Radomaniola curta, SUBSP. MERIDIONALIS, 2022

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, Zoological Journal of the Linnean Society 196, pp. 393-441 : 406-407

publication ID	https://doi.org/ 10.1093/zoolinnean/zlab121
publication LSID	lsid:zoobank.org:pub:89452E3C-3AFE-449C-93C6-24EEE19AE45D
DOI	https://doi.org/10.5281/zenodo.7043640
persistent identifier	https://treatment.plazi.org/id/039D87B3-4C28-1B5A-FF19-FAC4FEF377DA
treatment provided by	Plazi
scientific name	Radomaniola curta
status	SUBSP.

Treatment

RADOMANIOLA CURTA SUBSP. MERIDIONALIS SUBSP. View in CoL NOV.

( FIGS 4 View Figure 4 , 5 View Figure 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 View Figure 4 ; 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 View Figure 4 ). Aperture slightly oval; inner lip slightly thicker than outer lip; peristome margin simple, straight ( Fig. 4B, D View Figure 4 ). 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 View Figure 4 ). Radular length intermediate, ~500 µm (~25% of total shell length), with ~40 rows of teeth ( Fig. 4H View Figure 4 ). Central tooth formula 6-C-6/1-1 ( Fig. 4I View Figure 4 ); 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 View Figure 4 ).

Animal darkly pigmented except for neck and tentacles ( Fig. 5D View Figure 5 ). 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 View Figure 5 ). 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 View Figure 5 ). 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 View Figure 5 ).

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 View Figure 5 ). 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 View Figure 5 ); 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.