Green Sea Turtle
Chelonia mydas

Hawksbill Sea Turtle
Eretmochelys imbricata

Loggerhead Sea Turtle
Caretta caretta

Pacific Black Sea Turtle
Chelonia mydas agassizii

Chelonlid Sea Turtles of the Family Cheloniidae are reptiles that breath air with lungs, have scales, and have a three-chambered heart. Like other turtles and tortoises, they are in the Order Testudines, meaning that they have a hard, bony, upper (carapace) and lower (plastron) shell covering their body. Their ribs and vertebrae are fused to the carapace. They have beaks instead of teeth, lay eggs, and they have four legs for walking or swimming. Sea Turtles are the only turtles whose front legs are stronger than their rear legs. The legs are modified into paddles to assist with swimming. Their legs cannot support their body weight on land. Sea Turtles fall into 1 of 2 families – Cheloniid Sea Turtles of the Cheloniidae Family and Leatherback Sea Turtles of the Dermchelyidae Family. Cheloniid Sea Turtles have hard plates (scutes) covering their shells that are made from a substance similar to the main component of cattle horns. Their shells are oval or slightly heart-shaped and are low to reduce drag through the water. Leatherbacks have a leathery skin that covers the Plastron and Carapace, and strong, tuberculate, ridges running the length of the shell. Unlike most turtles, Sea Turtles cannot retract their head into their shell. Sea Turtles lack external ears but have eardrums covered by skin and have good hearing, especially in the lower frequencies. They have a very good sense of smell and good underwater eyesight. In air, they are nearsighted. Sea Turtles have cardiovascular systems that are adapted so that they can spend prolonged periods of time underwater. They spend the great majority of their life at sea but must come ashore to lay eggs. Cheloniid Sea Turtles are large, with the largest having a carapace length of 2.13 m (7 feet 2 inches).

Cheloniid Sea Turtles spend the majority of their time in shallow water to obtain access to air for breathing but can dive to depths in excess of 290 m (960 feet). They are omnivores that consume algae, cnidarians, crustaceans, fish, mollusks, plants, and sponges. In turn adult Sea Turtles are preyed upon by crocodiles, groupers and sharks. While ashore laying eggs, the females are preyed upon by coyotes, wild dogs, jaguars, and other large predator mammals. Their eggs are also vulnerable to these species, as well as shore birds, insects, and small mammals. Newly hatched juvenile sea turtles are prey for a wide variety of birds, fish, invertebrates and mammals. They lay large numbers of eggs multiple times a year and are long lived which helps to offset the large loss of their eggs and juveniles.

Cheloniid Sea Turtles are found worldwide in temperate and tropical seas. There are 6 known species in the Cheloniidae Family with 3 species being found along Mexico’s Pacific Coast.