Barbel (Barbus barbus)
Current record: 21lb 2oz
Water: River Rother, Fittleworth, Sussex
The barbel (Barbus barbus) is a freshwater fish found in rivers across much of Europe and western Asia. Its most recognisable feature is a set of four barbels around the mouth, sensory whiskers it uses to feel out food on the riverbed when visibility is poor.
Unlike many coarse species, barbel favour faster-flowing water over clean gravel or rocky beds, where oxygen levels stay high. They're built for it: a streamlined, muscular body in shades of olive-brown or bronze, built to hold position against a strong current.
Barbel can grow large, with fish over 20lb caught in UK rivers, and they're known among anglers as one of the hardest-fighting species around, a hooked barbel will use the current against you every chance it gets.
They feed mostly at night, rooting through gravel with that underslung mouth for insect larvae, crustaceans, and molluscs, though they'll take small fish and plant matter too. Diet shifts with age, young fish rely heavily on diatoms and midge larvae before moving on to a broader diet as adults.
They're also surprisingly mobile for a bottom-dweller. Tagging studies have tracked barbel moving tens of metres a day and covering many kilometres over a year, work that's shed light on how far a population can range within a single river system.
Habitat loss and pollution remain the main threats, particularly to the clean, well-oxygenated gravel runs barbel depend on for spawning.