The Bigeye Sixgill Shark (Hexanchus nakamurai) owes its name, obviously, to the fact that it is a rare six gill shark as apposed to the regular five gill slits and too its rather large green eye.
The bigeye sixgill shark exact range isn’t really known and it is believed that it probably lives in areas outside of its known range. It has been caught from Mexico to the Bahamas, Cuba, Nicaragua, and Costa Rica. In the eastern Atlantic it has been caught from France south to Morocco and the Mediterranean Sea. It is also found in the Indian Ocean, off the eastern and southern coasts of the Africa plus Japan, Taiwan, Philippines, New Caledonia, and Australia.
The bigeye sixgill sharks limited known range is probably mainly due to the depths that it lives at, typically 300-2000 feet. Usually towards the deep end of this spectrum except for when it moves upwards to feed.
Lack of a forward dorsal fin, large green eye, six gill slits and the position of its only top fin are its best identification characteristics.