The lumpfish has a stout body. Its dorsal fin thickens with age, eventually becoming a thick ridge. It has no scales. Instead, its body is covered with bony tubercles.
Lumpfish can grow to a maximum of 70 cm. Their pelvic fins have evolved into suckers so that they can attach themselves to rocks.
They usually live between 50 and 300 m underwater, but come to the surface and toward the shore during their mating period. At that time, their colouring becomes brighter.
The male is then orange-red and the female, often bigger than the male, is blue-green in colour. She can carry 1,000 to 2,000 ‘eggs’.
She nears the coastline between May and July to deposit her eggs in a spongy mass glued to the rocks. The male fertilizes the clutch and protects it for 6 or 7 weeks, until it hatches. The female returns to the deep immediately after laying her eggs.
Lumpfish feed mainly on crustaceans but also on worms, molluscs and echinoderms (sea urchins and sea stars).
The gelatinous flesh of the lumpfish has no commercial value in France. It is mainly caught for its eggs, which can be used as a substitute for caviare after salting them in brine.
