The Roughskin dogfish, Centroscymnus owstoni, is a sleeper shark of the family Dalatiidae, found circumglobally on continental shelves in tropical, subtropical and temperate seas, at depths of between 328.08 and 4921.26 ft (100 and 1,500 m). It reaches a length of 3.94 ft (120 cm).
The Roughskin dogfish has two dorsal fins of approximately equal size and shape with a small spine in front of each, and a long pointed snout.
The teeth are one of the main ways of distinguishing this species from the similar Longnose velvet dogfish and Plunket shark. The lanceolate upper teeth of the roughskin dogfish are narrow-based with expanded spear-like tips, and the lower teeth are broadly triangular with the point obliquely skewed away from the centre of the jaw.
Coloration is black or blackish brown.
The Roughskin dogfish is ovoviviparous with 16 – 28 young in a litter.
It feeds mainly on fish and cephalopods.
The flesh is high in mercury, and is utilized as fishmeal and a source of squalene.
Illustration by Dr Tony Ayling