Leatherback Sea Turtles- VS

Ectothermic Animals- Leatherback Sea Turtles

Ectothermic animals are those that rely on heat derived from external heat sources to warm up their bodies. Therefore, they cannot maintain a constant body temperature through internal metabolic processes.

Cold environment thermoregulation

In the winter season when temperatures decrease so does an ectothermic animal’s body temperature, where it may not be able to function properly. Turtles have evolved to survive these conditions by hiding underneath logs or rocks at the bottom and sleep during the winter. However turtles need to come to the surface to take in oxygen and breath, hence when hibernating they have evolved to use their cloaca. This is a posterior opening for the intestinal, reproductive and urinary systems, to absorb oxygen from the water. The cloaca has lots of blood vessels and absorbs enough oxygen for the turtle’s needs, which are quite low when sleeping in cold water.

Leatherbacks adaptations in cold environments

In particular Leatherback Sea Turtles have a low surface area to volume ratio and their core temperature changes at a slower rate this mean their less affected by an environmental change. In cold water they have adapted by increasing their flipper stroke frequency. This increased movement of the extremities means more heat is produced which increases their body temperature. At the same time the turtle’s circulatory system decreases blood flow to the extremities and stores heat in the core by a network of arteries and veins called counter current heat exchangers. This works by heat from blood in the arteries flowing from the core to extremities, being transferred to the blood flowing through the veins which lead back to the turtle’s core. Furthermore they have a layer of brown adipose tissue which is an insulating fat layer decreasing heat loss and helping to regulate temperature, due to its ability to keep 90% of heat.

Leatherbacks adaptations in warm environments

In high temperatures the turtle has also evolved to regulate its temperature by decreasing flipper stroke frequency, where blood flows to the extremities rather than being transferred to the core and the heat is lost through non-insulated tissue. Leatherback sea turtles are adapted to efficiently regulate their body temperature, where that they can maintain their temperature at 18 degrees or above that of their environments.