Ergasilus Or Other Parasite, How To Determine And Treat?

[MattyD]

I need help identifying and treating what I think may be Ergasilus (or some variation thereof). I have a 46 gallon community tank which includes tetras, corydoras, and dwarf cichlids (blue rams and Apistogramma Borelli). Prior to the dwarfs I had angelfish. I have kept fish, including cichlids for many years but for the past two years I cannot seem to keep cichlids alive for very long. I have noticed a tiny white organism swimming through the gravel at the bottom (about the size of a grain of salt but it is NOT ich). I have tried several treatments based of the advice of the local fish shop to no avail (I am certain one of the treatments killed my Borelli, not the organism). While some of the treatments have reduced the total number of these creatures they always come back. There is no visible evidence of them on the fish and everything I read about Ergasilus seems to indicate that what I have is not exactly the same as their size is so small. I thought I had recently beat this blight but after sustaining 6 new rams for two weeks I woke up this morning to find one of the females on the bottom of the tank, breathing rapidly. And there, in the gravel, the tiny, white, swimming organisms. The symptoms are always the same, fish eat and seem healthy at first but suddenly begin breathing rapidly and then either sink to the bottom or hang out at the top of the tank in a corner. Once this behavior is noticed the fish usually dies within a day. As I mentioned, the tetras and other fish seem to be immune. Also, I change my water every other week, approximately 1/3 total volume, with a gravel vac. Regular water testing at the local fish shop indicates that my water quality is very good.

Please help! I don't want to kill any more fish!

-MattyD

 

[Colin_T]

ergasilus are male copepods. You can usually see the females moving around on the glass. They are small and have a V sticking out of their back. The V is a pr of egg sacs. The male copepods get into the gills and do the damage, whereas the females just move around the tank. They normally hang out on the glass but might swim around the bottom.
Copper sulphate should kill them. Careful when using copper as scaleless fishes like corydoras don’t like a full dose. Check the instructions on the packaging of any medication you use.

If the cichlids suddenly start floating or sinking then it is probably a swim bladder issue. This can be caused by an internal bacterial infection damaging an internal organ. Once this happens the fish die. Tuberculosis causes these type of symptoms. The bacterium destroy an organ and the fish 's body cavity fills with fluid. The fish breathe heavily before dieing shortly after. TB usually causes some bloating of the fish and a stringy white poo is sometimes seen.

If the problem was gill flukes I would think the other fishes would also be affected.