Chelonia mydas

Chelonia mydas Linnaeus 1758

Common Names

Green Turtle (English), سلحفاة بحرية خضراء (Arabic)

Languages: English

Overview

Description

A large marine turtle, reaching up to 1,200 mm in carapace length; largest Egyptian specimen is 1,190 mm. Carapace depressed, rounded, smooth; scutes juxtaposed; posterior edge without indentations; 4 coastal scutes; first marginal scute in contact with first vertebral scute. Head relatively small with a single pair of prefrontals. C. mydas differs from all other marine turtles in possessing serrations on the lower jaw, which facilitate grazing on marine grasses. Forelimbs and hind limbs have a single claw each. Males smaller, with longer tails and larger claws. Color of carapace light brown with dark streaks radiating out from a point at the posterior margin of each scute. Dorsal sides of limbs and head brown, each scale edged yellowish. All ventral sides whitish yellow.

Conservation

Conservation Status

Endangered

Status in Egypt

Uncommon, localized and declin­ing. Facing a variety of threats in Egypt, most importantly as a by-catch of commercial fishing vessels. The species along with other marine tur­tles are consumed in some Egyptian coastal cities. Loss of nesting beaches is also a problem particularly in the Red Sea.

Description

Behaviour

Herbivorous, feeding largely on marine grasses and algae when adult; young carnivorous, pelagic.

Ecology and Distribution

Global Distribution

Circum-global, largely within the 20°c oceanic isotherms.

Distribution in Egypt

Known from Egyptian waters in both the Mediterranean and Red Sea. The only reliable evidence of nesting on the Mediterranean shores is a nest with eggs found near Zaranik, North Sinai, in the summer of 1998 (Clarke et al. 2000). A dead juvenile (carapace length 85 mm) found at Baltim could have originated from elsewhere. Dead individuals are frequently encountered throughout the Egyptian Mediterranean shoreline. In the Red Sea the species has been recorded from both the Gulfs of Suez and Aqaba, and has been reported to have nested at Ras Sharatib, south of Abu Rudeis (where some 80 females were estimated to nest),Tiran Island, Qulan Islands, Wadi El Gemal Island, Ras Banas, and Zabargad Island. Eggs and embryos from Giftun El Kebir Island referred to this species by Marx (1968), were re-identified as Eretmochelys imbricata by (Frazier and Salas 1984). The species nests sporadically along the mainland shores of the Red Sea south of Marsa Alam, where almost a hundred nests have been found between Ras Baghdadi and Marsa um El Abbas.

Habitat

Warm marine waters. Frequently segrass beds, which by nature are in fairly shallow, sandy, inshore habitats. Often near wadi deltas (In the Red Sea), where the fringing reef is broken and suitable sandy substrate in shallow waters is available. Generally, the availability of suitable seagrass beds is limited in the Egyption Red Sea, and apparently so in the Mediterranean as well, given the small number of records in Egyption territory. Nesting in the Red Sea has been recorded in the months of June and July. Sexual maturity reached between 12 and 50 years, depending on location and nutritional history.

Taxonomy

  • Testudo mydas Linnaeus, 1758 (synonym)
  • Chelonia mydas Schweigger, 1812; Flower, 1933; Marx, 1968; Saleh, 1997 (synonym)

References

S., Baha El Din. (2006).  A Guide to the Reptiles and Amphibians of Egypt, The American University in Cairo Press, Cairo..