Does anybody know anything or have any experience with this disease? I'm still trying to figure out why my fish are all doing so poorly, so I'm grasping at straws a little. I found it listed under internal parasites in a book on fish health I picked up a while ago, and this is what I found online:

"Digenetic Flukes (Metacercaria)
Typically seen in newly imported fish and in two forms. Black spot is caught from snails that release the Cercaria. Larval forms penetrate the skin and encyst in the tissue and may be seen as red or black nodules. If eaten by a Bird for instance they then develop into adults. Sanguinicola disease passes from fish to snail and then back as minute worms that live in the fishes bloodstream. There they lay eggs that block up the blood vessels which in turn causes Necrosis. As far as I know there is still no cure for this problem."