Cyclopterus

[6] Cyclopterus and C. lumpus were both first formally described in 1758 by Carl Linnaeus in the 10th edition of the Systema Naturae with the North and Baltic Seas given as its type localities.

This seems to refer to the dorsal fin being embedded in the thick and tubercular skin on the back, creating the impression of a hump.

[14] As they grow they migrate out into open water far from land where they live in the pelagic zone[15] feeding upon gelatinous zooplankton, fish eggs and small crustaceans.

[17] The female will lay the eggs in a nest area pre-selected by the male, which will usually consist of a rocky outcrop or boulders on the seabed.

[21] Several aspects of their biology (i.e. lack of a swimbladder, its pelvic suction disc) led some to believe that they were a bottom dwelling species.

[22] Lumpfish are frequently caught in pelagic fishing nets,[15][23] however, capture in bottom trawls is also common.

[26] As the fish came close to breeding, they began to spend a greater amount of time in the pelagic zone.

[24][26] The current understanding is that after the juveniles leave coastal areas, they adopt a pelgic lifestyle, inhabiting the upper 50–60 m of the water column.

Juvenile lumpfish exhibit biofluorescence,[27] that is, when they are illuminated, light absorbed by the organism is remitted in lower energy wavelengths.

In recent years, Iceland and Greenland have been the two largest fishing nations in regards to lumpfish and account for >95% of the global catch.

[29] Female fish are the main target for the fishery which utilizes the roe to make lumpfish caviar.

[29] Lumpfish are targeted close to the shore, where they come to spawn, using small fishing boats (generally less than 15 m or 49 ft) with large mesh gillnets.

Cyclopterus roe, a good source of omega-3 fatty acids, is used to produce relatively inexpensive caviar substitutes.

The female lumpfish is rarely eaten fresh but when it is caught during the spawning season, the guts and head removed, scored deeply with a knife and hung in a cool place until the flesh turns yellow.

They are used as "cleaner fish" to reduce the parasite burden on salmon farms in Scotland, Iceland and Norway.

Female lumpfish close to spawning. The large orange ovary can be seen.
Total worldwide landings of lumpfish roe.
Biomass index of lumpfish around Iceland and in the Barents Sea (Norway) during 1985-2018. Data from the Marine and Freshwater Research Institute (Iceland) and Institute of Marine Research (Norway).
The caviar of the lumpfish