I have 3 small green spotted puffers in a 30 gal brackish tank. <adorable fish... you are keeping them brackish, right? what's your salinity?> They are all eating well and are very lively. I have had them about two weeks and two of them have developed small bumps (no discoloration-just raised areas) under their skin. The bumps were first noticed on their bellies and now one fish has a couple on his side. I need help in determining what these bumps are and if I need to treat them. Please reply-Thanks for the advice. <tough to diagnose from a general description of the symptom, but here goes: if the bumps/dots are symmetrical and identical in size... and not larger than a common grain of salt (as opposed to an uncommon 5lb grain...in which case you can forget the quarantine tank and just find a small deer to lick it off, hehehe) you may very well be dealing with an external parasite. Not at all uncommon with this species and not as obvious to you compared to pictures of large-scaled fishes in books. You must be very careful using medication with these fish and follow manufacturer's recommendations for scaleless fishes (or halve the dose for twice the time). Otherwise, large or asymmetrical bumps will rule out most if not all common parasites and you'll look for other pathogenic symptoms. I would highly recommend Dieter Untergasser's Handbook of Fish Diseases. A great and easy to understand book with pictures and fool-proof flow charts. We need to narrow the puffers condition down before we medicate. In the meantime... look for medicated fish food at the LFS and maintain consistent water quality. I'm (educated) guessing that your fish have common white spot and will need a parasite medication. Keep us posted, Anthony>