Barbus barbus

The common barbel, Barbus barbus, is a species of freshwater fish belonging to the family Cyprinidae. It shares the common name 'barbel' with its many relatives in the genus Barbus, of which it is the type species. In Great Britain it is usually referred to simply as the barbel; similar names are used elsewhere in Europe, such as barbeau in France and flodbarb in Sweden. The name derives from the four whiskerlike structures located at the corners of the fish's mouth, which it uses to locate food. B. barbus is native throughout northern and eastern Europe, ranging north and east from the Pyrénées and Alps to Lithuania, Russia and the northern Black Sea basin. It is an adaptable fish which transplants well between waterways, and has become established as an introduced species in several countries including Scotland, Morocco and Italy. Although barbel are native to eastern flowing rivers in England, they have historically been translocated to western flowing rivers, such as the River Severn. Its favoured habitats are the so-called barbel zones in fast-flowing rivers with gravel or stone bottoms, although it regularly occurs in slower rivers and has been successfully stocked in stillwaters. Barbel are very abundant in some rivers, often seen in large shoals on rivers such as the Wye. Izaak Walton reported that there were once so many barbel in the Danube that they could be caught by hand, 'eight or ten load at a time' . Adult B. barbus specimens can reach 1.2 m (4 ft) in length and 12 kg (26 lb) in weight, although it is typically found at smaller sizes (50–100 cm length, weight 1–3 kg). Adult barbel can live to over 20 years of age. Their sloping foreheads, flattened undersides, slender bodies and horizontally oriented pectoral fins are all adaptations for their life in swift, deep rivers, helping to keep them close to the riverbed in very strong flows. Juvenile fish are usually grey and mottled in appearance; adults are typically dark brown, bronze or grey in colour with a pale underside, with distinctively reddish or orange-tinged fins. The lobes of the tail are asymmetrical, the lower lobe being rounded and slightly shorter than the pointed upper lobe. Barbel commonly feed at night, although they may feed during the daytime in the safety of deeper water or near underwater obstructions. Their underslung mouths make them especially well adapted for feeding on benthic organisms, including crustaceans, insect larvae and mollusks, which they root out from the gravel and stones of the riverbed. Barbel diets change as the fish develop from young of the year to juveniles and then to adults. As young of the year the diatoms that cover rocks and the larvae of non-biting midges (Chironomids) are particularly important foods. Males become mature after three to four years, females after five to eight years. Spawning occurs between May and late June on most rivers, when groups of males assemble in shallow water in pursuit of mates. Upstream migration to reach spawning grounds can happen between March and May, but will depend on the temperature. Like many fish species, male barbel develop distinctive tubercles on their heads prior to spawning. Females produce between 8,000 and 12,000 eggs per kilogram of bodyweight, which are fertilised by males as they are released and deposited in shallow excavations in the gravel of the riverbed. Individual barbel can move between 16 and 68 km in a year, with mean (average) daily movement between 26 and 139m. Parasites of Barbus barbus include Aspidogaster limacoides, a trematode flatworm;, Eustrongylides sp. a nematode and Pomphorhynchus laevis, an acanthocephalan worm. Many authors have noted the highly toxic nature of barbel roe when eaten by humans, including Dame Juliana Berners and Charles David Badham. Badham relates the experience of Italian physician Antonio Gazius, who, he says, 'took two boluses, and thus describes his sensations: 'At first I felt no inconvenience, but some hours having elapsed, I began to be disagreeably affected, and as my stomach swelled, and could not be brought down again by anise or carminatives, I was soon in a state of great depression and distress.' His countenance was pallid, like a man in a swoon, deadly coldness ensued, violent cholera and vomiting came after until the roe was passed, and then he became all right.'