Bythinella cretensis Schütt, 1980

Glöer, Peter & Hirschfelder, Hans-Jürgen, 2019, New Freshwater molluscs from Crete, Greece (Gastropoda: Hydrobiidae, Bythinellidae, Valvatidae), Ecologica Montenegrina 20, pp. 10-23 : 15-16

Bythinella cretensis Schütt, 1980 ( Figs. 14-18 )

Type locality: “ Insel Kreta : Quellbach in Mesa Potami, 25°31’ N, 35°13’ E, 900 m NN, 11.2-14.1 °C. [Remark: Schütt confused the coordinates N/E]

Description:

Shell: The shell is cylindrical with a small apex. The 4-4.5 whorls are slightly convex with a deep suture. The body whorl is prominent, especially in height. The aperture is ovate, narrowed at the top, with a peristome thickened at the columella. The umbilicus is slit-like to closed. The shell is up to 3.3 mm high and 1.5-2.0 mm broad.

Animal: The penis is shorter than the penial appendix. The tubular gland has the same width over the full length.

Sampling sites (numbers refer to the map in Fig. 19 ):

4: Crete, Nómos Lasíthi, Meso Potámi (type locality), spring 500 m W of the village, 05.05.2015 Andrea and Hans-Jürgen Hirschfelder, Klaus Kittel leg.; together with Ancylus fluviatilis (O.F. Müller 1774) ( Figs. 29, 30 ) .

5. Crete, Nómos Lasíthi, Exo Potámi (2.4 km E of Meso Potámi), fountain (two pipes) and outflow into a small water basin, 05.05.2015 Andrea and Hans-Jürgen Hirschfelder, Klaus Kittel leg. ( Fig. 31 ). This spring is identical to sampling site K07 in Szarowska et al. (2016).

6: Crete, Nómos Lasíthi, Sarakina spring 800 m W of Males (8.8 km N of Mýrtos), 23.04.2015 Andrea and Hans-Jürgen Hirschfelder, Klaus Kittel leg.

A very small Bythinella population was also found 5 km W of Meso Potámi in a seeping spring at the monastery Kardiotisa, but the sample was too small for anatomical investigation. So the status of this population remains unknown.

Distribution: Lasíthi highlands and east central Crete.

Remarks: For discussion see under Bythinella sitiensis n. sp.

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 14-18. Bythinella cretensis. 14: Holotype, 15: specimen from Exo Potami, 16: specimen from Meso Potami (topotype), 17: penis in situ, 18: penis with tubular gland. Abbreviations: e = eye, p = penis, pa = penial appendix, t = tentacle, 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.).