lancet fish

noun, plural (especially collectively) lan·cet·fish, (especially referring to two or more kinds or species) lan·cet·fish·es.

1. any large, marine fish of the genus Alepisaurus, having daggerlike teeth.

noun

1. either of two deep-sea teleost fishes, Alepisaurus ferox or A. borealis, having a long body with a long sail-like dorsal fin: family Alepisauridae