Bythinella sitiensis, Glöer & Hirschfelder, 2019

Glöer, Peter & Hirschfelder, Hans-Jürgen, 2019, New Freshwater molluscs from Crete, Greece (Gastropoda: Hydrobiidae, Bythinellidae, Valvatidae), Ecologica Montenegrina 20, pp. 10-23 : 17-18

Bythinella sitiensis n. sp. ( Figs. 25-28 )

Type material: Holotype ( ZMH 140049 ): Shell height 2.5 mm, shell width 1.6 mm . Paratypes from the type locality Zou: coll. Hirschfelder (2 in ethanol, 1 dried); from sampling site 8 Zakros ZMH (140050, 1 dried, 1 penis), coll. Glöer (2 in ethanol), coll. Hirschfelder (3 in alcohol, 1 dried), coll. Kittel (3 dried) .

Type locality: Crete, Nómos Lasíthi, fountain in Zou, 6 km south of Sitía , 35°09’15.7” N, 26°06’31.5” E, alt. 181 m asl., 29.04.2015 Andrea and Hans-Jürgen Hirschfelder, Klaus Kittel leg. ( Figs. 35 ); together with Pseudamnicola occulta n. sp .

S ampling site 8 (Paratypes): Crete, Nómos Lasíthi, Zákros, Zákros Spring at the western edge of the village, small gutter beside the big source, 35°06’50.1” N, 26°12’49.0” E, alt. 282 m asl., 29.04.2015 Andrea and Hans-Jürgen Hirschfelder, Klaus Kittel leg. ( Figs. 36 ); together with Pseudamnicola occulta n. sp .

Etymology: Bythinella sitiensis n. sp. is named after Sitía in eastern Crete, in whose municipality (Dimos Sitías) the new species was found in two springs.

Description:

Shell: The shell is cylindrical with a small apex. The 4-4.5 whorls are slightly convex with a deep suture. The aperture is ovate, narrowed at the top, with a thickened peristome at the columella. The umbilicus is closed. The shell is 2.5 mm high, 1.5-1.7 mm broad.

Animal: The penis is as long as the penial appendix. The tubular gland becomes thicker at the distal end.

Distribution: Far eastern part of Crete.

Remarks: The distribution map of our three Bythinella species ( Fig. 19 ), we could determine by anatomical features, fits very well with two proposed clades in Szarowska et al. (2016). Clade “CR1” sensu Szarowska et al. (2016) is the true B. cretensis (their sampling site K07 is identical with our site 5), Clade “CR2” sensu Szarowska et al. (2016) should be B. magdalenae n. sp. The sampling site “Epis” (collected by Benke et al. 2011 as “ B. cretensis ”) is 1100 m away from the type locality of B. magdalenae n. sp. In the region of clade “CR3” sensu Szarowska et al. (2016) we did not collect, and the region of East Crete, where we found B. sitiensis n. sp., was not included in the work of Szarowska et al. (2016). Anatomical and shell differences between the studied species are given in the key below.

Figures

Figure 19. The sampling sites of the studied material of Bythinella spp. on Crete. 1-3: Bythinella magdalenae n. sp.: 1: Argiroúpoli (type locality), 2: Ano Méros, 3: Axós; 4-6: Bythinella cretensis: 4: Meso Potámi, 5: Exo Potámi, 6: Sarakina spring; Bythinella sitiensis n. sp.: 7: Zou, 8: Zákros.

Figures 25-28. Bythinella sitiensis n. sp. from Crete. 25: Holotype, 26: male copulatory organ of no. 25, 27, 28: Zákros (paratypes). Abbreviations: p = penis, pa = penial appendix, tg = tubular gland.

Figs. 29-36. Habitats of Bythinella spp. from Crete. 29: Meso Potámi (type locality of B. cretensis), 30: Meso Potámi (B. cretensis together with Ancylus fluviatilis), 31: Exo Potámi (B. cretensis), 32: Argiroúpoli (type locality of B. magdalenae n. sp.), 33: Ano Méros (B. magdalenae n. sp.), 34: Axós (B. magdalenae n. sp.), 35: Zou (tpye locality of B. sitiensis n. sp.), 36: Zákros (B. sitiensis n. sp.).