Theodoxus gloeri, Odabaşi & Arslan, 2015

Odabaşi, Deniz Anil & Arslan, Naime, 2015, Description of a new subterranean nerite: Theodoxus gloeri n. sp. with some data on the freshwater gastropod fauna of Balıkdamı Wetland (Sakarya River, Turkey), Ecologica Montenegrina 2 (4), pp. 327-333 : 329-330

Theodoxus gloeri sp. nov.

Description: The hemispherical shell is small, relatively thin and translucent with no pigmentation. Shell sculpture is ornamented with elevations of fine lamella arranged at regular intervals ranging from 15 to 20 in adults. Apex is prominent and smooth at surface. Aperture is semicircular, smooth and without denticles at columellar edge. The shell is up to 2.92 mm (mean: 2.36 mm ±0.31) in height and 3.28 mm (2.95 mm ±0.21) in width (Total No of specimens: 8).

Type Material: 17 ex. from Balıkdamı Wetland- Sakarya River, Eskişehir, Turkey; 39.15277, N 31.61562 E and 39.16116, N 31.61819 E ( Figure 1), 2002, Naime ARSLAN leg. One the specimens regarded as the holotype that it has following dimensions: shell height 2.92 mm, shell width 3.1mm deposited in COMULM–G 0052. Remainders were paratypes from same locality left in either COMULM with the catalog number of G 0053 (7 specimens) or OGUHB in the catalog no: 01759 (9 specimens) .

Remarks: Shell of the Theodoxus gloeri sp. nov. is more smaller than those of Th. pilidei pilidei (4-6 mm, according to Tournouër, 1879: 262, see also Figure 3) and Th. pilidei botenai (much larger than in Th. pilidei pilidei acoording to Wenz 1942: 144 -pl2). Unlike these sibling fossils, Theodoxus gloeri has obviously protruded protoconch with smooth surface and it also has fine lamellar elevations emerging from teleoconch at regular intervals. Empty shells of Theodoxus gloeri were found without opercula. In the literature (i.e. Bandel 2001; Lozouet 2004), there are several ribbed (along with spiral lines) species of Neritimorpha such as Nerita undata , N. plicata and Bourdieria faviai , however, no any other species like two forms of Th. pilidei and Th. gloeri in which have a shell with lamellar structure in parallel with its growth lines.

Habitat: Sampling sites of this species is a large wetland constitutes the headwater of the Sakarya River, located on the bird migration route. This species that was sampled in one station accidentally, is most probably a hypogean form.

Etymology: The species is named after Peter Glöer an outstanding malacologist on freshwater gastropoda.

Faunistic Data

In the present study, a total of 4 Gastropoda species representing 3 genera were identified ( Table 1). Among the seven sampling stations set up in the study area, we have observed gastropod specimens only in three stations which are 1, 3 and 4. Melanopsis buccinoida (Olivier 1801) sampled from station 3 and 4, Theodoxus fluviatilis (Linnaeus 1758) and Pseudamnicola natolica (Küster 1852) specimens were found only in station 1. All species identified during the study are new records for Balıkdamı wetland. One species, Theodoxus gloeri sp. nov. is new to science.