RADOMANIOLA JOVANOVSKAE SP. NOV.

(FIGS 14, 15)

Z o o b a n k r e g i s t r a t i o n: z o o b a n k. org:act: 73C15FFA-001B-4C60-A237-C42DC17B52D8

Etymology: This species is named after Dr Elena Jovanovska, a dedicated researcher of the diatom flora in Lake Ohrid and Lake Prespa, who provided invaluable logistical support for this study.

Type material: Holotype (MNCN 15.05 /200161), 12 paratypes (MNCN 15.05 /200162) in the MNCN collection and> 100 paratypes (UGSB 19517) in the UGSB collection. Type locality: Oteshevo Sirhan Spring, Sirhan, North Macedonia.

Material studied: Oteshevo Sirhan Spring, Sirhan, North Macedonia, 41.0032°N, 20.9357°E, D.L. and S.N., May 2008, MNCN 15.05 /200162 and UGSB 19517 (80% ethanol) .

Diagnosis: Protoconch microsculpture wrinkled; shell aperture slightly oval; central radular tooth formula 7-C-7/1-1; bursa copulatrix ovoid, with a duct longer than bursal length; SR1 pyriform, duct short; SR2 pyriform, duct short; SR1 longer than SR2; penis unpigmented, gradually tapering, shorter than head length, base narrow; nervous system weakly pigmented, moderately concentrated (mean RPG ratio = 0.41).

Description: Shell ovate-conic, 4.00–4.25 whorls, height 2.1–2.9 mm (Fig. 14A–D; Supporting Information, Table S6). Periostracum yellowish. Protoconch ~400 µm wide, 1.5 whorls; nucleus ~150 µm wide; protoconch microsculpture wrinkled (Fig. 14G). Teleoconch whorls convex, with deep sutures; body whorl large, occupying about two-thirds of total shell length. Aperture slightly oval; inner lip thicker than outer lip; peristome margin simple, straight (Fig. 14B). Umbilicus narrow, not covered by the inner lip. Operculum oval, brownish, about two whorls; muscle attachment area oval and located near the nucleus (Fig. 14E, F). Radular length intermediate, ~650µm (~25% of total shell length), with ~55 rows of teeth (Fig. 14H). Central tooth formula 7-C- 7/1-1 (Fig. 14I); basal tongue U-shaped, length about equal to lateral margin. Lateral tooth formula 4-C-4. Inner marginal teeth having 25 or 26 tapered cusps, shortening toward the base. Outer marginal teeth with 23 or 24 sharp cusps (Fig. 14J).

Animal darkly pigmented except for neck and tentacles (Fig. 15F). Ctenidium with 11 or 12 welldeveloped gill filaments, occupying ~50% of pallial cavity length and positioned posteriorly. Osphradium of intermediate width and opposite middle of ctenidium (Fig. 15A). Stomach slightly wider than long, with two chambers almost equal in size; style sac longer than wide, surrounded by an unpigmented intestine (Fig. 15B; Supporting Information, Table S7). Nervous system slightly pigmented, moderately concentrated (mean RPG ratio = 0.41); cerebral ganglia approximately equal in size, presenting small black granules (Fig. 15C).

Female glandular oviduct approximately three times longer than wide. Albumen gland shorter than capsule gland. Bursa copulatrix ovoid, slightly longer than wide. Bursal duct longer than bursal length. Renal oviduct unpigmented, coiled. SR1 pyriform, duct long, joining renal oviduct slightly above the insertion point with bursal duct. SR2 shorter than SR1, pyriform, with a short duct, located on renal oviduct near loop (Figs 15D, E; Supporting Information, Table S8).

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. 15H). Penis unpigmented, gradually tapering, shorter than head length, base narrow, weakly folded along inner edge and with one medial outgrowth on its left side (Fig. 15F, G; Supporting Information, Table S9); penis attached well behind the right eye; penial duct narrow, near outer edge, undulated.

Habitat: This species has been collected from one spring in the watershed of Lake Prespa. Snails occur abundantly on stones together with Ancylus sp.

Remarks: This species is conchologically similar to the geographically proximal R. c. kicavica (Supporting Information, Fig. S2). However, these two taxa can be distinguished anatomically according to a shorter bursal duct, more elongated bursa copulatrix and smaller seminal receptacles in R. jovanovskae, and larger and more tapering penis and larger prostate gland in R. c. kicavica (Supporting Information, Figs S6, S 8). The average sequence divergence between the two taxa was 4% for COI.