Bythiospeum demattiai, Glöer & Pešić, 2014

Glöer, Peter & Pešić, Vladimir, 2014, New subterranean freshwater gastropods of Montenegro (Mollusca: Gastropoda: Hydrobiidae), with description of one new genus and two new species, Ecologica Montenegrina 1 (4), pp. 244-248 : 247-248

Bythiospeum demattiai n. sp.

( Fig. 4­6 )

Type series. Holotype ( ZMH 79882 ): Shell height 1.7 mm, shell width 0.9 mm; Montenegro, Podgorica, spring in village Pričelje, 39 m a.s.l., 20.iv.­25.v.2014 Pešić . Paratypes ( ZMH 79883 ): 9 shells.; 6 shells. coll. Glöer, same data and locality as holotype .

Locus typicus. Montenegro, Pogorica , spring Iverak in village Pričelje, 42°30'17.52''N, 19°13'17.93''E .

Etymology. Named after Willy De Mattia (Trieste) in appreciation of his contribution to the taxonomy of the molluscs.

Description

Shell: Shell elongated cylindrical with a large and obtuse apex ( Figs. 4­6 ). The regularly growing 4.5 whorls are convex with a deep suture. Shell surface smooth. The aperture is ovoid, the outer margin is straight from lateral view ( Fig. 6 ). The umbilicus is closed. The shell height 1.3­1.7 mm, shell width 0.7 mm, apertural/shell height ratio 0.3.

Soft body: unknown.

Differentiating features. The specimens from the Iverak spring are tentaively ascertained to the genus Bythiospeum Bourguignat, 1882 . However, considering that most of the numerous nominal species of Bythiospeum recorded from Europe are known as empty shells ( Haase 1995) only one could expect that phylogenetic relationships within this group (including Paladilhiopsis Pavlović, 1913 as well) may be complex, and the genus is polyphyletic ( Falniowski et al. 2014). Recently we described a new species of Bythiospeum Bourguignat, 1882 based on empty shells from Taban spring, situted only a few kilometres from the type locality of the new “ Bythiospeum “ species. Later on, we collected live specimens ( Pešić and Glöer 2013), and ascribed B. bogici to a new distinct genus Montenegrospeum Pešić & Glöer, 2013 , confirmed by molecular analysis ( Falniowski et al. 2014). Montengrospeum bogici ( Pešić & Glöer 2012) can easily be distinguished by the large dimensions of the shell (2.3 mm vs. 1.7 mm in B. demattiai ) and having the circular, not ovoid, aperture. The shell of the new species resembles those of Devetakia Georgiev & Glöer, 2011 but the body whorl in the species of the latter genus known only from Bulgaria is more protruded ( Georgiev and Glöer 2011).

Distribution. Montenegro; known only from the type locality.

Figures

Figure 4­6. Shell ofBythiospeum demattiai n. sp. 4 = holotype, 5 = paratype, 6 = aperture from the lateral view.