Members of the cod family are abundant in the seas of Northern Europe. Although haddock and cod are more important commercially because of their larger size, whiting are perhaps the most plentiful of them all.
Whiting are slender-bodied fish with narrow, pointed heads. The upper jaw overhangs the lower and, in addition to smaller teeth, the mouth is filled with a staggered row of large, outward-pointing teeth, useful for hanging on to wriggling prey.
Like other members of the cod family, whiting have three dorsal and two anal fins, which are all joined together at the base. You can distinguish whiting by the white edging on the anal fins, and by the black spot at the upper edge of the pectoral fin. Whiting do not have a chin barbel, although a minute one can occasionally be spotted on young fish.
Their colouring is subtle and varies with habitat. On sandy shores whiting have pale brown backs and elsewhere they may be greeny-blue, but they always have light silver sides and belly – hence the name whiting.
Whiting are common in most shallow inshore waters – young fish can be caught in a few feet of water, but larger specimens live at depths of 30-100m (100-330ft). They tend not to be found in estuaries since they prefer very salty water.
The North Sea and the Irish Sea, and both the Bristol and the English Channels are the main commercial fishing grounds. In the North Sea, however, trawlers are not permitted to bag any fish below 23cm (9in) in a bid to counteract over-exploitation.
Whiting appear to be most active at dawn and dusk – they eat large quantities of small fish such as young herring, sprats and various members of the cod family. Sandeels are important in their diet though the present scarcity of sandeels is probably one reason for the whiting’s decrease. Young fish feed heavily on crustaceans, particularly sandhoppers and brown shrimps.
Spawning begins in mid January off Spain and continues to late May off Iceland, so those around Britain and Ireland spawn in March/April. They spawn offshore in mid-water when the temperature is 10-15°C (50-59°F). Once the eggs have hatched the young live out at sea for up to a year before drifting inshore.
Young whiting are often seen in the company of large common jellyfish which float near the surface. They dart between the jellyfish’s tentacles, and don’t seem to be affected by the venom-filled stings. In this way, whiting gain protection from predatory fish and birds. They may also pick up food from the jellyfish which have small crustaceans living on them. No-one is sure how, or if, the jellyfish benefits from this association. Whatever the advantages, little is known about this unusual behaviour in one of our most common sea fish.