New records of subterranean and spring molluscs (Gastropoda: Hydrobiidae) from Montenegro and Albania with the description of five new species

A short overview of subterranean Balkan hydrobid genera, with special focus on genus Bythiospeum Bourguignat, 1892 and Iglica A.J. Wagner, 1928 is given. In addition, based on recently collected material in Montenegro (Vitoja Spring) and Albania (Krumë), five new species are described, namely: Bracenica vitojaensis n. sp., Islamia montenegrina n. sp., Lanzaia pesici n. sp., Bythiospeum szarowskae n. sp. and Pseudamnicola krumensis n. sp. The holotypes and paratypes are depicted. In addition a re-description of Bythiospeum gittenbergeri (A. & P.L. Reischütz, 2008) is given and the types of the Iglica spp. deposited in the NHMW are depicted, some of them for the first time.


Introduction
Species of the genus Bythiospeum Bourguignat, 1892 live in the interstitial water, they are very minute and even empty shells are only occasionally washed out to the surface. Thus living specimens are very hard to collect. Genus identification of subterranean species is not easy because not all known genera are well defined (Boeters 1998) and equipped with clear distinguishing features. The majority of the known species are narrow range endemics, many of them are known only from the type locality. The recent understanding of the genus Bythiospeum is rather poor and the distinguishing from Paladilhiopsis Pavlovic, 1913 is impossible only by shell morphology, and genital anatomy proves their close relationship too (Szarowska 2006). A molecular phylogenetic reconstruction placed them into the Moitessieriidae as closely related clades, although rejected their monophyly (Szarowska 2006). Already Haase (1995) and Boeters (1998: p. 30) synonymized Paladilhiopsis with Bythiospeum Bourguignat, 1882, but for example the Fauna Europaea check-list (Bank 2013) treat them separately. In this paper we use the name Bythiospeum in Boeters' sense. The shells of representatives of the genus Bosnidilhia look somewhat similar to Bythiospeum, but the shells of Bosnidilhia Boeters, Glöer and Pešić, 2013 are higher in spire, cylindrical, and the body whorl is less prominent. In Bosnidilhia the penis is broad with a small slim and acute penis tip (Boeters et al. 2013: p. 226, figs 3, 4) while the penis in Bythiospeum is more slender and slim over the full length (Boeters 1988: p. 54, fig. 5) or triangular (Glöer & Grego 2015: p. 311, Fig. 20). Radoman (1983: p. 111, fig. 56) depicted a penis similar to Bosnidilhia belonging to Paladilhiopsis grobbeni Kuščer, 1928. Closely related genera as Montenegrospeum Pešić & Glöer, 2013 have an outgrowth on the left side of the penis (Pešić & Glöer 2013a) and it is phylogenetically distinct from Bythiospeum (Falniowski et al. 2014). Balkanospeum Georgiev, 2012 has a red operculum in contrast with the yellowish one in Bythiospeum (Georgiev 2012).
According to Boeters 1998, the representatives of the genus Bythiospeum are distributed from France over Germany and Austria to the Balkans and as far as to the Caucasus Mountains and Uzbekistan. Radoman (1983) who has used Bythiospeum in the strict sense, did not mention any Bythiospeum from the Balkans just two Paladilhiopsis species, namely P. robiciana (Clessin, 1882) and P. grobbeni, from Slovenia. Paladilhiopsis is known from Montenegro (P. serbica (Pavlović, 1913)) in the Durmitor Mts (Páll-Gergely & Erőss 2011) and also from Albania. The latter one was tentatively identified as P. cf. serbica by Fehér & Erőss (2009) but supposed to be a distinct species by Reischütz et al. (2013). Recently five new Bythiospeum spp. were described from Bosnia (Glöer & Grego 2015) and two from Montenegro (Pešić & Glöer 2012). In the eastern Balkans Georgiev & Glöer (2013) listed eight Bythiospeum spp. from Bulgaria and added two new Bythiospeum spp. from western Bulgaria (Georgiev & Glöer 2015). In Bulgaria, Wagner (1928) described Paladilhiopsis bureschi from Temnata Dupka cave, near Lakatnik. Later it was considered as Bythiospeum by Georgiev & Glöer (2013) but its taxonomy of course is still not clear.
In the Balkans species of the genus Iglica are mentioned from Slovenia (Schütt 1975, De Mattia 2007, Croatia, Bosnia, Serbia and Montenegro (Schütt 1975), Albania (Reischütz & Reischütz 2008, Reischütz et al. 2014, Kosovo (Schütt 1975), and Bulgaria (Angelov 1959) but the understanding of this genus is different, some look like Bythiospeum (Figs. 1, 4-5), others like Bosnidilhia (Figs. 2-3) though Wagner (1928: p. 295) compared the shell form with representatives of the genus Acme Hartmann, 1821, this means a cylindrical shell like figs 2-3. Iglica A.J. Wagner, 1928 has not yet been properly redefined and in all likelihood it belongs to Bythiospeum (Boeters et al. 2013). Due to above mentioned arguments we provisionally consider all the shells with slender and cylindrical form as members of Bosnidilhia with possible future reorganizing the species within the Bythiospeum complex (see Georgiev & Glöer 2013) and possible new genera based on soft part morphology and molecular data. With that respect we threat the placement of most of the Balkan representatives in genus Bythiospeum and Bosnidilhia as provisional, until more anatomical and molecular data would allow some deeper revision of these genera and justify its eventual split and allocate by specific criteria to other genera. Pseudamnicola Paulucci, 1878 is known to occur in Croatia (Island Pag, the type locality of P. conovula (Frauenfeld, 1863) and Greece  but not in Albania and Montenegro so far.

