Aphanius Nardo

José L. Blanco, Tomas Hrbek & Ignacio Doadrio, 2006, A new species of the genus Aphanius (Nardo, 1832) (Actinopterygii, Cyprinodontidae) from Algeria., Zootaxa 1158, pp. 39-53 : 40

[[ Aphanius Nardo ]]

The genus Aphanius is currently composed of approximately 16 species, and is distributed along the ancient coast of the Tethys Sea (Kosswig, 1967, Villwock, 1999), which closed at the Oligocene/Miocene boundary (Smith et al, 1995); this area includes both coastal and interior bodies of water in the Mediterranean basin and the Persian Gulf as far as Iran and Pakistan (Kessel & Zee, 1984, Wildekamp, 1993). The greatest species diversity is considered to be in the Near East, especially in Anatolia (Wildekamp et al, 1999), although recent studies suggest that this high diversity should also include Iran (Coad, 2000, Hrbek et al, in press). Diversity is lower in western parts of the range of the genus, where only four species are found: Aphanius apodus (Gervais, 1853) , Aphanius baeticus Doadrio, Carmona and Fernandez-Delgado, 2002 , Aphanius iberus (Valenciennes, 1846) , and Aphanius fasciatus (Valenciennes, 1821) .

Genetically, Aphanius is divided into two major clades (eastern and western) (Hrbek & Meyer, 2003). All four species in the western Mediterranean region are members of the western clade, within which three lineages may be defined. Aphanius apodus was the earliest monotypic lineage to diverge from other members of the western Aphanius clade, whereas Aphanius fasciatus has a relatively nested position within the western Aphanius clade. The next lineage after Aphanius apodus to diverge from remaining western-clade Aphanius is the clade comprising Aphanius iberus , A. baeticus , and the new species described in the present study. Until recently this lineage was considered to be monotypic. However, molecular (Perdices et al, 2001, Hrbek & Meyer, 2003) and morphological (Doadrio et al, 2002) data clearly define two groups showing allopatric distributions, which support the hypothesis that they represent two distinct species, Aphanius iberus and Aphanius baeticus (Doadrio et al, 2002). The species with the broadest distribution, Aphanius iberus , historically occurred in southern France and along the Mediterranean coast of Spain; populations considered to be this species were also known from Morocco and Algeria (Pellegrin, 1921, Kessel & Zee, 1984, Wildekamp, 1993, Doadrio, 1994, Villwock, 1999). Aphanius iberus is currently extant only in remnant populations in Spain. Many North African records are historical and possibly imprecise, since this species does not presently occur in these areas or is known to have become extinct. Other North African literature records are based on second-hand information or lack precise collection or locality data, and thus are highly questionable.

One North African population for which good geographic data exists, the Igli population, has been studied by Villwock & Scholl (1982). Those authors found morphological differences and differences in reproductive biology when compared to Spanish populations of A. iberus and A. baeticus . The absence of new material collected from northern Africa since Dumont’s (1980) and Morgan’s (1981) collections, which are deposited at the Musée Royal de l’Afrique Centrale, Tervuren, Belgium (MRAC), has impeded further studies, including the use of new taxonomic tools such as molecular techniques. Lack of material has not resulted from lack of interest or lack of effort. Rather, adverse political conditions and extensive anthropogenically-induced environmental and faunal changes, with attendant habitat degradation, have impeded collection efforts. However, during an expedition to Algeria in 2004, new material of Aphanius from an oasis system to which Igli is connected (Fig. 2) was collected. This material forms the basis for the current study.