Haddock, like the cod, belong to the Gadidae family. Visually, it is very similar to the cod, but can be distinguished by the black lateral line running along its white side and distinctive black spot, known as the "devil's thumbprint", above the pectoral fin. A small chin barbel can be found on their lower jaw and the dorsal fin is split three ways.
The haddock is very sensitive to temperature which makes it a very active traveller, changing location depending upon the water conditions.
It lives in shoals and is a very peaceable fish, preferring to inhabit waters that are further away from the coasts.
The haddock reaches a maximum length of about 110 centimetres. On the market it averages at a length of 50 centimetres and weighs about two kilograms. The oldest fish of this type live to be 20 years old.
They reach sexual maturity between the third and eighth year and, from January to July, the female haddock lays up to a million eggs. Afterwards, sea currents often transport young larvae great distances from their hatchery.
Haddock prefer to feed on worms, crabs and mussels, but may also feed on young fish.
