This dark grey fish is striking in appearance, with huge orange eyes that stare
out into the depths. The roughhead grenadier has, like other grenadiers, an elongate
tail which tapers to a point, and a pointy snout. The rays on its second dorsal
fin are shorter than the anal rays, and both extend along the body to the tail.
The body is covered with thick, tough scales, some of which bear short spines.
These scales not only protect the roughhead grenadier from predators like the
Atlantic cod, but also from commercial fishing – they make it too difficult
to readily process the firm, flaky white flesh. However, when these fishes are
caught in trawls their livers are canned, or rendered into oil.
The roughhead grenadier can grow to be a large fish, reaching a maximum size of
100 cm! They live a long time too, at least 25 years by some accounts, but three
times as long by others. The controversy comes, at least in part, from the difficulty
of determining age based on the ill-defined growth rings in the scales and inner
ear bones. This fish, like some other grenadiers, can produce sound by repeatedly
contracting special muscles against its swim bladder. It is this bizarre behaviour
that led the Inuit to call the fish ingminniset, or "it bellows when
dying." Other English common names for this species include smooth-spined
rattail and onion-eye.
In the west, this fish ranges from the waters off Baffin Island, in the Davis
Strait, south to New Jersey. In the east it is found around Greenland, Iceland,
off Norway, and in the Barents Sea. Its distribution extends to 82 °N, well above
the Arctic Circle! Its preferred habitat is the continental slope at 200-600 m,
but it occurs in waters as deep as 2740 m. It feeds on a wide variety of invertebrates
-crustaceans, worms, comb jellies, sea urchins, molluscs, and the occasional fish.
Spawning occurs in the winter and early spring, when females release up to 71,000
eggs. These eggs are relatively large, measuring about 4 mm in diameter.
