Size: The shell size of the male averages 5 inches. The female is larger than the male, with shell size averaging 7.5 inches.
Range: Cape Cod to Texas along Atlantic and Gulf coasts.
This turtle is named for the diamond patterns on its top shell. The diamondback terrapin's range is along the Atlantic and Gulf coasts, from Cape Cod to Texas. It is believed to be the only turtle in the world that lives exclusively in brackish-water areas. In these areas, such as tidal marshes, estuaries, and lagoons, the water contains some salt, but it is not as salty as the ocean.
The diamondback terrapin's shell is covered with scales or plates called scutes that bear deep, diamond-shaped growth rings. The top shell is light brown, gray, or black; the bottom shell ranges from yellow to olive. Black spots and wiggly marks, in a pattern unique to each turtle, appear on the reptile's whitish skin.
Female terrapins are much larger than males, averaging about 7.5 inches compared to 5 inches for the male. Females reproduce when they are between 8 and 13 years old. In the summer, they move from marsh creeks onto beaches and dunes to lay their pinkish-white eggs in 6-inch-deep nests in the sand. After 60 - 120 days, the inch-long hatchlings emerge from the nest and enter the nearest water.
While the diamondback terrapin eats snails, clams, crabs, and some marsh plants, the reptile's population was decimated in the 1700s and 1800s because its meat was considered such a delicacy - the chief ingredient in terrapin soup. While protective legislation is now in place, the terrapin's population has a long way to go to rebound from previous overharvesting.
Today, the diamondback terrapin is faced by a number of threats: destruction of its coastal marsh habitat; automobiles (that run over turtles crossing the road to lay eggs); boat propellers; and raccoons, muskrats, skunks, and crows that eat the turtle's eggs. While it is doubtful that the diamondback terrapin will ever recover from its decimation for terrapin soup, this fascinating reptile is making a comeback in some areas.
The word "terrapin" is derived from the Algonquian Indian word "torope" and is used to refer to a variety of North American aquatic turtles of the family Emydiolae, especially the genus Malaclemys. The diamondback terrapin is the state reptile of the state of Maryland and the official mascot of the University of Maryland.