English name: THORNYHEAD ROCKFISH （Idiot Fish）

Scientific name: Sebastolobus alascanus

Origin: North Pacific Ocean (main fishing grounds: Alaska, USA)

Overview

THORNYHEAD ROCKFISH — also known as "idiot fish" or "idiot cod" for its characteristically large head and eyes — is a deep-water marine fish in the family Sebastidae. Despite the "cod" 

in its common name, it is not a true cod, but a scorpionfish relative native to the North Pacific.

Distribution & Habitat

The species occurs across the North Pacific, from northern California through the Gulf of Alaska and the Bering Sea to the Kamchatka Peninsula. It is a deep-water demersal fish, 

typically found at depths of 100 to 1,000 meters, often associated with rocky bottoms and low-oxygen (oxygen minimum zone) environments.

Physical Description

Adults reach a maximum length of about 80 cm (31 in). Key identifying features include:

- Large head with prominent spiny ridges

- Elongated, tapering body

- Dorsal fin with 15–17 spines and 8–9 soft rays

- Anal fin with 3 spines and 4–5 soft rays

- A distinctive deep notch in the pectoral fin

- Rounded caudal fin

- Bright red body coloration with variable black markings on the fins

Biology

Shortspine thornyhead is a long-lived species. It is well adapted to the cold, low-oxygen conditions of the deep continental slope, with physiological specializations that allow it to 

thrive where other fish cannot.

 Commercial Importance

Shortspine thornyhead supports significant commercial fisheries, with the largest landings in Alaska (USA) and the Russian Far East. The flesh is firm, white, and mild in flavor, 

making it versatile for a range of culinary applications. It is most commonly marketed frozen, either whole or as fillets.