Diamondback terrapin;  Diamondback turtle

Carapace:  Gray, brown, and/or black;  contrasting dark and light diamond-like pattern.  
Head, legs, and plastron:  yellowish, off-white, or gray with black dots.
Hatchlings are brighter in color than adults.  
Prominent black eyes.
Hind feet are webbed.

Northern Diamondback Terrapin / Malaclemys terrapin terrapin:  Wedge shaped carapace;  Found from Massachusetts to North Carolina

Carolina Diamondback Terrapin / Malaclemys terrapin centata:  Carapace is wedge shaped and oval;  Found from North Carolina to the Atlantic coast of Florida.

Florida East Coast Diamondback Terrapin / Malaclemys terrapin tequesta:  Carapace is dark. Central area of scutes are lighter. Scutes of the upper portion of the shell do not have obvious growth rings;  Found on the Atlantic coast of Florida.

Mangrove Diamondback Terrapin / Malaclemys terrapin rhizophorarum:  Neck is striped. Hind legs are vertically striped;  Found in the Florida Keys.

Ornate Diamondback Terrapin / Malaclemys terrapin macrospilota:  Carapace scutes are large with orange or yellow splotches;  Found in the Florida Bay to Florida panhandle.

Mississippi Diamondback Terrapin / Malaclemys terrapin pileata:  Carapace is dark brown or black. Plastron is yellow. Legs are dark;  Found from western Florida to western Louisiana.

Texas Diamondback Terrapin / Malaclemys terrapin littoralis:  The highest point of the carapace is toward the rear. Plastron is off-white. Legs are greenish-gray with dark splotches;  Found from western Louisiana to western Texas.

Weight = up to 2 pounds;  Males measure 4-6 inches;  Females measure 6-9 inches

North American coast from Massachusetts to Mexico.

Salt or brackish water in coastal swamps and river mouths.

Solitary except when breeding.
During the day:  Most of this animal's time is spent in the water, although it also spends a lot of time basking.
At Night:  Most time is spent buried in the mud.
In Winter:  Depending on climate, the Diamondback terrapin may or may not hibernate in the mud.

Humans

Insects, fish, crustaceans, mollusks, worms, (water plants on very rare occasions.)

For more information, visit these other web sites:

Diamondback terrapin, Malaclemys terrapin by Mimi Loutrel and Marvin Cornett

Diamondback terrapins - North American Turtles - National Aquarium in Baltimore