Tusk: the deep-water predator off Norway with just one dorsal fin

October 24, 2026

A cod relative with just one dorsal fin, a barbel on its chin and a home far down: in the northeast Atlantic, according to FishBase, it mostly lives at depths of 150 to 450 metres. This article is about the tusk, *Brosme brosme* — in North America cusk, German Lumb, Norwegian and Danish brosme, Swedish lubb, Finnish and Icelandic keila, Dutch lom, French brosme, Spanish and Italian brosmio, Portuguese bolota, Russian менёк (GBIF), Greek βρόσμιος, Japanese アツカワダラ and Arabic برسم (Wikidata). For Turkish, Croatian, Slovenian and Albanian we found no confirmed species name of their own in Wikidata and GBIF. It is a predator of the cold, rocky deep ground off Norway, Iceland and the Faroe Islands — and anyone fishing from a boat over deep rock there may well get one on the hook. Here is how to recognise it, where it lives, what it eats, when it spawns — and why a fish that needs eight to ten years to reach sexual maturity is under quota.

A burbot relative from the deep

According to the German Wikipedia, the tusk belongs to the burbot family (Lotidae) — like the ling in the sea and the burbot in fresh water — and is the only member of its genus *Brosme*. According to GBIF and the German Wikipedia, it was described by Peder Ascanius in 1772. According to the English Wikipedia, it is a sluggish bottom fish and a weak swimmer; the German Wikipedia describes a limited range of movement and knows of no documented larger migrations. According to FishBase, it lives alone or in small groups, mostly far offshore near the bottom.

How to recognise it

According to the German Wikipedia, its body is spindle-shaped with a large head; on the lower jaw sits a single barbel, and the upper jaw protrudes slightly. The dorsal and anal fins are strikingly long, reach the tail fin and are partly joined to it — according to the English Wikipedia joined at the base but separated by deep notches; the tail fin is evenly rounded. The pelvic fins sit on the throat and are fleshy. According to the German Wikipedia, the colour ranges from brown to grey with a paler belly, according to the Norwegian Wikipedia also yellowish brown; the unpaired fins have a black margin with a white edge. According to the German Wikipedia, juveniles show six yellow vertical bands. The tiny scales are deeply embedded in a thick, slimy skin.

Size: typically 60 to 95 cm in the eastern and 50 to 80 cm in the western Atlantic according to the German Wikipedia, about 70 cm and 3 kg according to the Norwegian Wikipedia; FishBase gives 50 cm as the common length. Record fish — see the contradictions below.
Age: up to 20 years according to FishBase and the German Wikipedia, probably over 20 years according to Norway’s Institute of Marine Research (Havforskningsinstituttet, HI).
Most common mix-up: the ling (*Molva molva*) and the cod — both have more than one dorsal fin. According to the English Wikipedia, the single dorsal fin is exactly the feature that sets the tusk apart from other cod-like fishes.
Juveniles: have six yellow vertical bands according to the German Wikipedia, broad yellow vertical bands according to the Norwegian Wikipedia, and often yellow bands according to the English Wikipedia. If you bring up a small banded fish from the deep, look for the one long dorsal fin.

What it eats: crustaceans, molluscs — and fish

According to the German Wikipedia, its diet consists mostly of crustaceans and molluscs; it also takes bottom-dwelling fish. FishBase lists crustaceans, bivalves and snails, bottom fish and even starfish, and gives it a trophic level of 3.9. The Norwegian Wikipedia names crustaceans and bristle worms, whereas the HI puts fish first, plus larger crustaceans such as shrimps. According to FishBase, it is itself on the menu of seals.

Where it lives: deep, cold and rocky

In the northeast Atlantic, according to the German Wikipedia and FishBase, its range extends from Iceland via the northern North Sea and the Scandinavian coasts to the Barents Sea near Murmansk and to Svalbard; the HI also names the Skagerrak and Kattegat as well as Ireland. In the western Atlantic it lives from New Jersey to the Grand Banks of Newfoundland. According to the Norwegian Wikipedia, it is common along the entire Norwegian coast, in deep fjords and on the continental slope.

It needs hard ground: according to the German Wikipedia rock, rubble, gravel and steep slopes; it mostly avoids smooth sandy bottoms and stays away from the coast and shallow water. According to FishBase and the German Wikipedia, the water temperature lies between 0 and 10 °C. Its depth: 18 to 1,000 metres according to FishBase, mostly 150 to 450 metres in the northeast Atlantic; according to the English Wikipedia usually deeper than 180 metres and rarely in harbours. According to the HI, juveniles are found considerably shallower. Stocks at Rockall and on the Mid-Atlantic Ridge are genetically distinct according to the HI and the English Wikipedia — depth and currents separate them.

