Fatspine Spurdog

This small species of the 'megalops-cubensis group' is distinguished by the following characters: head width at mouth 9.9-11.3% TL; mouth width 2.1-2.4 times the horizontal prenarial length; direct pre-second dorsal length 3.7-4.2 times the pectoral-fin anterior margin, 2.6-2.8 times the dorsal caudal margin; preoral length 2.7-3.0 times the horizontal prenarial length, 8.3-9.2% TL; anterior nasal flap strongly bifurcate; first dorsal fin upright to raked; the exposed bases of dorsal-fin spines are very broad, 1.2-1.5% TL; both dorsal fins have short inner margins, first dorsal-fin height 1.3-1.7 times its inner margin length, second dorsal-fin height 1.1-1.3 times its inner margin length; pectoral-fin anterior margin 1.9-2.2 times its inner margin length; preventral caudal margin 2.4-4.6 times inner margin of pelvic fin; caudal fin pale with poorly demarcated, whitish posterior margin, caudal bar absent; flank denticles unicuspid; monospondylous centra 39-42 (mainly 40-41), precaudal centra 82-86, total centra 107-111 (mainly 109-110) (Ref. 58437).

Distinct pairing with embrace (Ref. 205).

Found at the lower continental shelf and upper continental slope (Ref. 58437).

Squalus crassispinus, the fatspine spurdog, is a dogfish of the family Squalidae, found on the continental shelf off the northern coast of Western Australia, at depths of 180 to 200 metres (590 to 660 ft). The length of the longest male specimen measured is 56 centimetres (22 in).

Squalus crassispinus is a rare, small and slender dogfish with a broad head and short snout. There is a broad, small medial barbel on the anterior nasal flaps. The pectoral fin has a shallowly concave posterior margin. The first dorsal fin is moderately high, and both dorsal fin spines are very stout.

Coloration is light grey above, paler below, with no white spots. The pale dorsal fins have dusky tips.

Its reproduction is ovoviviparous.