Possible intestinal worm in gobie

[whiteshark]

I posted a question in another forum about my six spot gobie. Long story short, he eats what I feed him (Mysis, brine, prime reef) but never fills out. He gets a bulge in his belly and by morning he is skinny again. Someone said there was a possiblity it had a worm, others said they just don't get real fat (quick metabolisim maybe?). He acts fine, and doesn't seem sickly. Do you think it could be a worm and how do you treat it?

 

[SAT]

Internal parasites are plausible. I suggest moving him into a treatment tank and using a medication containing praziquantel. I haven't used it, but "Ultra Cure PX" looks like a good choice (Drs. Foster & Smith sell it).