Valvata (Tropidina) armeniaca, Walther & Glöer, 2019

Walther, Frank & Glöer, Peter, 2019, A Description of a new Valvata (Mollusca: Valvatidae) from Armenia, Ecologica Montenegrina 24, pp. 1-5 : 2-4

Valvata (Tropidina) armeniaca n. sp. ( Figs. 1-3 , 7-8)

Valvata pulchella [not Studer, 1798] – Akramowski 1968: 26.

Valvata pulchella [not Studer, 1798] – Akramowski 1976: 90, text-fig. 24, pl. 1 fig. 3.

Type material: Holotype: Shell height 1.5 mm, width 2.5 mm, from type locality ( ZMH 59491 ) ; Paratypes: from type locality ( ZMH 59492 , 3 specimens in ethanol); from type locality ( FW 13603 ; 1 dry shell); Ararat Province, Jrahovit , ditch S of the cemetery, 40.0450°N 44.4880°E, 850 m asl., 26 Aug. 2018, F. Walther leg. ( FW 14008 , 1 specimen in ethanol) .

Type locality: Armenia, Armavir Province, bridge over river Kasakh , 1.6 km W of Vagharshapat, 40.1650°N 44.2558°E, 870 m asl., 27 Aug. 2018, F. Walther leg.

Etymology: The new species is named after Armenia, the country of its origin.

Description: The corneous shell has 2.5 circular whorls with a low spire and a blunt apex. The surface has weak growth lines. Within the umbilicus, the penultimate whorl is covered to 75% of its width by the body whorl (measured at the aperture). Shell height 1.2-1.7 mm, diameter 2.2-2.5 mm. The umbilicus is 0.8 mm wide (32-36 % of the shell diameter). The aperture is circular.

Anatomy: The penis is long and cylindrical, tapered at the distal end, which corresponds to the drawing of Akramowski (1976: 89), and as it is in Valvata nowshahrenis ( Glöer & Pešić 2012, fig. 14) and all other Valvata spp. The male and female sex tract in Valvata spp. is very simple and not suitable for species identification.

Differentiating features: Valvata armeniaca n. sp. has a smaller shell with a narrower umbilicus than V. nowsharensis and V. kebapcii Odabaşi, Glöer & Yıldırım, 2015 . The exact differences between the species are displayed in Table 1 .

Distribution: In addition to the type locality, V. armeniaca n. sp, is also known from Jrahovit, from where Akramowski (1976: pl. 1 fig. 3) figured it as V. pulchella . Both localities are in the drainage area of river Aras making it likely that the new species is also distributed in other wetlands of the Aras drainage system. Records of V. pulchella from the lower part of river Aras in Azerbaijan ( Aliyev 2014) could refer to the new species.

Habitat ( Fig. 3 ): Living specimens were collected in dense submerged vegetation. At the type locality river Kasakh has a relatively weak current and carries less water than further upstream due to water withdrawal for the intense agriculture of the surrounding areas. At Jrahovit it was found among partly submersed Nasturtium at a small open spot in the dense reed vegetation of a ditch. Akramowski (1976) mentions the species from weakly flowing water of summer-dry marshes around springs and in drainage canals.

Associated species: Hippeuthis complanatus (Linnaeus, 1758); Lymnaea spec. ; Pisidium spec. , Shadinia terpoghassiani ( Zhadin, 1952) and an unidentified bithyniid.

Discussion: When describing a new Valvata from Armenia it is necessary to discuss the identity of Valvata brandti Westerlund, 1897 , the only Valvata species described from that country before. Although we had no access to the type material we feel entitled to correct some inaccuracies in Haszprunar (2014) concerning the origin and the synonymy of the taxon. The original description of V. brandti is based on two lots. One was collected by A. Brandt in Lake Sevan, while the other was found by L. Młokosiewicz near Lagodekhi in Georgia. Between both localities is a distance of more than 150 km. The Lagodekhi record belongs to Caspicyclotus sieversi , the only Caucasian member of the terrestrial prosobranch family Cyclophoridae and indeed very similar to some Valvata species. The other lot, however, seems to belong to Valvata piscinalis , which is known to occur in Lake Sevan (e.g. Mashkova et al. 2018). The name V. brandti could therefore also be a synonym of V. piscinalis according to a later definition of the taxon by a lectotype. In any case, V. brandti is very different from the species described above.

Figures

Figure 1. The sampling sites of Valvata (Tropidina) armeniaca n.sp. (red squares, 1: type locality, 2: Jharovit).

Figure 2. 1-3: Valvata (Tropidina) armeniaca n.sp. (holotype) and 4-6: Valvata (Tropidina) nowshahrensis, 7-8: Valvata (Tropidina) kebapcii (holotype), 9-10: Valvata (Tropidina) armeniaca n.sp. (paratype) photographed under ethanol to show the characteristic mantle pigmentation.

Figure 3. River Kasakh at the type locality of Valvata (Tropidina) armeniaca n.sp.