Turtle

ReptileTestudinesShelled

Overview

Turtles are reptiles of the order Testudines, characterised by a bony or cartilaginous shell consisting of a domed upper carapace and flat lower plastron, into which most species can partially or fully retract head and limbs. The order includes sea turtles, freshwater turtles and terrapins, and the generally terrestrial tortoises.

Habitat & Range

Turtles occupy a remarkable range of habitats — open ocean, tropical rivers, North American hardwood forests, arid grasslands, and high-latitude wetlands. Sea turtles undertake very long migrations between feeding and nesting beaches. Tortoises are primarily terrestrial and often adapted to dry habitats.

Diet

Diet varies sharply between groups. Many sea turtles are herbivorous as adults (green sea turtles feed primarily on seagrass and algae) while others, such as leatherbacks, feed on gelatinous prey such as jellyfish. Freshwater turtles include omnivores and carnivores; tortoises are typically herbivorous. Specific diet should be confirmed by species-level reference.

Behavior

Turtles are typically long-lived, slow-developing animals with late sexual maturity and high adult survival. Many species lay eggs in nests dug on land or beach. Sex determination in many turtle species is temperature-dependent, with incubation temperature influencing the sex of hatchlings — a characteristic that makes some species particularly vulnerable to a warming climate.

Human Interaction & Conservation

Many turtle species are seriously threatened. Sea turtles face ongoing pressure from bycatch, plastic and other marine pollution, beach development, and climate change. Tortoises and freshwater turtles face habitat loss and illegal trade for the pet and food markets. Pet ownership of turtles is regulated in many jurisdictions; in the United States, sale of small turtles is restricted because of salmonella public-health concerns. Always verify legal and welfare guidance before acquiring a pet turtle, and work with an exotic-animal vet.

Similar Animals

Other reptiles include lizards, snakes, and crocodilians. The related groups within Testudines — tortoises, terrapins, and sea turtles — share the basic shelled body plan but differ substantially in ecology.