Peninsula Cooter

Question
I have a small hatchling about an inch big, who I believe is a peninsula cooter, although I am not 100% sure. He is in a 10 gallon tank that I can't fill all the way up, so I am going to be putting him in a big 55 gallon tank. My questions are: Would that be to much for him? Is there any other animal(fish, turtle, etc.) that I can put in the tank with him? I was thinking about adding a sucker fish or something but I was told that the turtle will eventually eat it. Also, I recently noticed that on the bottom of his shell, (has always been yellow with no marks), some of edges are turning brownish, but they look like they are scrapes or rough. Also at both sides of the bottom, he now has what appears to be tiny cracks. Are these things normal? He doesn't appear to be hurt and he is acting the same as he always has. Thank you for your help, and please let me know if you need any further information.

Answer
You can try to ID the turtle at http://www.ausinsturtlepage.com and their 'World of Turtles' Photo Gallery. They also have excellent care sheets and articles there.

Other tank mates can be tricky. Fish should be big, fast, and/or armored. Armored cats usually do OK but turtles often nibble at or harrass other animals in smaller tanks (and yes, a 55 will still be a pretty small tank in a very short time!)

Belly shell, called the Plastron, often changes color as the turtle ages, and there might be some rough spots on the basking material. For example, rock basking sites commonly scratch the shell pretty bad.

Tiny cracks in an otherwise healthy shell are not a big deal. At about 1", the shell should still be a little 'springy', especially on the pastron. Make sure it is getting a good diet and cares (see the above site) and things should be fine for it!

Good luck!