The shortspine thornyhead (Sebastolobus alascanus) are distinguished from other
rockfishes by the spiny ridge across their cheek. They normally have 16 dorsal spines, while other rockfishes usually have 13
(longspine thornyheads have 15
spines). The shortspine differs from the longspine thornyhead by the
absence of an elongated third dorsal spine, having deeper notched and lighter-colored pectoral fins, and a gill chamber that
is light rather than dark. Shortspines are usually red or orange-red and often have white patches on their sides, back, cheeks,
and spiny dorsal fin tips when seen underwater. Their fins can have black patches and there may be dark spots or speckles on
their sides. An all-black female shortspine was reported in the waters off Oregon. The shortspine can grow up to 32 inches
(80 cm) in length.
Shortspine thornyheads have been found in the northern Bering Sea at common depths of 495
ft. to 1,485 ft. (150-450 m). Their range
extends as far south as Japan and Baja California, where they are commonly found at deeper depths of 3,300 ft. (1,000 m),
probably due to the warmer water temperatures. The name alascanus refers to Alaska, where scientists first captured
these fish. Shortspines can live between 80-100 years, making them one of the longest-lived fishes in the world. In contrast
to viviparous (“live bearing”) rockfishes, thronyheads are oviparous; producing eggs, rather than giving birth to small fishes.
Adult shortspines prey on a variety of other fishes and invertebrates, including shrimps and amphipods.
The commercial fishery for shortspine thornyheads has grown over the last several decades, especially along the
Pacific coast due to the development of a North American export market to Japan. Shortspines are occasionally
caught in recreational fisheries.
Adapted from Butler, J., and M. Love. 2002 Sebastolobus alascanus, p. 115-116. In
M. S. Love, M. Yoklavich, and L. Thorsteinson, The rockfishes of the northeast Pacific. Univ. California Press.