Slow to grow: spawning, eggs, maturity

According to the German Wikipedia, spawning takes place at 100 to 200 metres, according to FishBase at 40 to 400 metres, mostly 100 to 200. According to the Norwegian Wikipedia, the main spawning grounds lie between Scotland, the Faroe Islands and Iceland; the HI also names areas off southern and central Norway. According to the German and English Wikipedias, a medium-sized female releases up to two million eggs. The eggs drift, measure 1.3 to 1.5 mm according to the German Wikipedia and develop slowly near the surface; the young fish live in open water until about 5 cm and then move to the bottom. And it grows slowly: according to the German Wikipedia it only reaches sexual maturity at eight to ten years and 40 to 50 cm. FishBase gives the generation time as 8.1 years.

Fishery, quota and status

According to the German Wikipedia, the tusk was fished increasingly from the 1990s onwards; unregulated exploitation endangered the stocks, and since 2003 the EU has regulated it through total allowable catches and quotas. According to the HI, Norway takes around 70% of the total catch, 13,800 tonnes in 2023; landings in the North Atlantic fell from almost 30,000 tonnes (2010) to 19,000 tonnes (2023). For 2026 and 2027, according to the HI, ICES advises 5,336 tonnes per year for the stock in ICES areas 4, 7–9, 3.a, 5.b, 6.a and 12.b, after 8,071 tonnes for 2024 and 2025. According to the HI, it is also taken as bycatch in trawls, gillnets and longlines. In Canada, according to the English Wikipedia, it has been considered endangered since an assessment in 2012; catches in a summer survey there fell by around 90% between 1970 and the late 1990s.

According to the German Wikipedia, its flesh is firm and white and tastes slightly of lobster; in Scandinavia it is also made into stockfish. According to the English Wikipedia, however, it accumulates methylmercury, with higher levels in fjords than on the coast and in the open sea. For you on the water, that means: check the rules of the fishing area before the trip — quotas, minimum sizes, export rules for visitors —, ask the skipper on a guided boat, and with fjord fish follow the local consumption advice. And because it comes from great depth: we found no reliable data on how well a tusk survives release after being brought up from 200 metres. So plan to keep only what you will use instead of relying on release.

Five contradictions in the sources

How big does it get? German Wikipedia: up to 110 cm. FishBase: 120 cm and 30 kg as the published maximum weight. English Wikipedia: around 120 cm and 20 kg. Norwegian Wikipedia: about 130 cm and 20 kg. HI: about 1.1 m and 15 kg. According to the English Wikipedia, the IGFA world record stands at 17.2 kg, caught off Sørøya in northern Norway.
When does it spawn? English Wikipedia: April to early July. Norwegian Wikipedia: April to August. HI: April to August in the text, April to June in the fact box on the same page.
When does it mature? German Wikipedia and HI: at eight to ten years. Norwegian Wikipedia: at six to ten years. The German Wikipedia gives 40 to 50 cm for this, FishBase a mean length at maturity of 53.3 cm.
How threatened is it? English Wikipedia: Least Concern on the IUCN Red List. FishBase: Not Evaluated (version 2025-2). The EU database EUNIS: not threatened in Europe, not evaluated globally. Canada: endangered.
Who described it? GBIF and German Wikipedia: Ascanius 1772. Norwegian Wikipedia: Linnaeus 1758.

Three traps in the name

In German, Lumb is not Lump. GBIF lists “Lump” as a German alternative name for the tusk (German: Lumb) — but in German the lumpfish (*Cyclopterus lumpus*) is also called Lump or Lumpfisch, a completely different fish with a sucker disc. If you read “Lump” in a German source, check the scientific name.
“Torsk” is the tusk in English, but the cod in Scandinavia. GBIF and Wikidata list torsk as an English name of *Brosme brosme*; in Norwegian, Swedish and Danish, however, torsk means the cod.
Brosme is not brasme. The Norwegian Wikipedia expressly warns against confusing it with the brasme — the freshwater fish known in English as the common bream (*Abramis brama*).

That leaves the question every article in this series starts with: when. Habitat, prey and habits are above, and they are fixed. What changes every day is everything else — light, air pressure, wind, current, water temperature — and whether a day on the water is worth it is decided right there. That is what StrikeAhead calculates: it takes the conditions on your water and tells you when the trip is worth it. And because you don’t know unfamiliar deep ground, its edges and its rules from day one, StrikeAhead Pathfinder tells you who to head out with: curated guides and skippers, personally vetted before listing — licence and insurance —, with verified catches instead of advertising photos, no paid ranking and no booking fee for you as an angler. The app tells you when, Pathfinder tells you with whom.