Petroleuciscus

The genus Petroleuciscus is currently restricted to four species: P. aphipsi, P. borysthenicus, P. ninae, and P. smyrnaeus . These species appear to be closely related, or even congeneric to Ladigesocypris . Both genera are also closely related to Squalius . Petroleuciscus is endemic to the Black, Marmara, and Aegean basins. Other species associated with this genus are now placed in different genera. Petroleuciscus persidis, native to Central Iran, belongs to the genus Acanthobrama . Petroleuciscus kurui and P. ulanus, also native to Iran, belong to Alburnus . Petroleuciscus squaliusculus, native to the Aral Sea basin, belongs to Leuciscus . Finally, P. esfahani, native to Iran, is a synonym of Alburnus doriae .

Further reading. Bogutskaya 1996 (taxonomy); 2002 (systematics); Perea et al. 2010 ( P. persidis); Mohammadian-Kalat et al. 2017 ( P. esfahani); Freyhof et al. 2018a ( P. kurui); Sheraliev & Peng 2021 ( P. squaliusculus); Kalaycı 2022 (Phylogeny); Kaya et al. 2024b ( P. ninae).

Key to species of Petroleuciscus in West Asia

1a - 8–9½ branched dorsal rays; 9–10½ branched anal rays; 7 scales between lateral line and dorsal origin; iris orange to red; posterior margin of anal convex or almost straight; no black pigments along free margin of each flank scale. ...……………… P. borysthenicus

1b - 7–8½ branched dorsal rays; usually 8½ branched anal rays; 6 scales between lateral line and dorsal origin; iris whitish; posterior margin of anal straight or slightly concave; black pigments along free margin of each flank scale. ...……………… 2

2a - Pigments absent or very few orange pigments on anal rays in life; body depth at dorsal origin 24–27 % SL; head width at posterior eye margin 14–16 % SL; eye diameter approximately equal to snout length. ...……………… P. smyrnaeus

2b - Numerous black pigments on anal rays in life; body depth at dorsal origin 27–30 % SL; head width at posterior eye margin 16–19 % SL; eye diameter smaller than snout length. ...……………… P. ninae