Rhodeus caspius, Esmaeili, Sayyadzadeh, Japoshvili, Eagderi, Abbasi & Mousavi-Sabet, 2020

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 85

Rhodeus caspius

Common name. Caspian bitterling.

Diagnosis. Distinguished from R. colchicus by: ● second infraorbital bone narrow / ○ 35−36 total vertebrae / ● 34−37 scales in lateral series. No morphological character known to distinguish from R. amarus . Size up to 60 mm SL, likely to grow larger.

Distribution . Caspian basin from Kura east to Gorgan ( Iran). Introduced to Lake Urmia basin, upper Karkheh in Iran, and possibly elsewhere. Distribution in northern Caspian unknown.

Habitat. Slow-flowing streams and small rivers, backwaters, ponds, and lakes, usually with dense underwater vegetation and sand-silt substrate.

Biology. Spawns April–September. Mating and spawning Behaviour similar to R. amarus . Larvae incubated by Unio bivalves. Feeds on algae, benthic insect larvae, and planktonic crustaceans.

Conservation status. LC.

Remarks. Diagnostic character proposed to distinguish this species from R. amarus could not be confirmed.

Further reading. Bartáková et al. 2019 (phylogeny); Esmaeili et al. 2020a (description).

Figures

Rhodeus caspius

Distribution