Diamondback terrapin

Malaclemys terrapin

Species Information
Exhibit Name and Location Maryland: Mountains to the Sea, Tidal Marsh – Main Aquarium, Level 2
Description of Animal Diamondback turtles have concentric, somewhat diamond-shaped markings and grooves on the scutes (plates) of their carapace (top shell), which ranges from medium gray or brown to nearly black in the subspecies exhibited at the Aquarium. Skin color ranges from pale to dark gray or black, flecked with dark spots, blotches or stripes. The hingeless plastron (bottom shell) is yellow to green or black and may be marked with dark figures and blotches. The feet are strongly webbed; the hindfeet are especially large and flat. Mating takes place in the spring, with nesting extending through mid-summer. Diamondbacks hibernate during the cold winter months buried in the mud.
Aquarist's Note The Diamondback terrapin is the only species of turtle in North America that spends its life in brackish water (salty but less so than sea water). At the Aquarium, the Salt Marsh exhibit is filled with brackish water, which is essential for the fish in this exhibit and is better for the health of the turtles. (Diamondbacks kept for prolonged periods in fresh water often develop shell infections.) Although diamondbacks are highly aquatic, in the wild they often bask on logs during warm weather. The water temperature in the Salt Marsh exhibit is sufficiently warm that the turtles rarely leave it to sit on their basking log, which is warmed by a hidden, overhead light.
Diet Diamondbacks are well adapted for eating hard-shelled prey including aquatic snails, crabs, and small bivalves (e.g., blue mussels). They also eat carrion, fish, marine worms, and plant material.
Size Adult males are significantly smaller than females in weight and carapace length. Males range from 4 to 6 inches (10 to 14 cm) in length, and females from 6 to 9 inches (15 to 23 cm). Females also have wider heads, deeper (taller) shells, and shorter tails than males.
Range Diamondbacks live in coastal salt marshes, estuaries, and tidal creeks along the U.S. Atlantic and Gulf coasts from Cape Cod, Massachusetts, to western Texas, including the Florida Keys. This range is occupied by 7 subspecies with some overlap in their distribution. The subspecies exhibited at the Aquarium, the northern Diamondback (Malaclemys terrapin terrapin), ranges from Cape Cod to Cape Hatteras, North Carolina.
Population Status The status of the northern diamondback is unknown. The population in the Chesapeake Bay is currently under review by the Maryland Department of Natural Resources. In some areas, terrapins appear to be in decline due to many factors—destruction of nesting beaches, excessive predation by raccoons, and large-scale commercial harvesting for meat. Many terrapins drown in eel and crab pots. These deaths could be prevented by equipping the pots with turtle excluders, or “Bycatch Reduction Devices,” as required by law in Maryland. The Maryland Department of Natural Resources (1-800-688-FINS) provides information on how to make excluders. These simple devices can also be purchased at many bait shops.
Predators Nesting terrapin females are vulnerable to predation by raccoons. Eggs and hatchlings are preyed upon by a wide variety of animals including crabs, crows, gulls, rats, muskrats, foxes, raccoons, skunks, and mink. Terrapin eggs also are destroyed by the invasion of introduced beach grass. Survival rates during the first year are estimated as low as 20%.

Species Information

Exhibit Name and Location
Maryland: Mountains to the Sea, Tidal Marsh – Main Aquarium, Level 2

Description of Animal

Diamondback turtles have concentric, somewhat diamond-shaped markings and grooves on the scutes (plates) of their carapace (top shell), which ranges from medium gray or brown to nearly black in the subspecies exhibited at the Aquarium.

Skin color ranges from pale to dark gray or black, flecked with dark spots, blotches or stripes. The hingeless plastron (bottom shell) is yellow to green or black and may be marked with dark figures and blotches.

The feet are strongly webbed; the hindfeet are especially large and flat.

Mating takes place in the spring, with nesting extending through mid-summer.

Diamondbacks hibernate during the cold winter months buried in the mud.

Aquarist's Note

The Diamondback terrapin is the only species of turtle in North America that spends its life in brackish water (salty but less so than sea water).

At the Aquarium, the Salt Marsh exhibit is filled with brackish water, which is essential for the fish in this exhibit and is better for the health of the turtles. (Diamondbacks kept for prolonged periods in fresh water often develop shell infections.)

Although diamondbacks are highly aquatic, in the wild they often bask on logs during warm weather.

The water temperature in the Salt Marsh exhibit is sufficiently warm that the turtles rarely leave it to sit on their basking log, which is warmed by a hidden, overhead light.

Diet
Diamondbacks are well adapted for eating hard-shelled prey including aquatic snails, crabs, and small bivalves (e.g., blue mussels). They also eat carrion, fish, marine worms, and plant material.

Size

Adult males are significantly smaller than females in weight and carapace length.

Males range from 4 to 6 inches (10 to 14 cm) in length, and females from 6 to 9 inches (15 to 23 cm).

Females also have wider heads, deeper (taller) shells, and shorter tails than males.

Range

Diamondbacks live in coastal salt marshes, estuaries, and tidal creeks along the U.S. Atlantic and Gulf coasts from Cape Cod, Massachusetts, to western Texas, including the Florida Keys.

This range is occupied by 7 subspecies with some overlap in their distribution. The subspecies exhibited at the Aquarium, the northern Diamondback (Malaclemys terrapin terrapin), ranges from Cape Cod to Cape Hatteras, North Carolina.

Population Status

The status of the northern diamondback is unknown. The population in the Chesapeake Bay is currently under review by the Maryland Department of Natural Resources.

In some areas, terrapins appear to be in decline due to many factors—destruction of nesting beaches, excessive predation by raccoons, and large-scale commercial harvesting for meat.

Many terrapins drown in eel and crab pots.

These deaths could be prevented by equipping the pots with turtle excluders, or “Bycatch Reduction Devices,” as required by law in Maryland.

The Maryland Department of Natural Resources (1-800-688-FINS) provides information on how to make excluders. These simple devices can also be purchased at many bait shops.

Predators

Nesting terrapin females are vulnerable to predation by raccoons. Eggs and hatchlings are preyed upon by a wide variety of animals including crabs, crows, gulls, rats, muskrats, foxes, raccoons, skunks, and mink.

Terrapin eggs also are destroyed by the invasion of introduced beach grass. Survival rates during the first year are estimated as low as 20%.