Swordfish - AD

Background
Swordfish are ectothermic animals that live in tropical and temperate waters of the Atlantic, Pacific and Indian Ocean. They can be found from near the surface of the water to an astonishing depth of 550m. These marine animals typically reach 3m. The swordfish has earned its name due to its extremely long, flat, sword-like bill which is used to impale its prey. Adult swordfish are scaleless and possess no teeth and it is known that female swordfish live longer than the males.

Thermoregulation
Instead of using large amounts of energy to heat the whole body, swordfish warm only their eyes and their brains. They have special muscles adjacent to their eyes (that produce heat) and act as a thermostat. These muscles also help to maintain delicate nerve functions which are important when looking for prey. Furthermore, the muscles are rich in mitochondria and Cytochrome C and is supplied with blood through a vascular heat exchanger. It protects the CNS from rapid cooling during the daily vertical excursions. This is the reason why swordfish are able to swim in warm waters as well as waters where the temperature is close to freezing. The swordfish have an obvious advantage of having better vision for looking out for prey as well as a vast range of places to look for food.