Diamondback Terrapin
Why in News?
Diamondback Terrapin is in the news because a rare two-headed (bicephalic) hatchling was discovered on Cape Cod, Massachusetts.
Habitat and Distribution
- The Diamondback Terrapin is the only North American turtle species exclusively adapted to brackish water.
- It inhabits the Atlantic and Gulf coasts of the United States, from Cape Cod to Texas, and Bermuda.
- Its habitats include salt marshes, mangroves, tidal flats, lagoons and coastal creeks.
Appearance and Adaptations
- It is named after the diamond-shaped concentric patterns on its upper shell.
- Distinctive skin markings help identify individuals.
- Webbed feet aid swimming, while specialised salt glands help excrete excess salt.
- Females are larger (6–9 inches) than males (4–5 inches).
Diet and Behaviour
- It is carnivorous, feeding on snails, crabs, clams and mussels.
- By controlling marsh snail populations, it helps protect salt-marsh vegetation.
- Northern populations hibernate in marsh mud during winter.
Reproduction
- Nest temperature determines hatchling sex; warmer nests generally produce females.
- Females lay 4–25 eggs in sandy nests, mainly during June–July.
- Hatchlings emerge around August–September and face predation from foxes and raccoons.
Threats and Conservation
- Major threats include drowning in crab traps, habitat destruction, sea-level rise and illegal wildlife trade.
- Historically, overharvesting for turtle soup severely reduced populations.
- The species is classified as Vulnerable on the IUCN Red List.
- Bycatch Reduction Devices (BRDs) prevent terrapins from entering crab traps, substantially reducing accidental deaths while maintaining crab harvests.
