First record of stygobiotic gastropod genus Travunijana Grego & Glöer, 2019 (Mollusca, Hydrobiidae) from Montenegro

Abstract

The stygobiotic genus Travunijana Grego & Glöer, 2019 is one of the typical elements of the subterranean freshwater fauna of the Trebišnjica River Basin in Bosnia and Hercegovina. The previous records of the genus suggested that its distribution was limited to the basin of the Trebišnjica River and adjacent parts of the southwestern Neretva Basin. In this paper we describe a new species, Travunijana djokovicisp. nov. from “Vriješko Vrelo” spring in Montenegro. The recent finding of a new species in the Skadar Lake basin (The Drin River system) suggests the possibility of a subterranean route between the Trebišnjica and the Drin drainages, indicating that likely the endemic subterranean fauna in both basins has a lower level of historical isolation than has been considered so far.

3D X-ray microscopy (Micro-CT) and SEM reveal Zospeum troglobalcanicum Absolon, 1916 and allied species from the Western Balkans (Ellobioidea: Carychiidae)

“…We conclude that the 15 populations investigated in this study encompass mostly single-site or narrow range endemics, subjected to low colonization rates and reduced gene flow between isolated populations. Our results are in sync with studies of other subterranean Western Balkan taxa showing that DNA sequence and morphological diversity reflect the highly differentiated geology and subterranean drainage boundaries associated with the Dinaric karst (Previšić et al 2014;Hlaváč et al 2019;Proćków et al 2019;Grego & Pešic 2021;Ozimec et al 2021) whereby locally isolated island-like landscapes, characteristic of this terrain, provide spatial fragmentation, limited area and low connectivity between subterranean systems (Itescu, 2018). For continental molluscs, the Balkan region is one of the richest reservoirs of endemism in Europe (Cuttelod et al 2011).…”

“…Considering the complex geology of this region, these caves are probably not contiguous such that it is unlikely that the two Zospeum populations share the same subterranean system. It is also plausible that these species inhabit opposite sides of different subterranean drainage boundaries (Grego & Pešic 2021) Dányi's (pers. comm.…”