Achaiohydrobia moreana Hofman & Grego, 2021

Falniowski, Andrzej, Grego, Jozef, Rysiewska, Aleksandra, Osikowski, Artur & Hofman, Sebastian, 2021, A new genus and species of Hydrobiidae Stimpson, 1865 (Caenogastropoda, Truncatelloidea) from Peloponnese, Greece, ZooKeys 1037, pp. 161-179 : 161

Achaiohydrobia moreana Hofman & Grego sp. nov. Figure 2

Holotype.

GNHM 39589, leg. M. Szarowska and A. Falniowski, 16.07.2009; ethanol-fixed specimen (Fig. 2A ), brackish water of Moustos spring, 2 km N of Aghios Andreas, Arkadia, eastern Peloponnese, Greece (37.3845, 22.7444), creeping on the stones and gravel.

Paratypes.

Ten paratypes, ethanol-fixed, in the collection of the Department of Malacology of Jagiellonian University. GNHM 39590/20, HNHM Moll.105301/30 wet specimens; NHMW 113630/10 wet specimens; NHMUK 20210006/10; coll. Erőss 10 wet specimens; coll. Grego 32 wet and 36 dry specimens.

Diagnosis.

Shell broad, ovate-conic with a few flat whorls, rapidly growing and separated by a moderately deep suture; female reproductive organs with a prominent, massive swelling of the spiral of the oviduct; oval bursa copulatrix with the duct longer than the bursa, receptaculum seminis prominent but smaller than the bursa, with the duct slightly distinguishable; penis tapering, widened at the base, without any outgrowths (no glandular lobes) and without the distal papilla (diagnosis the same as for this monotypic genus).

Description.

Shell (Fig. 2 ) broad, thick-walled, brownish, moderately translucent, up to 2.69 mm high and 1.34 mm broad, ovate-conic with about five flat whorls, growing rapidly and separated by moderately deep suture. Conical spire height about 0.25 of the shell height; body whorl prominent and broad. Aperture narrow, elongate-elliptical; peristome complete and thin, in contact with the wall of the body whorl; umbilicus slit-like or completely covered by the parietal lip. Shell surface smooth, with growth lines hardly visible, often corroded.

Measurements of holotype and sequenced and illustrated shells: Table 2 . Shell variability slight (Fig. 2 ).

Protoconch (Fig. 6 ) smooth, often corroded.

Radula (Fig. 7 ) typically taenioglossate, with prominent basal cusps and the central cusp on the central toot; central tooth formula:

3-1-31-1 or (4)3-1-3(4)1-1 or 4-1-41-1

or or

The lateral tooth with 2 - 1 - 2 prominent and broad cusps, especially the bigger one. Inner marginal tooth with about 11, and outer marginal one with 16-19 cusps.

Soft parts morphology and anatomy. The mantle, snout, and tentacles intensively pigmented uniformly black. The female reproductive organs (Fig. 3 ) with a prominent, massive swelling of the spiral of the intensively pigmented black renal oviduct. The bursa copulatrix oval, situated dextro-lateral to the style sac, with the duct longer than the bursa, the receptaculum seminis big, but smaller than the bursa, elongated, with the duct slightly distinguishable from the receptaculum. The penis (Fig. 4 ) tapering, widened at the base, without any nonglandular lobes, no papilla, its proximal section slightly broadened (if at all; see Fig. 4D ).

Derivatio nominis.

The specific epithet Achaiohydrobia moreana refers to Morea, the medieval name of Peloponnese Peninsula.

Figures

Figure 2. Shells of Achaiohydrobia moreana A holotype; shell measurements are shown: a = shell height, b = body whorl breadth, c = aperture height, d = spire height, e = aperture breadth, α = apex angle, β = angle between body whorl suture and horizontal surface. Scale bar: 1 mm.

Figure 3. Renal and pallial section of female reproductive organs of Achaiohydrobia moreana; drawing not to the scale (bc - bursa copulatrix, cbc - duct of the bursa, ov - oviduct, ovs - spiral of renal oviduct, rs - receptaculum seminis). Scale bar: 200 μm.

Figure 4. Penis of Achaiohydrobia moreana. Scale bar: 200 μm.

Figure 6. Protoconchs of Achaiohydrobia moreana. Scale bar: 200 μm.

Figure 7. Radulae of Achaiohydrobia moreana. Scale bar: 25 μm.