Distribution of natural populations of the killifishAphanius fasciatus(Valenciennes, 1821) (Teleostei: Cyprinodontidae) in Italy: past and current status, and future trends

Abstract

The census of natural populations provides relevant information for both conservation purposes and environmental monitoring. In the present work, natural populations of the killifish Aphanius fasciatus (Teleostei: Cyprinodontidae) were censused in the Italian territory. The historical distribution of the species was reconstructed with the aid of bibliographic material and museal samples, in order to evaluate the extent of changes in its distribution. Three periods (pre-1990s, 1990s, post-1990s) and five habitat types (lagoons/coastal ponds, saltworks, canals, river mouths, inland water bodies) were considered. Overall, we recorded the presence of A. fasciatus in 82 localities, the majority of which are lagoons/ponds. The species showed a widespread decline and sometimes local population extinction, due to habitat degradation and competition with the introduced poeciliid Gambusia holbrooki. With a few exceptions, A. fasciatus is currently extinct in inland waters, being mainly present in coastal brackish-water habitats. The occurrence of stable populations along the central Tyrrhenian, northern Adriatic, Sardinian and Apulian coastal biotopes is confirmed. The populations of Sicilian inland waters, considered extinct, showed recovery capabilities. In northern Tuscany, where the species was also considered extinct, there are also recent records. From a temporal perspective, the present work shows that A. fasciatus experienced population reductions throughout its range in the 1990s, when the species appeared locally extinct, or strongly rarefied, in several localities. Since then, the species recovered in the majority of the native range. However, careful monitoring is needed in order to control the effects of habitat alterations and competition with G. holbrooki on natural populations of A. fasciatus. Given the importance of brackish-water habitats as both biodiversity hotspots and buffer areas against rainfalls and floods, A. fasciatus may be raised to the status of "umbrella species" with regard to these habitats.

First record of Aphanius almiriensis from Italy and notes on the distribution of Aphanius fasciatus (Teleostei: Aphaniidae)

“…The conservation status of A. fasciatus as LC is confirmed by our research. We are aware 153 populations of this species (Figure , Table ) which was found to have recently a positive population trend in Italy (Valdesalici et al, ).…”

“…Killifish of the genus Aphanius are small fishes inhabiting fresh to hypersaline waters around the Mediterranean, the Red Sea, the Persian Gulf and the coasts of the Indian Ocean eastwards to India and southwards to Somalia. From Italy, only one species is known, A. fasciatus , which is widespread along the coasts, mostly inhabiting estuaries and coastal lagoons (Valdesalici, Langeneck, Barbieri, Castelli, & Maltagliati, ). Aphanius fasciatus is also known from Syria and Israel in the east to southern France (extirpated) and eastern Morocco in the west (Kottelat & Freyhof, ).…”

Lagoon Resident Fish Species of Conservation Interest According to the Habitat Directive (92/43/CEE): A Review on Their Potential Use as Ecological Indicator Species

“…fasciatus is one of the most eurythermal and euryhaline species of the Mediterranean Sea, being able to withstand temperature changes between 4 and 40 • C and to reproduce at a salinity between 10 and 80 [20]. Despite this high capacity to adapt to extreme physical-chemical conditions, the genetic variation within-population is very small and is threatened by natural and anthropogenic pressures [25,32]; coupling this with the scarce gene flow among populations [24], the species survival can be locally compromised [33]. This situation was reported in the Maltese island, where only four populations were found in hydrologically isolated sites [34].…”

“…It is widely distributed along the coasts of central Mediterranean basin; in the easternmost coasts it is scarcely abundant because A. dispar is present, even if, in some Egyptian lagoons, both species have been reported and hybrids have been observed [33]. In the westernmost areas, only A. iberus has always been recorded.…”

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“…For several years, the only information on Iranian Aphanius was concerning their distribution, general morphology and few biological aspects (Coad & Abdoli, 2000;Coad, 2009;Esmaeili & Shiva, 2006). The recent extensive studies however improved our knowledge about different aspects of the genus Aphanius such as; their distribution (Caod, 2009;Keivany & Ghorbani, 2012;Teimori, Esmaeili, Gholami, Zarei, & Reichenbacher, 2012a;Esmaeili et al, 2014;Valdesalici, Langeneck, Barbieri, Castelli, & Maltagliati, 2015;Englezou, Gücel, & Zogaris, 2018), taxonomy (Teimori, Schulz-Mirbach, Esmaeili, & Reichenbacher, 2012b;Teimori et al, 2018), phylogenetic relationships (Hrbek, Keivany, & Coad, 2006;Esmaeili et al, 2014;Gholami, Esmaeili, Erpenbeck, & Reichenbacher, 2014;Freyhof, Weissenbacher, & Geiger, 2018;Teimori et al, ,2018 and biological properties (Esmaeili & Shiva, 2006;Bibak, Hosseini, Koohani, & Daliri, 2012;Zeinali & Motamedi, 2017;Teimori, 2018).…”