Dermochelys coriacea

Leatherback turtle

Dermochelys coriacea
(Vandelli, 1761)

Leatherback turtle (US Virgin Islands). credit: U.S. Fish and Wildlife Service (Claudia Lombard) <a href="https://creativecommons.org/licenses/by/2.0/deed.en">CC BY 2.0</a>
Image attribution
Leatherback turtle (US Virgin Islands). credit: U.S. Fish and Wildlife Service (Claudia Lombard) CC BY 2.0
Herpetofaunal category
Marine Reptiles
Species complex
Conservation Status
Non-resident Native - Migrant (IUCN - Vulnerable)
Previous scientific names
Chelonia lutaria,
Dermatochelys coriacea,
Dermatochelys porcata,
Dermochelis atlantica,
Dermochelys schlegelii,
Sphargis angusta,
Sphargis coriacea,
Sphargis mercurialis,
Testudo arcuata,
Testudo coriacea,
Testudo lyra,
Testudo tuberculata,
Common names
Leatherback turtle,
Leatherback sea turtle
Leathery turtle
Luth

Length: Generally, 1.2-1.6m, but some individuals up to 2.5 m.

Weight: up to 900 kg

Description

This beautiful species is the worlds largest turtle, and one of the heaviest reptiles on earth (exceeded only by some crocodilians). They are characterised by a large leather-like shell with longitudinal ridges, dark grey and white mottled skin, and enlarged forelimbs.
 

Identification

Distinguished from other marine turtles by its size, and large leathery shell. Juveniles are more heavily mottled than adults.
 

Distribution

The most wide-ranging of all marine turtle species being found in the tropical, and temperate regions of the Pacific, Indian, and Atlantic oceans. They often make excursions into the colder waters, reported as far north as Alaska, and in the waters south of Stewart Island.
Widespread in New Zealand with reports from all along our coastline, including the Chatham Islands.
 

Diet

Soft-bodied prey including jellyfish, tunicates and salps.
 

Ecology and habitat

The leatherback turtle is a species that spends the majority of its life in the open ocean. Its activity is influenced by the occurrence of its prey (jellyfish) in the water column, feeding at depth during the day, and near the surface at night. They are able to maintain their body temperature well above ambient water temperatures, which allows them to dive deeper (up to 1,280m), and occur in cooler water than any other marine reptile.
 

Life expectancy

For the most part unknown, but at least 30 years. Upper estimates suggest 100 years or more.
 

Social structure

Solitary, but females congregate at nesting grounds.
 

Breeding biology

Leatherback turtles do not breed in New Zealand.
Females congregate at nesting sites where they lay 30-150 soft-shelled eggs into deep holes that they dig with their large flippers. Eggs hatch after 60-80 days.
 

Disease and threats

The leatherback turtle is a host for many of the parasites, and diseases present in other marine reptiles, none of which pose a significant risk to the survival of the species. Of more concern are the many human-induced issues, resulting from the contamination of their habitat. The most significant being the consumption of marine plastics which bear a striking resemblance to the jellyfish, and other soft-bodied creatures which they primarily prey upon. Boat-strike, light pollution, exploitation of animals and eggs for food, as well as mortality as bycatch represent additional threats to their survival.
 

References

Doyle, T. K., Houghton, J. D., O’Súilleabháin, P. F., Hobson, V. J., Marnell, F., Davenport, J., &amp; Hays, G. C. (2008). Leatherback turtles satellite-tagged in European waters. Endangered Species Research, 4(1-2), 23-31.

Gill, B. J. (1997). Records of turtles and sea snakes in New Zealand, 1837–1996. New Zealand Journal of Marine and Freshwater Research, 31(4), 477-486.

Greer, A. E., LAZELL, J. D., &amp; WRIGHT, R. M. (1973). Anatomical evidence for a counter-current heat exchanger in the leatherback turtle (Dermochelys coriacea). Nature, 244(5412), 181-181.

Houghton, J. D., Doyle, T. K., Wilson, M. W., Davenport, J., &amp; Hays, G. C. (2006). Jellyfish aggregations and leatherback turtle foraging patterns in a temperate coastal environment. Ecology, 87(8), 1967-1972.

van Winkel, D., Baling, M., Hitchmough, R. 2018. Reptiles and amphibians of New Zealand – a field guide. Auckland university press, Auckland New Zealand.