External parasites killing dwarf puffer
Yesterday my dwarf puffer became very ill out of nowhere...he was fine at about noon and by 6 he was "breathing" heavily in the corner of the tank. I tried to get him moving around and he just cruised around aimlessly for a few minutes, didn't really notice me at all, and then went back to the same spot. This morning I noticed that some of the little planaria-like creatures that lived on an algae-covered rock in the tank had taken up residence on his skin, and there has been an overall population boom in the tank; they're all over the glass near the substrate. He's really lethargic and moves around every once in a while but his little fins are going slower than I've ever seen them move. I'm going to try to feed him in a few minutes once the bloodworms thaw.
What medications can I try to get rid of external parasites? Is there anything else that could be making him sick and the planaria are just taking advantage and not actually causing the problem?