Esmaeilius shirini

Common name. Shirin killifish.

Diagnosis. Distinguished from other species of Esmaeilius by: ● male usually with 7–11 wide, brown bars on flank / ○ male with wide and white dorsal margin / ○ female with irregular set brown or dark-grey spots and blotches / ○ female without or with a very small black spot at caudal base / ○ 25–31 total scales along lateral series. Size up to 36 mm SL.

Distribution. Iran: Khosroshirin, a headwater spring-stream system in upper Kor drainage and Arjan wetland in Helleh drainage (introduced).

Habitat. Streams and springs with low to moderate current, gravel and mud substrate covered with dense filamentous algae.

Biology. No data. Expected to be similar to other Esmaeilius.

Conservation status. CR; has declined sharply in its last native habitat and may be on the verge of extinction, occurring in only one non-native habitat.

Further reading. Gholami et al. 2014 (description, biogeography); Esmaeili et al. 2020b (molecular data and distribution); Freyhof & Yoğurtçuoğlu 2020 (generic position).