Representatives of the genus Plagigeyeria Tomlin, 1930 are distributed from Bosnia and
Hercegovina, Dalmatia, Montenegro, Albania to Bulgaria. Schütt (1972) believed that all Plagigeyeria spp. which occur in Montenegro are subspecies of P. zetaprotogona. Because all these subspecies occur in a small region of the springs of Zeta River, some of them occur syntopically, this subspecies concept of Schütt (1972) proves untenable. The genera Lanzaia Brusina, 1906, Plagigeyeria andSaxurinator Schütt, 1960 are not well defined because their type species have not yet been anatomically examined (Radoman 1983).
This paper contributes to the knowledge of the genera Bythiospeum, Bracenica Radoman, 1973, Islamia Radoman, 1973, Lanzaia andPseudamnicola, andtheir distribution in Montenegro and Albania by description of additional new species.

Material and Methods
The snails were recently collected in Albania and Montenegro by the junior authors with a sieve and by hand and fixed in 75% ethanol. The dissections and measurements of the genital organs and the shells were carried out using a stereo microscope (ZEISS); the photographs were made with a digital camera system (Leica R8).

Systematics I Species from the Vitoja spring in Montenegro
Vitoja Spring is located in Montenegro, by the northeastern shore of the Skadar Lake, near the settlement Hasanoj close to the Albanian border pass Božaj on E762 rd. The lake was long believed to be ancient, but recent studies revealed that it is geologically very young, formed ca. 1200 years ago (Jabłońska et al. 2015). High rate of the lake's inflow comes from over 200 registered temporary and permanent karstic springs, many of them are sublacustrine (Radulović et al. 2015). Vitoja is a large karstic spring zone adjacent to the lake. It consists of one main spring affluent to two joined small spring lakes with several sublacustrine spring zones, and additional five side springs located within 150 m West of the main spring. During high-water, the whole spring system gets under the water level of the lake, and during the summer season, some of the side springs are just occasional or very small. All springs burst at the border between the massive limestone and the alluvium of the Skadar Lake (Fig. 6). The Skadar Lake system is a well-known hotspot of freshwater gastropod biodiversity by its 50 gastropod species (38% endemicity) (Pešić & Göer 2013b). Vitoja Spring hosting eleven species out of which six are endemic to the Skadar Lake Basin.