Kingdom: Animalia

Phylum: Chordata

Class: Actinopterygii

Order: Scorpaeniformes

Family: Cyclopteridae

Genus: Cyclopterus

Species: C. lumpus

Physical Description

The body of lumbsuckers are compressed, deep anteriorly. Head relatively small, less than 5 in standard length.  Gill openings large, extending below level of upper pectoral fin ray. First dorsal fin present but covered by thick layer of skin forming a characteristic high crest with embedded spines. Bony tubercles present, arranged in 3 widely separated rows of large flattened tubercles on each side of body. Gill openings large, extend- extending below level of upper pectoral fin ray. Pyloric present 36-79. Ventral sucking disc formed by the modified pelvic fin. The ventral fins of the lumpsucker are modified to form a suction disc used to cling to rocky substrates. The skin is coloured slate grey to blue and is scaleless. Small bony lumps cover the body, with lateral rows of larger bony thorns along the body. The dorsal fin is situated behind a distinct dorsal ridge that is taller in the females. Adults grow between 30-50 cm in length. The body colour is variable, usually bluish-grey, yellow-green or yellow-brown. Spawning males are reddish on sides, fins and ventral surface.

Biology and Behavior

Basically solitary rather than a schooling fish. They exhibit a homing instinct. Adults inhabit rocky bottoms but may occur among floating seaweed. They migrate considerable distances in an annual cycle between deeper waters in winter and shallower waters in summer. Maximum depth reported at 868 m. Epibenthic-pelagic. Juveniles are found among algal clumps in bays and fjords moving offshore as they mature. During the spawning season the males become reddish in color on the underside, whereas females turn blue-green. Adults feed on ctenophores, medusas, small crustaceans, polychaetes, jelly fish and small fishes. Valued for their eggs, which make an inexpensive caviar. Eaten in Nordic countries, marketed fresh or smoked. Male flesh is most demanded and roe is sold fresh. Spawning takes place in the spring, after which males protect eggs in shallow inshore waters for six to ten weeks. Females of this species can reach 13 years of age and most begin spawning at four to five years of age Eggs are laid in large numbers on stony bottoms. Male guards egg-mass aggressively.

Habitat and Distribution

Cyclopterus lumpus are Benthic organisms that live on rocky bottoms usually between 50 and 150 m, but occasionally to 400 m down on the sea floor, it may occur in floating seaweed. These fishes are basically solitary rather than a schooling fish. Feeding more intensive in the winter. Cyclopterus lumpus is widely distributed in the boreal region of both sides of the North Atlantic. Adults of this species occur in the upper 50 m to 60 m of oceanic waters.