Ling: predators of the deep

Ling predators of the deep

The ling is the largest member of the cod family – but, with its elongated body, broad head and wide mouth, it bears a closer resemblance to the conger eel. However, its spineless fins, barbule and tiny scales reveal its relationship to the cod. Its needle-sharp teeth are spread wide in the mouth so that it can secure a good grip on its prey. The body, a mottled green/brown, is covered in slime which gives it a bronze sheen.

Unlike cod, which have three dorsal fins, the ling only has two. The first is short with a dark ‘thumbprint’ at the rear; the second dorsal fin and the anal fin are long and feathery and extend almost to the tail, rather like those of rockling. Both the dorsal and anal fins are edged with white.

Anything will do

An active predator, the ling eats most species of fish, especially pouting, cod, whiting, gurnards and flatfish. It also feeds on crustaceans and starfish on occasion, and if an octopus is unlucky enough to be caught in open water, a ling will make short work of it.

In deep water

Adult ling live mainly in very deep water, though young specimens up to 20 lb (9kg) are found in depths of 20-30m (60-100ft). The larger fish live in water up to 400m (1300ft) deep. They are usually found hiding among reefs and wrecks and have a particular preference for such features as steep-sided rocks and overhangs.


The ling lays up to 60 million eggs in order to ensure the survival of the species (many of the eggs provide a rich food source for other hungry fish). They have particular spawning grounds in the North Sea and Icelandic waters, where the female lays her eggs between March and June in depths up to 200m (650ft). Each egg contains a pale green oil globule which helps it to rise to the surface to float among the plankton.

After ten days the eggs hatch and the small fish grow rapidly. Females grow faster than males and can reach up to 20cm (8in) long in their first year. They stay in fairly shallow coastal waters for two to three years before moving offshore.

Ling are of some commercial importance – they are caught on long lines and in trawling nets. Although a small amount is sold fresh, most of the catch is salted and dried and then exported to Southern Europe.

Where to fish

The Scottish coast, the North Sea and wrecks in the English Channel and Irish Sea are ideal places to go fishing for these voracious monsters. These days large charter boats, using high-tech navigation, can rapidly reach wrecks well away from port – such locations are the closely guarded secrets of the boat skippers. Echo sounders are a great help in the search for large fish.