Cyprinus carpio

Common name. Common carp.

Diagnosis. Distinguished from other species of Cyprinidae in West Asia by: ○ two pairs of barbels / ○ 15–20½ branched dorsal rays / ○ last unbranched anal ray strongly ossified and serrated at its posterior margin / ○ caudal deeply emarginate. Size up to 1100 mm SL and 50 kg,usually less than 400mm SL.

Distribution. Black, Caspian, and Aral basins. Introduced worldwide, including almost all drainages in West Asia.

Habitat. Warm,deep,slow-flowing,still waters like lowland rivers and large, well-vegetated lakes. Often semi-anadromous in Azov and Caspian basins. Introduced in all types of waters, especially reservoirs. Tolerates permanent salinities up to 8 ‰, temporarily up to 18.6 ‰. Spawns along banks or in backwaters. Successful survival of larvae only in warm water, under shallow submerged vegetation. Eggs hatch in water up to 10 ‰, with good results down to 6.6 ‰.

Biology. Males first spawn at 1−5 years,females at 1−6 years. Usually mature at 1−2 years in warm waters such as southern Iraq. Lives to 50 years and usually spawns annually. Age of maturity varies with latitude and altitude. Spawns late February–late April in Iraq and May−June in northern part of range when temperatures are above 18°C. Reported to spawn again in October−November in southern Iraq. Adults often undertake extensive spawning migrations to suitable backwaters and flooded meadows. Individual female spawn with few males in dense vegetation. Sticky eggs are attached to aquatic plants or other submerged objects. Larvae and juveniles inhabit warm and shallow flooded river margins or backwaters, feeding mainly on very small zooplankton (rotifers). Juveniles and adults feed on various benthic organisms and plant material. Most active at dusk and dawn. Very tolerant of low oxygen levels.

Conservation status. LC in native range. Wild populations have declined sharply since the 18 th century due to river regulation and wetland draining. Cultivated in large quantities for human consumption and stocked for recreational fishing. Wild populations are slowly but steadily declining due to hybridisation with domesticated stocks. Probably very few populations remain “genetically unpolluted” due to this long process. The largest “wild” populations in West Asia appear to exist in lowland wetlands of the southern Caspian basin.

Further reading. Steffens 1958 (biology); Balon 1974, 1995 (domestication); Kottelat 1997 (systematics); Kottelat 2001 a (Asian carps); Chu & Chen 1989 (Asian carps);Baruš et al.2002 (biology); Coad 2010a (biology in Iraq, salinity tolerance).