Help!

Hi,
I've had my axolotls for about 5 months now.He makes little attempts at eating his frozen beef heart, but doesn't really eat. I tried worms, he got it in his mouth then gave up. He floats, a lot! He peels, but not that badly. He is extremely thin, we think his tank mate attacks him because he has little scabs on his tail. Today he had food coming out of his gills. Once I got the food out, the 2 gills had lost their feathery texture, and they are now curled forward. The other axolotl is fine. Please help!

It is quite possible there is an underlining problem such as illness but I think the main cause of him not eating is probably stress. If you suspect his tank mate is attacking him move him to a different tank or seperate them with a tank divider. My axies always love worms, and if he got the worms in his mouth to begin with, try cutting them up into really quite small pieces that are easier to tackle. You could also try bloodworms, as these are typically smaller. Can I just ask if you know your water parameters? I've heard of people having axies that cope differently to poor water quality. Some just seem more susceptible.
You say you've had him 5 months, has he never eaten? How long has he been like this?
And just to get a better idea, what temperature are they, what substrate are they on etc. Any bright lighting?

I'd like to add a couple more questions to iheataxie's excellent list:

What do you mean by, "he had food coming out of his gills"? Do you mean that there was eaten food actually emerging from the gill slits behind the feathery gill stalks? Also, how did you remove it?