Leatherback sea turtles are the largest of all living turtles, a unique marine reptile. They stand apart from other sea turtle species due to their namesake shell. These highly migratory creatures traverse vast distances across the globe, inhabiting a wide range of ocean temperatures. Their impressive size allows them to explore diverse marine environments.
Weight of Leatherback Turtles
Adult leatherback turtles typically weigh between 550 and 1,540 pounds (250 to 700 kg). The largest recorded individual was an adult male found in Wales, weighing approximately 2,019 pounds (916 kg) and measuring over 8 feet in length.
Their substantial weight makes them the heaviest non-crocodilian reptile. Compared to other sea turtle species, leatherbacks are considerably larger. Green sea turtles, for instance, average between 150-419 pounds, with a maximum of 871 pounds, making them the third largest sea turtle species. Loggerhead sea turtles, the largest of the hard-shelled turtles, average 289 pounds and can reach a maximum of 1,200 pounds, still less than the largest leatherbacks.
Understanding Their Size
The immense size of leatherback turtles is supported by their specialized diet, primarily consisting of jellyfish. Despite the low nutritional value, leatherbacks consume vast quantities, sometimes nearly their own body weight daily, to sustain their large body mass and rapid growth. Their mouths contain backward-pointing spines that help them swallow and retain slippery prey.
Unlike other sea turtles, leatherbacks do not possess a hard, bony shell. Their carapace is covered by tough, rubbery skin stretched over a flexible matrix of dermal bones and cartilage-like tissues. This unique shell structure contributes to their weight and allows for flexibility, enabling them to withstand extreme pressures during deep dives. Their large body size and a thick layer of fat provide insulation, allowing them to maintain a warm core body temperature in cold waters, an adaptation for their deep diving and wide distribution.
Weight Through Their Life Cycle
Leatherback turtles begin their lives as hatchlings, weighing approximately 1.6 ounces (45 grams) and measuring about 2.4 inches in carapace length. They undergo a significant growth spurt, growing faster than hard-shelled turtles. Studies suggest their length can increase thirty-fold and their mass 6,000-fold from hatching to adulthood.
Juvenile leatherbacks exhibit rapid growth rates, with estimates ranging from 8.6 to 39.4 cm per year in carapace length. Females may reach sexual maturity between 9 and 20 years of age, with an average estimate of 13-14 years. Adult growth rates are slow, with most size differences established during their juvenile and subadult stages. Weight can fluctuate in adults based on factors such as food availability and reproductive cycles.