Haddock, a well-known fish of the cod family. It is smaller than the cod, which it much resembles, and it has a dark line along its side and a dark spot just behind the head. This fish commonly weighs from two to six pounds, though sometimes it weighs as high as ten pounds. It breeds in immense numbers in the northern seas in February and March and constitutes a considerable article of food. It is plentiful on the coasts of America, from New York to the Arctic regions. While not as valuable as the cod, the haddock is an important food fish. When dry-salted it is placed on the market as finnan haddie.