Diamondback Terrapin

Overview

The Diamondback Terrapin is a unique, medium-sized turtle specifically adapted for life in brackish and saltwater environments. Unlike most other turtles, it spends its entire life cycle within coastal salt marshes, estuaries, and tidal creeks along the Atlantic and Gulf coasts of the United States.

Distribution & habitat

These turtles are found in estuarine habitats ranging from Cape Cod, Massachusetts, to Corpus Christi, Texas. They favor reedy marshes, tidal flats, and mangrove-lined coastal waters. While they thrive in saline environments, they require access to fresh water for drinking.

Appearance

Named for the distinct, diamond-shaped concentric rings on their carapace scutes, these turtles exhibit significant color variation, ranging from gray and brown to nearly black. They show strong sexual dimorphism; females are significantly larger than males, possessing wider heads and shorter tails. Their skin is typically gray or light green with dark flecks, and they often feature a dark, mustache-like marking on the upper jaw.

Biology & behavior

Diamondback Terrapins are essential to the health of salt marsh ecosystems, acting as keystone predators that help regulate snail populations. They exhibit high site fidelity, with adults often remaining within the same tidal creek for their entire lives. While they are tolerant of one another, they face significant threats from habitat loss, road mortality, and accidental drowning in fishing gear.

Feeding

Their diet consists primarily of estuarine invertebrates, including small crabs, bivalves, and snails. They may also consume small amounts of plant matter and algae.