Alburnus ulanus

Common name. Mahabad bleak.

Diagnosis. Distinguished from other species of Alburnus in Caspian and Lake Urmia basins by: ● ventral keel between posterior pelvic base and anus absent or very shallow / ○ 12–16 gill rakers / ○ 7–10½ branched anal rays / ○ 33–42+3 lateral line scales / ○ a bold, dark-brown mid-lateral stripe / ○ usually 8½ branched dorsal rays. Size up to 130 mm SL.

Distribution. Iran: Lake Urmia basin.

Habitat. Lowland sections of streams and rivers with slow-flowing to standing water and submerged vegetation.

Biology. Lives for 4 years. Matures at 2 years. Spawns April–June. Feeds on aquatic invertebrates, plants, and phytoplankton.

Remarks. Formerly placed in Petroleuciscus. Alburnus ulanus shares mtDNA with Alburnus atropatenae, but both species are well differentiated by morphological characters, and introgressive hybridisation is probably responsible for the similar mtDNA.

Conservation status. CR; appears to be on the verge of extinction. Several field teams have failed to record it in recent years. Only one individual was found in a heavily polluted stream in 2018. It was once widespread in and around wetlands along lower reaches of tributaries of Lake Urmia. Massive habitat alteration due to construction of many dams has meant that there are now very few slow-flowing lowland rivers and streams left. These, however, have been severely affected by pollution.

Further reading. Abbasi & Sabkara 2004a (food); Abbasi & Sabkara 2004b (biology); Abbasi et al. 2006 (morphology); Ghasemi et al. 2015 (distribution); Coad 2021a (biology, morphology).