Featured Elasmobranch

October 2004

ROUGHTAIL SKATE

BATHYRAJA TRACHURA (GILBERT, 1892)

FAMILY ARYNCHOBATIDAE (SOFTNOSE SKATES)

Identification: A medium-sized skate, with a flexible rostrum, a dorsal surface covered with smaller prickles, a median row of 15-34 tail thorns, but no interdorsal thorn; ventral surface smooth, without prickly or thorns. Both the dorsal and ventral surfaces are a uniform plum brown to black, with lighter patches on the ventral surface, and around the mouth, gill slits, and pelvic lobe tips.

Size: Maximum reported length 89.0 cm for females and 90.0 cm for males

Distribution: Eastern North Pacific, from the Sea of Okhotsk to the Bering Sea, Gulf of Alaska and southward to northern Baja California.

Habitat: A deep dwelling skate found at depths of 400 to 2,550 m.

BiologyA little known skate that is occasionally taken as a bycatch in deepsea trawl fisheries. There is no directed fishery for this skate. The systematics of the roughtail skate and several other softnose skates from the eastern North Pacific are under investigation by researchers at Moss Landing Marine Laboratories.

General interest: A little known skate that is occasionally taken as a bycatch in deepsea trawl fisheries. There is no directed fishery for this skate. The systematics of the roughtail skate and several other softnose skates from the eastern North Pacific are under investigation by researchers at Moss Landing Marine Laboratories.

By Chante Davis

Pacific Shark Research Center, Moss Landing Marine Laboratories
8272 Moss Landing Road, Moss Landing, CA 95039
cdavis@mlml.calstate.edu