Turtles

© Roger de la Harpe

Name

Turtles

Others in Family

Green turtle, Hawksbill turtle, Loggerhead turtle, Leatherback turtle

Scientific Name

Chelonioidea

Description

Green turtle (Chelonia mydas)
The green turtle can measure up to 1.5m in length. Its body has four lateral plates which do not overlap, located in a row on either side of its central line. Its snout is short and its bill unhooked. On its shell is a sunburst pattern.

Hawksbill turtle (Eretmochelys imbricata)
The hawksbill turtle measures up to 1m. It has two pairs of scales between its eyes and a rather long, hooked bill. Its carapace has serrated edges and its upper shell is marked in a speckled pattern.

Leatherback turtle (Dermochelys coriacea)
The leatherback turtle measures up to 2.5m, and is the fourth largest reptile. They have large, smooth shells with no plates, covered by black skin and no bony plates which cover their carapace. On the upper surface of their shells are seven longitudinal ridges. Their flippers are long and elongated with no claws.

Loggerhead turtle (Caretta caretta)
The loggerhead turtle measures up to 2m. Its head is prominent and large, and its reddish-brown shell has five pairs of shields along its central line. It has two pairs of claws on its flippers.

Behaviour

The Chelonioidea superfamily consists of 5 families of which 3 are extinct. All turtles breathe air and are powerful swimmers. Turtles can rest or sleep underwater for several hours. They have a salt gland on their head to dispel excess salt taken in with food. A lifespan of up to 80 years.

Breeding

Turtles mate at sea, but lay eggs on land. Up to 200 eggs are laid in a batch. 1-8 batches are laid during a season. Sex of hatchlings is determined by the sand temperature in the nest. Hatchlings make their own way back to the ocean. Unfortunately, only 0,2 % survive to maturity.

Diet

Turtles feed in water up to 50 m. They are omnivorous and feed on a variety of sponges, cnidarians, molluscs, crustaceans, algae, plants and fish. Jellyfish (cnidarians) are a favourite of sea turtles. Plastic bags are often mistaken for jellyfish and ingested by turtles, which often kills them.

Distribution

Occurs in all oceans of the world, except the Arctic ocean.

Common Species

Green turtle - Chelonia mydas
Hawksbill turtle - Eretmochelys imbricata
Leatherback turtle - Dermochelys coriacea
Loggerhead turtle - Caretta caretta

© Johan Boshoff