Its probably a Pleco, which grow to be really big... Def. needs more than a 55gallon. You can't leave it in a pool because it needs temps of around 80F. They arent very aggressive, but easier to handle if only one of them are around. I had one but it just got too big and gave it away. You would have to ship this one or maybe even 2 day shipping max, post this in your local craigslist for $15-20 and Im sure people will want it. I posted some random fish for 5$ since I was moving and got at least 20 emails