A new genus and species of Hydrobiidae Stimpson, 1865 (Caenogastropoda, Truncatelloidea) from Peloponnese, Greece Author Falniowski, Andrzej https://orcid.org/0000-0002-3899-6857 Department of Malacology, Institute of Zoology and Biomedical Research, Jagiellonian University, ul. Gronostajowa 9, 30 - 387 Krakow, Poland Author Grego, Jozef Horna Micina 219, SK- 97401 Banska Bystrica, Slovakia Author Rysiewska, Aleksandra Department of Malacology, Institute of Zoology and Biomedical Research, Jagiellonian University, ul. Gronostajowa 9, 30 - 387 Krakow, Poland Author Osikowski, Artur https://orcid.org/0000-0001-6646-2687 Department of Animal Reproduction, Anatomy and Genomics, University of Agriculture in Krakow, al. Mickiewicza 24 / 28, 30 - 059 Krakow, Poland Author Hofman, Sebastian https://orcid.org/0000-0001-6044-3055 Department of Comparative Anatomy, Institute of Zoology and Biomedical Research, Jagiellonian University, ul. Gronostajowa 9, 30 - 387 Krakow, Poland s.hofman@uj.edu.pl text ZooKeys 2021 2021-05-18 1037 161 179 http://dx.doi.org/10.3897/zookeys.1037.64038 journal article http://dx.doi.org/10.3897/zookeys.1037.64038 1313-2970-1037-161 2B9A12E165A943EE9978C02CCDBCD4EA 69E6E14BAB435D40876BE2CF073E0BFF 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. Eross 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. Figure 6. Protoconchs of Achaiohydrobia moreana . Scale bar: 200 μm . 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 Figure 7. Radulae of Achaiohydrobia moreana . Scale bar: 25 μm . 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.