Latin name

Myoxocephalus quadricornis

Other name

Myoxocephalus quadricornis

Identification

The fourhorn sculpin has a large, lumpy head with protruding lips and four bony protuberances. Vertebrae: 37-42. Identified by four bony protuberances on the top of the head (smaller in females and juveniles and absent in freshwater species), a chain-like lateral line, sharp spines on the tarsus, and absence of palatal teeth. Gill stamens reduced to rounded, spiny projections. The soft dorsal part of adult males is often greatly enlarged; the caudal part is truncated and slightly rounded. 

Features of fish fins

Dorsal spines (total): 7 - 9; Dorsal soft rays (total): 13 - 16; Anal spines: 0; Anal soft rays: 13 - 17.

Pectoral fins are large and rounded. Freshwater species resemble the Alpine and European gobies, but differ in that the dorsal and anal fins terminate further forward, increasing the length of the tail. 

Fish colouring

Juvenile fourhorn sculpins are gray above, with three or four dark saddles under the dorsal fins and a dark spot on the dorsal side of the caudal fin. Adults are darker, with the spiny dorsal fin covered in black dust, and the soft dorsal, anal, pectoral, and caudal fins have dark stripes. The pelvic fins are pale.

Distribution

Widespread mainly in brackish Arctic coastal waters of Canada, Greenland, Russia and Alaska, and as a relict in the boreal Baltic Sea. Freshwater populations also occur in lakes in Norway, Sweden, Finland and Karelia, and in Arctic Canada (Nunavut and Northwest Territories).

Habitat

A bottom-dwelling fish that prefers brackish water. Depth range from 0 to 100 meters. 

Size

In the sea this fish grows to 20-30 cm (8-12 inches), but in lakes it rarely exceeds 15 cm (6 inches). Fourhorn sculpin weigh up to 260 g. Maximum reported age: 14 years.

Behavior

Found in cold, brackish to moderately brackish waters near the coast. Occurs in coastal rivers and may be found up to 120 miles inland. Benthic species. Movements are limited to short seasonal shore-to-shelf movements and mass movements of juveniles in shallow water in the fall. No mass migrations, movement into freshwater and long distances upriver are made by relatively few individuals at a time. It is diurnal from November to April, but predominantly nocturnal the rest of the year. 

Food and feeding habits

It feeds on small crustaceans, fish, mollusks and eggs. 

Reproduction

Breeds in winter, from November to March. Spawning takes place in shallow water, the male digs a depression in the gravel where mating and spawning take place. In spring they move to deeper waters where they remain for the summer.) Inland populations are locally threatened.

As the spawning season approaches, males become territorial and aggressive toward other males. Two to three days before spawning, females become restless and swim between short rest periods. When the female swims over the male, he rocks from side to side and raises his spiny dorsal fin; when the female stops near the male, he approaches her with a series of short jerks. Then both rhythmically wave their pectoral fins, forming an opening. The pair lies side by side with the male's caudal fin bent under the female's caudal fin. The male makes rhythmic tail movements towards the female, and these movements appear to stimulate her to lay eggs.

Fishing

The flesh is edible, but the species has no commercial value.

Relationship with a person

Harmless.