Sorry, came back on line. That is the diamond back terrapin (Malaclemys terrapin terrapin) state reptile of Maryland. It is protected in a couple states and regulated by season and catch limits in some others due to it being a delicacy. They are found along the coast from Massachusetts to the eastern Gulf of Mexico and are unusual in that they are mainly brackish water though often found in fresh. That one is out early but they are pretty tolerant of low temps. they do need a basking area. They sometimes eat plant shoots and tubers but their main diet is clams, snails, shrimp, crabs, worms, and small fish. the males get a carapace length of 5 1/2" and the females up to 9". They breed in june or july and are pretty common in Chesapeake bay salt marshes. They have lived in captivity at least 40 years. Very cool find. Room temperature is a good temp. for them.