Monacha (Monacha) ocellata (ROTH 1839)

Irikov, A., 2008, Genus Monacha FITZINGER 1833 in Bulgaria (Gastropoda, Pulmonata, Hygromiidae), Linzer biologische Beiträge 40 (1), pp. 785-811 : 792-793

Monacha (Monacha) ocellata (ROTH 1839)

1821 Helix (Helicella) olivieri FÉRRUSAC: 47 [partim, nomen nudum].

1839 Helix olivieri var. ocellata ROTH : 14. Locus typicus: "Byzantii", Turkey.

Published for Bulgaria from: present study.

The species is registered in Bulgaria from one locality only ( Map 4 ).

Researched material and locality ( Map 4 ): South Black Sea Coast: sand coast Arkutino, near by marsh-reserve Arkutino, between Sozopol and Primorsko ( NG 58), 2-3 m alt., 72 specimens, 12.09.2005 and 23.06.2006, leg. IRIKOV.

Shell (Fig. 9): Measurements (n = 72), D: 10.5-16.2 mm, x = 12.4 mm; H: 7.7-12.0 mm, x = 9.0 mm; D/H = 1.3-1.4 mm, x = 1.38 mm.

Genitalia (Fig. 3): The measurements of some sections of the genitalia are compiled in Table 2 and the variation of the proportions of some sections of the genitalia is represent in Table 3.

Vertical distribution: In Bulgaria on the Black Sea Coast on several metres of the sea.

Ecological data: The species live on Black Sea Coast at xerothermal ecological conditions in the summer and comparatively mild and humid winter. There in the same habitat occur M. solidior too, but in difference of her M. ocellata inhabit area more distant of the gritty dunes, where the psamophytic grassy vegetation is a quite abundant. Here perennial plants almost entirely cover the gritty coast. In difference of M. solidior , which rarely may be found to be active on the plants in summertime (see below M. solidior ), M. ocellata make huge aggregates among the psamophytic vegetation and in determinate periods the animals are active. In the same locality M. ocellata form the largest aggregates on artificial planted introduced plants of Genus Opuncia sp. These Opuncia occurs in large numbers in nearly located island "Zmiyski Ostrov", where are introduced in the beginning of XX century, and subsequently are carried on the Black Sea Coast.

We don’t find M. ocellata nowhere elsewhere in the southern Black Sea Coast. We assume that it is possible the species was carried there from the southern areas together with the plants of Genus Opuncia. In the same locality already exist one introduced in the Bulgarian malacofauna species – Cochlicella acuta, reported at first by HUDEC & VASATKO (1973). The manner of introduction is still vague and probably transferring was made accidentally, but the species is survivor and formed small stable population.

Xerophilic, thermophilic, drought-resistant species.

Zoogeography: Asia Minor subelement, Subiranian element, Southwestern Asiatic complex.

Figures

Map 4. Distribution of Monacha (Monacha) ocellata (ROTH 1839) (UTM-grid, 10 km-squares).