Motsametia, Vinarski & Palatov & Glöer, 2014

Vinarski, Maxim V., Palatov, Dmitry M. & Glöer, Peter, 2014, Revision of ‘ Horatia’ snails (Mollusca: Gastropoda: Hydrobiidae sensu lato) from South Caucasus with description of two new genera, Journal of Natural History (J. Nat. Hist.) 48 (37 - 38), pp. 2237-2253 : 2248-2251

Genus Motsametia gen. nov.

Type species

Horatia borutzkii Shadin, 1923

Diagnosis

Shell very small (up to 1.5 mm in height), ovate-conical (valvatoid), with relatively large rounded aperture. Whorls (up to 3.5) convex, separated by a deep suture. Surface of protoconch is covered by small and densely situated honeycomb-like pits. Surface of teleoconch covered by rather rough growth lines. Umbilicus deep and narrow, funnel-like. Operculum unknown. Penis slender, elongated, slightly swollen in its middle part. Its lobe situated about 1/3 of the penis length is thin and slim tapered.

Etymology

The name is derived from the Motsameta (‘Martyrdom’) Monastery in Kutaisi ( Georgia) located near the locus typicus of the single species of this genus. Gender – female.

Differential diagnosis

Conchologically, snails of the genus Motsametia are similar to species belonging to the genera Horatia sensu Bodon et al. (2001) and Pontohoratia gen. nov. The differences between Motsametia and Horatia lie in the form and proportions of a penial lobe (short and obtuse in Horatia , thin and slim tapered in Motsametia ). The differences between Motsametia and Pontohoratia lie in different penis morphology (simple penis without penial lobes in Pontohoratia ; penis with a single penial lobe in Motsametia ). In addition, the aperture shape in Pontohoratia is angular, whereas in Motsametia it is almost regularly round.

Distribution and species content

The genus is endemic to South Caucasus (Transcaucasia) and includes the only species: M. borutzkii (Shadin) that is still known from its type locality only. The diagnostic characters of the species coincide with those of the genus. This is a rheophilic species found in underground brooks and springs. The stygobiont community of this cave was partially described by Birstein (1933). Besides Motsametia , it includes several endemic species of crustaceans: Niphargus borutzkyi Birstein, 1933 (Niphargidae) , Troglocaris (Xiphocaridinella) kutaissiana (Sadovsky, 1930) (Atyidae) , and Asellus monticola fontinalis Birstein, 1936 (Asellidae) .

Table 4 provides a morphological comparison of the two genera described here with other taxa of stygobiont valvatiform hydrobiids living in the South European region.

form hydrobiids occurring in the southern part of Europe.