Scardinius erythrophthalmus (Linnaeus, 1758)

Scardinius erythrophthalmus View in CoL View Figure

Common name. Rudd.

Diagnosis. Distinguished from S. elmaliensis in West Asia by: ● 8−13 gill rakers / ● 9−13½, usually 10−12½, branched anal rays. Size up to 350 mm SL.

Distribution View Figure . In West Asia, in deltaic lakes and lower reaches of Inguri, Rioni, and Çoruh (Georgia), Marmara and Black Sea basins east to Sakarya. Also in lower Yeşilırmak and Kızılırmak ( Türkiye). Absent between Kızılırmak and Coruh, as well as between Sakarya and Kızılırmak. In Caspian basin, lower reaches of Kura and Aras and lakes in Lenkoran region ( Azerbaijan), Anzali and Boojagh wetlands, and Sefid drainage ( Iran). Most European rivers north of Pyrenees and Alps, eastward to Ural and Eya drainages, Aral and White Sea basins; Black Sea basin in Europe. Naturally absent from Iberian Peninsula, Adriatic basin, Italy, Greece south of Pinios drainage, Great Britain north of 54°N, Ireland, and Scandinavia north of 62°N. Introduced in northern Italy, Spain, and Corsica.

Habitat. Nutrient-rich, well-vegetated lowland rivers, backwaters, oxbows, ponds, and lakes. Spawns on roots or submerged vegetation.

Biology. Lives up to 17 years. First spawns at 3–4 years. Fractional spawner. Spawns April–July when water temperature is 12–22°C. Males congregate at spawning sites and drive mature females, often with much splashing, into dense vegetation to spawn. Eggs are very sticky. Feeds mainly on plankton, terrestrial insects, and plant material. Able to adapt to adverse environmental conditions by slow growth and small size at maturity (stunted populations), e.g., in Anzali Lagoon, with a maximum total length of 146 mm, living up to 5 years and spawning at age 1+.

Conservation status. LC.

Further reading. Elanidze 1983 (distribution, biology, Georgia); Kottelat & Freyhof 2007 (distribution, biology); Uğurlu et al. 2008 (distribution in Türkiye); Patimar et al. 2010a (Anzali Lagoon).