Features of a Diamondback Terrapin

The Defenders of Wildlife website reports that the diamondback terrapin ranks as the only turtle in the world to live exclusively in brackish water, which is lower in salt concentration than seawater. Terrapin habitats range from tidal marshes and creeks to lagoons, but the turtles are commonly found in tidal estuaries west of the Connecticut River. Terrapins, like all turtles, are cold blooded, lay eggs and have hard shells, webbed feet and scales.

  1. Description

    • The Diamondback terrapin has a gray, black or light brown top shell -- or carapace -- with concentric folds or rings. The carapace is broad but leaf-shaped, and widest towards the animal's rear. The plastron, or bottom shell, of diamondback terrapins ranges from a yellowish to greenish olive color, and sometimes exhibits a pattern of symmetrical dark splotches. The heads and extremities of terrapins may also have spots.

    Gender Differences

    • Female diamondback terrapins are significantly larger in size than males. Females can grow to 6 to 9 inches long and reach a weight of 1.5 pounds while males can weigh up to a half-pound with a length of 4 to 5.5 inches at most, according to the Connecticut Department of Energy and Environmental Protection. Interestingly, what determines the gender of diamondback terrapin progeny is nest temperature, with higher temperatures resulting in female offspring and lower temperatures leading to male offspring, explain the Defenders of Wildlife.

    Life Cycle

    • Terrapins nest on sandy beaches from June to July. Females dig holes up to 8 inches deep and deposit an average of nine leathery, thin-shelled eggs that hatch within 15 weeks. Young terrapins sometime spend the first winter in the nest, emerging the following spring. Adult terrapins normally hibernate during the winter by nestling into the mud of swamps and estuaries.

    Diet and Status

    • Diamondback terrapins feed on snails, worms, clams, crabs, marsh plants and fish. In the beginning of the 20th century, diamondbacks were considered a gourmet food, according to the Connecticut DEP website. While terrapins are no longer hunted for food, ongoing threats to the population include habitat destruction, road construction and climate change. Ranking as a species of concern under the Endangered Species Act, terrapins qualify for legal protection in a number of states.