Haddock

Look for the black smudge above the pectoral fin - the "devil's thumbprint" of legend - and the dark lateral line, and you have a haddock. Smaller-mouthed and tidier-looking than the cod, it is the signature fish of Britain's northern waters, from Yorkshire wrecks to Scottish lochs and banks.

Haddock shoal over sand, gravel and broken ground, grubbing for brittlestars, worms and shellfish. They are a boat angler's fish for the most part, falling to baited hokkais and small fish baits worked close to the bottom, and where you find one you usually find fifty.

The fight is modest; the eating is the point. Smoked haddock is one of Britain's great foods - Arbroath smokies, Cullen skink, a proper kedgeree - and a box of fresh haddock from a northern bank is worth more than its weight in sport.