I have a 60 gallon fresh water tank. To the best of my knowledge my water quality is good. ( I took it to a local shop and had it tested...everything came out normal). I purchased a green spotted puffer at Petsmart (risky..i know) two days ago. It was acting fine at the store, swimming around, came to the glass etc. though its fins were a little ragged due to the numerous other GSP puffers in the same tank. When i got it home, it nibbled at some shrimp but since then it has refused to eat and is uninterested in any sort of food. ( I have tried really small snails, ghost shrimp, frozen shrimp, plankton and blood worms). I tried garlic with no success. I even put the puff in a small breeding net with food thinking it was intimidated by the other fish in my tank (one bala, two rainbow fish, one rainbow shark, three barbs, one catfish, an algae eater and two rope fish). After reading numerous entries on this site and figuring out what to look for, I noticed it had stringy poop hanging off of it. He also is very lethargic and seems to be "sleeping" almost all the time with a darker coloration. The rare few minutes he is not "sleeping" he seems to almost regain full color, but still appears fairly dark.
I read that he should be fine in freshwater until he is a little bit older, (He is about half an inch, maybe smaller) and then added to Brackish water. I am worried the poor guy is starving himself to death, before I run out and spend money on medication I wanted to hear what you guys thought....is this a parasite or something else? If you think it is a parasite what is the best brand/type of medication to get to treat it? ( I read on this site that you should soak the food in the medication for internal parasites...but this guy will not take a bite of any food) Any advice is great....I just want to save my poor puffer...THANKS!

