Re-validation and re-description of an endemic and threatened species, Aphanius pluristriatus (Jenkins, 1910) (Teleostei, Cyprinodontidae), from southern Iran

Aphanius pluristriatus (Jenkins, 1910) (Cyprinodontidae) is a poorly known species from Fasa, located in the Mond River drainage system, east of Shiraz, southern Iran. It has not been investigated since its first description, its validity has been questioned and a synonymy with A. sophiae (Heckel, 1849) has been suggested. In this study, we describe a new collection of Aphanius specimens from the Zarjan spring system, which is probably the same spring system from where Jenkins (1910) collected the type specimens of A. pluristriatus. The morphological characters of our new series of specimens are consistent with those of A. pluristriatus as originally described by Jenkins (1910). We emend the original description of A. pluristriatus and add morphometric and meristic data. A comparison with the related taxa A. sophiae, A. farsicus (former A. persicus) and A. isfahanensis reveals that A. pluristriatus can be separated from them by a smaller caudal peduncle index, higher number of flank bars, lower number of gill rakers, and higher J scale index. Therefore A. pluristriatus represents a valid species, which is at present restricted to the drainage system of the Mond River. We suggest that A. pluristriatus originated from an ancient A. sophiae population in the Kor River Basin during the Quaternary. At that time, the Kor River was draining to the Persian Gulf by the “Paleo-Kor River” and the Mond River. During the Late Quaternary or Holocene, the connection between the Kor River and the Persian Gulf has been blocked as a result of tectonic uplift (the Kor River Basin is endorheic today). Thus, A. pluristriatus most likely is the relict of an ancient Aphanius population from the Quaternary “Paleo-Kor River” drainage system.