Tiny Turtle - what is it? How do I care for it?

the turtle requires water deep enough to swim but must have a basking rock so he can crawl out of the water occasionally to dry his shell; the water should be lukewarm to cool; never hot; the feed I give is: I buy cans of "tuna; shrimp and or canned clams; this is a high protein diet; then add little bits of lettuce for fiber; feed him clams one bit at a time...a.