Blackfish

Backfish is a name given to any of a number of fish having dark colour. The term is also applied for pilot whale. A salmon, just after spawning, is called a black fish. Some of the notable balckfishes are: a large fish of rivers in Australia, zoological name Gadopsis marmoratus belonging to the family Gadopsidae; an open-ocean fish related to the perches belonging to the genera Centrolophus and Schedophilus, and the family Centrolophidae, the large and widespread Centrolophus niger in particular; and a small fish of Arctic coasts of Alaska and Siberia that withstand feezing, zoological name Dallia pectoralis, belonging to the family Umbridae.