Potential rediscovery of the endemic critically endangered Sahara killifish (Apricaphanius saourensis) in Algeria

Abstract Apricaphanius saourensis was described in 2006 from the Saoura River in western Algeria, the only known aphaniid in that region. Since then it has not been found in field surveys within the known geographic range, and the hypothesis that the species is possibly extinct in the wild has been raised. It has been recommended that further field surveys in the area should be conducted to clarify the conservation status of the species. Here we report the discovery of a significant aphaniid fish population in a very isolated wadi, approximately 115 km northwest of A . saourensis’ type locality, which might belong to A . saourensis based on images taken of live individuals. Given the critically endangered status of A . saourensis , rather than handling or sampling individuals for analyses, we decided to start by obtaining images of living specimens from the population we discovered to compare the phenotypes with those described as diagnostic for the species. However, morphological and genetic analyses will be necessary to ascertain whether the population indeed belongs to A . saourensis or to a new species that has not yet been described.