leatherback turtle sea turtles are the world ’s only “ warm - blooded ” reptiles , maintaining a core body temperature of about 26 degrees Celsius ( 79 degree Fahrenheit ) even as they dive into almost - freeze northern ocean weewee . According to new determination published inBiology Lettersthis calendar week , these turtles are able keep their leg warm thanks to bundles of arterial blood vessel and veins in their hips .
Like us , leatherbacks ( Dermochelys coriacea ) are endothermic , and like seals and seabirds , they have what ’s called vascular counter - current heat exchangers in their limb : Heat is transfer between close bundle of nervure and artery . But does this arrangement work in the same way in unlike animals?John Davenport of University College Corkand colleagues dissect six juvenile leatherbacks that were collected as by-catch on fishing vessel in the equatorial Pacific . ( A autopsy unwrap that they had overwhelm . ) The team analyse the vascular bundles in their bum and studied their human relationship with hind limb musculature and bod .
The closely bundle arrangement of veins and arteries at the nucleotide of the leg , the researchers found , have a counter - current function that ’s the opposite as that of aquatic mammals and raspberry exposed to similarly inhuman conditions . Rather than transfer heat from ( outgoing ) arterial blood to ( incoming ) venous blood to maintain noble-minded core body temperatures while the limb are kept nerveless , leatherback heat exchangers wield higher temperatures within their limb muscles .
Their body core temperatures are typically lower than that of their muscles , and their dateless amount of exercise – they ’re always swimming – transfer some heat to the insulated core . This system stay fresh sea turtle muscles warm enough to put to work effectively in the coldness . Leatherbacks are the sole living species of the family Dermochelyidae , which has a 50 - million - twelvemonth account of foraging in cool water .
Keeping heat in the muscleman ( and outside of the core ) is peculiarly important for nesting females , who use their legs for locomotion as well as nest digging ; otherwise , they ’d overheat .
