Rutilus rutilus (Linnaeus, 1758)

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 395-396

Rutilus rutilus

Common name. Roach.

Diagnosis. Distinguished from other species of Rutilus in West Asia by: ○ 39–42+2–3 (41–44 total) lateral-line scales / ○ body laterally compressed / ○ abdomen posterior to pelvic base compressed / ○ usually 10½ branched dorsal rays / ○ usually 10½ branched anal rays / ○ iris from yellowish in juveniles to deep red in adults / ○ pectoral, pelvic and anal orange to red / ○ no midlateral stripe / ○ lateral line complete / ○ 7–9 scales between dorsal origin and lateral line. Size up to 500 mm SL.

Rutilus rutilus ; Lake Apolyont, Türkiye; ~ 100 mm SL.

northern Caspian basins, as there appears to be some introgressive hybridisation between R. rutilus and R. lacustris , and many hybrid populations occur in that region.

Further reading. Berg 1949b (biology, systematics); Holčík & Skorepa 1971 (biology); Kottelat 1997 (systematics); Kottelat & Freyhof 2007 (distribution, biology as R. heckeli & R. caspicus ); Larmuseau et al. 2009 (distribution); Geiger et al. 2014 (molecular data); Artaev et al. 2021 (distribution, hybrids with R. rutilus ).

Distribution. In West Asia, restricted to Black Sea basin, confirmed from Lake Sapanca, Sursuluk, and Sakarya. Introduced to Cyprus. Europe north of Pyrenees and Alps, east to Volga. In Azov, Black and Caspian basins probably restricted to upper and middle reaches of rivers, replaced by R. lacustris and hybrids between both in lower reaches. Present in Lake Vegoritis in Greece. Naturally absent from Iberian Peninsula, western France, Adriatic Basin, Italy, UK north of 56°N, Scandinavia north of 69°N. Locally introduced and invasive in northern Italy, Spain, and Portugal. Introduced in North Africa.

Habitat. Mostly in lowland areas and in lakes. Common in nutrient-rich lakes and large to medium-sized rivers and backwaters. Takes advantage of channeling, damming, and light organic pollution. Small lowland streams, brackish coastal lagoons, and fast-flowing rivers where it is restricted to sections where backwaters or shelters allow overwintering. Spawns in dense submerged vegetation in backwaters or lakes, flooded meadows, or shallow, fast-flowing river habitats on vegetated or gravel bottoms.

Biology. Lives up to 13 years. Males first spawn at 2–3 years, females 1 year later, usually at about 100 mm SL. Undertakes short spawning migrations, sometimes beginning as early as September, generally peaking at temperatures above 9°C in spring. Spawns in April–May when temperatures rise above 12°C. Usually, an entire population spawns within 5–10 days. Spawns in shoals. Eggs are sticky and hatch in about 12 days. Larvae and juveniles occupy a wide range of littoral habitats. Feeds mainly on benthic invertebrates, zooplankton, plant material, and detritus. Populations feeding predominantly on detritus are often stunted (stunted populations may also be associated with strong year classes). May shift from littoral to pelagic habitats and between benthic and zooplankton when a particular food is abundant or to avoid predation and/or competition. Decision to remain in open water or among littoral vegetation is often described as a trade-off between food intake and predator avoidance. During growth, there is an energetic need to switch from zooplankton to benthic food (chironomids, molluscs). Individuals able to feed on

Dreissena mussels increase their growth rate but do not exploit this food source until they reach about 120 mm SL (size at which they can crush mussels). In some areas (Volga reservoirs), pelagic and benthic roach can be distinguished by life history characteristics (spawning time, spawning sites), and these may represent sympatric populations of R. rutilus and R. lacustris . Overwinters in backwaters or deep parts of lakes. Often produces fertile hybrids with Abramis brama .

Conservation status. LC.

Further reading. Holčík & Skorepa 1971 (morphology); Kottelat 1997 (systematics); Larmuseau et al. 2009 (distribution); Kottelat & Freyhof 2007 (distribution, biology); Zogaris et al. 2012 ( Cyprus); Artaev et al. 2021 (distribution, hybrids with R. lacustris ).

Rutilus sojuchbulagi ; spring in Akstafa region, Azerbaijan; ~ 70 mm SL (modified from Abdurakhmanov 1950).