I came home from work today to my new baby RES floating in the water. His tail was beneath the dock but the rest of him was not. The way that he was floating scared me so I picked him up and put him on top of the dock.
He has been sitting there for an hour now; no movement, no signs of life. The only thing that I have noticed is that his right eye seems to have closed more than it was before and his head has gone further into his shell.
When I found him, both of his eyes were only half open and his head was half in his shell. Now, one eye is half open and the other one is mostly shut. His eyes are not swollen or puffy. He is not reacting to being picked up, being splashed or being approached by his brother/tank mate.
I just don't know what to do.

