Bythinella anatolica Yildirim , Kebapci & Bahadir Koca

Yildirim, Mehmet Zeki, Kebapci, Uemit, Koca, Seval Bahadir & Yuece, Arzu, 2015, New Bythinella (Gastropoda, Bythinellidae) species from western Turkey, ZooKeys 481, pp. 1-13 : 3

Taxon classification Animalia Littorinimorpha Bythinellidae

Bythinella anatolica Yildirim, Kebapci & Bahadir Koca sp. n. Figs 1, 2, 6a

Holotype

(Coll. Yıldırım): SH 2.78 mm, SW 1.67 mm, ah 1.22 mm, aw 1.11 mm. Coll. Yıldırım; TURKEY, Manisa, Çırpıcıdede hill on Spil Mountain, N 38°44.66', E 27°24.30', 17. 07. 2006. Leg. M. Z. Yıldırım. Paratypes: 18 ex. (5 dissected), same data and locality as holotype in Coll. Yıldırım.

Type locality.

A spring below Çırpıcıdede hill on Spil Mountain and its small outflow stream down the hill, Manisa.

Etymology.

Named after Anatolia.

Description.

Shell thin, usually cylindrical-ovoid (SW/SH 57.19%), appearing blackish (owing to darkly pigmented animal), with slightly rough surface; apex blunt, depressed on the left side; having 3 1/2-4 very tumid whorls (more convex the left side), last whorl more inflated, sutures deep. Aperture ovoid or pear shaped, height of the aperture usually greater than penultimate whorl, umbilicus relatively broad and deep, sometimes covered by the outer lip, palatal lip margin not reflected, columellar and parietal margins broadly reflected.

Head black; tentacles unpigmented. Operculum oval and with distinct growth lines.

Penis unpigmented and variable in natural position among individuals (straight to bent or folded), though not in shape. Tubular gland thickened, penial appendix usually very short (varying according to the shell size of the individuals). Bursa copulatrix narrow and elongated, rs1 large and globular in shape. Central tooth of radula with 9 pointed cusps, 1 median and 4 each on sides; lateral margin without any cusps, but undulated; basal lip roundish (Figures 1, 2).

Measurements (n=19): SH: 2.79 mm (min 2.37/max 3.07), SW: 1.65 mm (min 1.37/max 1.92), SH/SW: 1.7 (min 1.59/max 1. 91), SW/SH: 0.58 (min 0.52/max 0.62), ah/SH: 0.44 (min 0.41/max 0.46).

Differential diagnosis: Identified by its larger shell (except Bythinella wilkei sp. n.) and ear–like aperture having reflected margins, a character state not observed in other Turkish species.

Habitat.

Specimens were collected from under the stones in the spring outflow down the hill.

Remarks.

The new species is distinguished from other Turkish species by its larger shell dimensions and ear like shell aperture. Bythinella turca Radoman 1976 is distinguished from Bythinella anatolica sp. n. by its blunter and shorter shell (SH 2,42 ± 0,13; max. 2.81 mm). SW/SH is close to Bythinella istanbulensis sp. n., from which it can be distinguished by its oval shell with convex whorls. Bythinella occasiuncula and Bythinella magdalenae , the geographically most proximate congeners, have smaller shell dimensions, while Bythinella occasiuncula can be identified by the shorter and blunter shell shape and Bythinella magdalenae sp. n. by smoother periphery and shallow sutures.

According to our current knowledge of Peri-Aegean Bythinella species, the area of the Aegean coast of Turkey is a center of diversity for the genus. The Eastern Aegean Islands Ikaria, Kos, Lesbos, and Chios are inhabited by Bythinella kosensis ( Schütt 1980; Bank 1988), while within the provinces of Aydın, İzmir, and Manisa on adjacent Anatolian mainland there are three species ( Bythinella anatolica sp. n., Bythinella magdalenae sp. n. and Bythinella occasiuncula ) geographically isolated from the remainder of the species recorded in Turkey (Figure 7).