Barbel are slim and streamlined – a sure sign that they are mainly river fish. Their colours are typical of the carp family they belong to, with green or brown backs, golden-bronze flanks and pale bellies, though in clear water they can be a much darker brown-black.
Feeling for food
These fish are well adapted for bottom feeding in fast-flowing rivers. Their long, pointed heads with underslung mouths are ideal for digging around in the gravel over which they prefer to live. Their barbels -the distinctive feelers after which they are named – are extremely sensitive to touch and taste and so are very useful in scouring the bottom in search of insect larvae and other tasty morsels.
Favourite foods are worms and insect larvae, crustaceans such as crayfish and shrimps, and molluscs including snails and freshwater mussels. Barbel also eat small fish, especially those living on the bottom of the river, such as loach and bullheads. Hard foods present no difficulty as barbel, like all members of the carp family, have powerful crushing teeth in their throats.
In winter, when the water is colder, barbel feed with less enthusiasm. But in the floodwater conditions common in winter and early spring, barbel can become highly active, feasting on the prey animals washed into the river.
Although Stillwater populations of barbel exist, they are far more common in rivers, especially where the flow is fast enough to prevent silt being deposited. This means they are usually found over a clean gravel bottom where they like to spawn and feed. They also prefer water with a high oxygen content so you can often find them in the outfalls of weirs.
Barbel spawn between May and July, when they make their way upstream in large shoals to gravel beds in shallow water. Once there, the female makes a redd (a depression in the gravel for the spawn), where the sticky eggs are fertilized. After-spawning, the exhausted fish rest up in still water under the banks until they have regained their strength.
Young barbel appear dappled and are covered with numerous dark spots and blotches. It is easy to mistake one of these for a large gudgeon, though gudgeon have only two barbels. They reach maturity after about four to five years, when they are anything from 25-75cm (10-30in) long. A 50cm (20in) barbel weighs about 5 lb (2.3kg).
In common with many other coarse fish, specimens from the Continent are usually bigger and can reach 20 lb (9kg). The warmer weather provides longer periods of rich feeding in the summer.