Radomaniola szarowskae Delicado & Hauffe 2022, SP. NOV.
Creators: name: Delicado, Diana
name: Hauffe, Torsten
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Hydrobiidae
Radomaniola
Radomaniola szarowskae

description: RADOMANIOLA SZAROWSKAE SP. NOV.
(FIGS 20, 21)
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: 605481A3-A28F-4DC0-B532-9A1534B21887
Etymology: Named after Dr Magdalena Szarowska, in recognition of her many contributions to the evolution of Truncatelloidean gastropods of the Balkan Peninsula, including species of this genus.
Type material: Holotype (MNCN 15.05 /200167), ten paratypes (MNCN 15.05 /200168) in the MNCN collection and 60 paratypes (UGSB 18566) in the UGSB collection. Type locality: source of the Cetina River, Cetina, Croatia.
Material studied: Source of the Cetina River, Cetina, Croatia, 43.9766°N, 16.4301°E, T.H. and D.D., June 2016, MNCN 15.05 /200168 and UGSB 18566 (80% ethanol).
Diagnosis: Shell ovate-conic, 3.5–4.0 whorls (apex often eroded); protoconch microsculpture wrinkled; central radular tooth formula 6-C-6/1-1; bursa copulatrix ovoid, with a duct as long as bursal length; SR1 elongate, duct short; SR2 elongate, same length as SR1, duct short; penis unpigmented, gradually tapering, base wide, shorter than head length; nervous system weakly pigmented, moderately concentrated (mean RPG ratio = 0.47).
Description: Shell ovate-conic, 3.5–4.0 whorls, height 2.3–3.0 mm, apex often eroded (Fig. 20A–D; Supporting Information, Table S6). Periostracum yellowish. Protoconch ~500 µm wide, 1.5 whorls; nucleus ~150 µm wide; protoconch microsculpture pitted (Fig. 20G). Teleoconch whorls convex, with deep sutures; body whorl large, occupying about three-quarters of total shell length. Aperture slightly oval; inner lip thicker than outer lip; peristome margin simple, straight (Fig. 20B). Umbilicus narrow, not covered by the inner lip.
Operculum oval, yellowish, about two whorls; muscle attachment area oval and located near the nucleus (Fig. 20E, F).
Radular length intermediate, ~700 µm (~25% of total shell length), with ~50 rows of teeth (Fig. 20H). Central tooth formula 6-C-6/1-1 (Fig. 20I); basal tongue U-shaped, length about equal to lateral margin. Lateral tooth formula 4-C-4. Inner marginal teeth having 20–25 tapered cusps, shortening toward the base. Outer marginal teeth with 20–24 sharp cusps (Fig. 20J).
Animal darkly pigmented except for neck and tentacles (Fig. 21F). Ctenidium with 13–15 welldeveloped gill filaments, occupying ~50% of pallial cavity length and posteriorly positioned. Osphradium of intermediate width and opposite middle of ctenidium (Fig. 21A). Stomach slightly longer than wide, with two chambers almost equal in size; style sac longer than wide, surrounded by an unpigmented intestine (Fig. 21B; Supporting Information, Table S7). Nervous system slightly pigmented, moderately concentrated (mean RPG ratio = 0.47); cerebral ganglia approximately equal in size, presenting small black granules (Fig. 21C).
Female glandular oviduct approximately three times longer than wide. Albumen gland shorter than capsule gland. Bursa copulatrix ovoid, slightly longer than wide. Bursal duct as long as bursal length. Renal oviduct unpigmented, coiled. SR1 elongate, duct short, joining renal oviduct slightly above the insertion point with bursal duct. SR2 as long as SR1, elongate, with a short duct, located on renal oviduct near loop (Fig. 21D, 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. 21H). Penis unpigmented, gradually tapering, shorter than head length, base wide, weakly folded along inner edge and with one medial outgrowth on its left side (Fig. 21F, G); penis attached close to the right eye; penial duct narrow, near outer edge, almost straight.
Habitat: The source of the Cetina River is a large, deep, karst spring located in the north-western slopes of the Dinara Alps. Snails are distributed on stones submerged at 0.5 m along the shore of the quiet pool formed by the spring waters. The temperature and conductivity of the water are low (9.6 °C and 350 µS/cm) and aquatic vegetation is sparse. Other co-occurring gastropods are Horatia klecakiana (Bourguignat, 1887) and Ancylus sp.
Remarks: This is one of the largest species recorded so far for this genus. Conchologically, R. szarowskae resembles R. c. kicavica, but it differs anatomically from this subspecies according to its larger penis, larger and more globous bursa copulatrix, less concentrated nervous ring and a larger number of cusps on the lateral radular teeth. Phylogenetically, the two taxa are distantly positioned from one another (Fig. 2), and their COI average sequence divergence is 5.6%. Radomaniola szarowskae differs from the phylogenetically and geographically close species R. bosniaca and R. nachtigallae in that it has a more conic and larger shell, more globous and larger bursa copulatrix and in the shape and size of the penis (Supporting Information, Figs S2, S 6, S 8).
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 425-427, DOI: 10.1093/zoolinnean/zlab121, http://zenodo.org/record/7035584