Radomaniola curta SUBSP. MERIDIONALIS 2022
Creators: name: Delicado, Diana
name: Hauffe, Torsten
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Hydrobiidae
Radomaniola
Radomaniola curta

description: RADOMANIOLA CURTASUBSP.MERIDIONALISSUBSP.
NOV.
(FIGS 4, 5)
Zoobank registration: zoobank.org:act: FAA1D97A- EE43-4DDF-BA3D-462BAFBEE7D7
Etymology: From Latin meridionalis, southern, referring to the distribution of the species relative to its conspecifics.
Type material: Holotype (MNCN 15.05/200152), a dissected animal deposited in the MNCN collection. Type locality: Spring at Bigor Dolenci, North Macedonia.
Material studied: Spring at Bigor Dolenci, North Macedonia, 41.484°N, 20.999°E, C.W., May 2008, MNCN 15.05/200152 (80% ethanol). Canal outflow of spring at Bigor Dolenci, North Macedonia, 41.484°N, 20.999°E, C.W. and D.L., May 2008, UGSB 12958 (80% ethanol). Spring-fed lake near the Kosovitiko River, Lista, Greece, 39.73°N, 20.48°E, Z.E., July 2004, UGSB 14439 (80% ethanol).
Diagnosis: Central radular tooth formula 6-C-6/1-1; penis unpigmented, gradually tapering, shorter than head length and with one medial outgrowth on its left side; nervous system moderately concentrated (RPG ratio = 0.48).
Description: Shell ovate-conic, 4.0–4.5 whorls, height 2.00– 2.25 mm (Fig. 4A–D; Supporting Information, Table S6). Periostracum yellowish. Teleoconch whorls convex, with deep sutures; body whorl large, occupying about three-quarters of total shell length. Protoconch ~450 µm wide, 1.5 whorls; nucleus ~150 µm wide; protoconch microsculpture pitted (Fig. 4G). Aperture slightly oval; inner lip slightly thicker than outer lip; peristome margin simple, straight (Fig. 4B, D). Umbilicus narrow, not covered by the inner lip. Operculum oval, brownish, about two whorls; muscle attachment area oval and located near the nucleus (Fig. 4E, F). Radular length intermediate, ~500 µm (~25% of total shell length), with ~40 rows of teeth (Fig. 4H). Central tooth formula 6-C-6/1-1 (Fig. 4I); basal tongue U-shaped, length about equal to lateral margin. Lateral tooth formula 4-C-4. Inner marginal teeth bearing 25–28 tapered cusps, shortening toward the base. Outer marginal teeth with 19–21 sharp cusps (Fig. 4J).
Animal darkly pigmented except for neck and tentacles (Fig. 5D). Ctenidium with ~15 welldeveloped gill filaments, occupying ~50% of pallial cavity length and positioned posteriorly. Osphradium of intermediate width and opposite middle of ctenidium (Fig. 5A). Stomach approximately as long as wide, with two chambers almost equal in size; style sac longer than wide, surrounded by an unpigmented intestine (Fig. 5B). Nervous system slightly pigmented, almost pale, and moderately concentrated (RPG ratio = 0.48; N = 1); cerebral ganglia approximately equal in size, presenting small black granules (Fig. 5C).
Male genitalia with a prostate gland approximately two times longer than wide, bean shaped; seminal duct entering the middle-posterior region; pallial vas deferens emerging close to its anterior edge (Fig. 5F). Penis unpigmented, gradually tapering, shorter than head length, weakly folded along inner edge and with one medial outgrowth on its left side (Fig. 5D, E); penis attached to the area close to the right eye; penial duct narrow, near outer edge, almost straight.
Habitat: The three localities where this species was found were small, shallow spring-fed waters filled with stones and mud. Snails were found in low abundance on stones at the three localities and co-occurring with Horatia macedonica (KuŠcer, 1937) and Stagnicola palustris (Müller, 1774).
Remarks: Radomaniola curta meridionalis bears a smaller shell than other subspecies of R. curta studied herein, in addition to a wider and shorter penis (Supporting Information, Tables S6 and S9) and an average sequence divergence from other conspecific lineages of 0.6–2.2% for COI. It is also differentiated from the geographically proximate Radomaniola curta subsp. bermius (Reischütz, 1988) in having a shell with smaller umbilicus, larger aperture and more convex spire whorls.
description: Published as part of Delicado, Diana & Hauffe, Torsten, 2022, Shell features and anatomy of the springsnail genus Radomaniola (Caenogastropoda: Hydrobiidae) show a different pace and mode of evolution over five million years, pp. 393-441 in Zoological Journal of the Linnean Society 196 on pages 406-407, DOI: 10.1093/zoolinnean/zlab121, http://zenodo.org/record/7035584