[4] The shortspine thornyhead has a large head with a strong spiny ridge, and an elongate, tapering body which grows to a maximum length of 80 cm (31 in).

The general color of this fish is bright red with varying amounts of black on the fins and a pale-colored gill chamber.

The young fish migrate to deeper water as they mature[6] Spawning occurs between December and May along the Pacific coasts of contiguous United States and between April and May in the Gulf of Alaska.

Allowing for an increased ventilation frequency during exposure to progressively hypoxic conditions, as compared to its more shallow relative Scorpaena guttata, enables S. alascanus to compensate for the inherent low concentrations of oxygen in the OMZ.

Further, heightened levels of lactate dehydrogenase, specifically the anaerobic isoform- LDH-A in the heart and muscles of S. alascanus, suggests an adaptive mechanism for ATP production during low oxygen availability.