Acanthonus
Bony-eared assfish
Species of fish
The bony-eared assfish (Acanthonus armatus) is a bathypelagic species of cusk-eel found in tropical and sub-tropical oceans at depths of from 1,171 to 4,415 metres (3,842 to 14,485 ft). It has been found as far north as Queen Charlotte Sound off British Columbia's coast.[7] This species grows to a length of 37.5 centimetres (14.8 in) SL.[6] The larvae are similar in overall form to the related gargoyle cusk, but have elongated 3rd, 4th, and 5th pectoral-fin rays[8]
The bony-eared assfish may have the smallest brain-to-body weight ratio of any vertebrate.[9]
Like many other creatures that dwell in the depths of the sea, assfish are soft and flabby with a light skeleton. This is likely to have resulted from a lack of food and the high pressures which accompany living at such a depth, making it difficult to generate muscle and bone.[10]