Leatherback sea turtle – Dermochelys coriacea
The leatherback sea turtle is a species in Order of testudines. Dermochelys coriacea is the only living species in the family of Dermochelyidae.
It is the largest of all living turtle species.
Description, Anatomy & Characteristics
Size & Weight
As the largest of all turtles, the leatherback sea turtle is up to 2.50m long and weighs 700kg. The largest turtle measured so far had a shell length of 256cm and weighed a proud 916kg.
In contrast to the sea turtles, the elongated shell of Dermochelys coriacea does not consist of patterned horn scales. Rather, it is a loosely connected bone armour with thick leather-like skin. It can be clearly seen that the back part consists of 7 long bone plates. The belly part consists of only 5 bone plates, which are also elongated.
The basic colour is dark blue to black, with the soft parts showing light spots. There is also an individual pink spot on the top of the head, the function of which is unknown. It is assumed that this is a light-sensitive sense which serves as orientation.
Habitat, Distribution & Occurrence
The leatherback sea turtle lives in the open sea.
Due to the fact that Dermochelys coriacea is mainly found in open water, it is rarely seen when scuba diving in the Canary Islands.
Reports about sightings
- in March 2012 a dead leatherback sea turtle washed up on the beach of Corralejo (Fuerteventura)
- in August 2015 a dead specimen of this species was found off La Graciosa (north of Lanzarote)
- on 15 November 2015 an injured turtle was found on the beach of Puerto de La Cruz (Tenerife)
- in November 2016 also a dead animal was discovered on the beach of El Chinchorro (Fuerteventura)
- on 14.05.2019 a dead leatherback sea turtle was spotted off the coast of Playa de Amadores (Gran Canaria)
It has the largest range of all turtles living in the water. It extends over tropical and suptropical seas and oceans, including the Mediterranean Sea. It can also be found in summer in the temperate and polar zones. This is only possible because it can keep its body temperature 18°C above the ambient temperature.
Feeding & Biology
Dermochelys coriacea is a food specialist and feeds mainly on jellyfish. They eat between 10 and 100 kg of jellyfish per day. Their diet also includes other soft species such as tunicates and cephalopods.
In spring the animals swim 5000km from tropical to temperate zones and return just in autumn. In 2012, a specimen was even found on the French Mediterranean coast bearing a Trinidad and Tobago identification mark. So it had travelled over 7000km. Record holder is an animal that swam 20000km in 647 days from West Papua to the USA.
It has been found that it rests only 0.1% of the day. So it can be called a permanent swimmer. It reaches speeds of more than 35km/h. This is a record among all reptiles.
When Dermochelys coriacea dives, it reaches depths of 1280m. An average dive lasts 3-8 minutes. However, times between 30 and 70 minutes were also measured.
Reproduction & Age
To the combination, the male embraces a female with its long front-flippers in the middle of the body. After mating the females crawl to sandy beaches to lay their eggs. Worldwide 64 nesting grounds are known.
Per nest a leather turtle lays between 50 and 100 eggs in a hole in sand. Then it scoops it up again and returns to the sea. After about 55 days the young hatch. Their sex depends on the temperature. While at 27 to 28.7°C more males hatch, at 29.7 to 32°C mainly females hatch. At birth they are on average 6.1cm tall with a weight of 46g.
Little is known about the age of Dermochelys coriacea. Estimates vary between 30 and 100 years.