light. The only thing that I used with success
was copper sulphate and unfortunately I forget the dosage. I think I
just made up a solution and added drops until the fish looked unhappy and
dropped it back. It was kinda nasty as usually the only way to tell was
by trial and death! Of the 15 or so species I treated only sexlineata
had a really low tolerance to copper. I treated every single rainbow,
once I got the dosage right on the tank I would just move the fish into
the copper and steralise their tank. I treated every tank in strict
isolation to avoid cross infection. I have a vetinarian helping me. I
would treat a tank with clout and all would appear well. The vet would
do a slime scrapping and sure enough velvet would still be there but not
visible to the naked eye. Sometimes the velvet infection would look
a litttle different too, perhaps smaller lesions/spots on the fish in
some outbreaks. I suspect that most treatments nearly kill all the
parasites, but a few remain which don't neccessarily bounce back and
cause a problem. These few can either reinfect again or get transferred
to a new tank via syphon hoses etc. The one nice thing about copper, no
more gill flukes (which can be brought in from wild bows) and damn
snails! I learnt two lessons from this, 1/ I couldn't have solved this
problem with out the help of a vet (or at least with a microscope), and
2/ don't unneccessarily risk cross contaminating your tanks in a fish
room because by the time you recognise the problem you may have already
spread the infection further.
Velvet also seems kinda specific to certain fish. I had a number of
other natives that never had velvet even though I am sure they were
exposed to it. White spot can sometimes be the same, I had southern
pygmy perch and Yarra pygmy perch together, the southern got white spot
and the Yarras didn't. Same too with the susceptability of some of the
galaxiids, truttaceus are far more susceptible than maculatus. I had a
galaxiid tank with ~4 or 5 species which had white spot for about a month
or two. It never became very common and only a few of the fish were
effected. I would treat it but it would come back as the galaxiids were
slightly stressed due to heat. Ended up beating by maintaining salt at
(10 g/litre).
Tootles
Peter Unmack