Corrosella hinzi

Corrosella hinzi (Boeters, 1986) Figs 6–7 Pseudamnicola (Corrosella) hinzi Boeters, 1986: 125, figs 1–3, pl. 18a fig. 1. Pseudamnicola (Corrosella) hinzi – Boeters 1988: 205, figs 62, 72, 85, pl. 2 fig. 21 [partim; non figs 63– 64, 73, 86]. — Boeters et al. 2015: 97. Type material Holotype SPAIN • 1 spec. (sex unknown); Zaragoza, Bulbuente, Balsa de Vargas (at Borja according to Delicado et al. 2010: 101); SMF 257406; designated by Boeters (1986). Paratypes SPAIN • numerous specs; Zaragoza, Bulbuente; SMF 257407 /5 • numerous specs; same data as for preceding; BOE 599, 600 and 1240. Material examined SPAIN – Teruel Province • 8 specs; spring of river park in Calamocha; 40.9261° N, 1.2989° W; 10 Dec. 2009; R.M. Álvarez-Halcón leg.; MNCN 15.05 /63701 • 3 specs; Caminreal, Prado Spring; 40.8452° N, 1.3343° W; 10 Dec. 2009; R.M. Álvarez-Halcón leg.; MNCN 15.05 /63702. – Zaragoza Province • 18 specs; Borja, Balsa de Vargas; 41.8253° N, 1.5525° W; 7 Oct. 2009; R.M. Álvarez-Halcón leg.; MNCN 15.05 /63698 • 17 specs; Borja, Cazuelas Spring; 41.8225° N, 1.5502° W; 14 July 2009; R.M. Álvarez-Halcón leg.; MNCN 15.05 /63699. Description SHELL. Ovate-conic, whorls 4, height 2.75–3.50 mm (Fig. 6A–F); periostracum yellowish, strongly eroded, especially on early whorls; protoconch 1.5 whorls, diameter ca 425 µm, nucleus ca 150 µm wide (Fig. 6G); protoconch microsculpture pitted (Fig. 6H–I); teleoconch whorls convex, separated by deep sutures; peristome orthocline; inner lip thicker than outer lip, partially covering umbilicus; aperture margin slightly sinuate adapically (Fig. 6F). OPERCULUM. Corneous, yellowish, thin, pliable, ellipsoidal, paucispiral with submarginal nucleus, 2.75 whorls; muscle attachment oval, located near nucleus (Fig. 7A–B). RADULA. Length intermediate (20% of total shell length), approximately 8 times as long as wide; having ca 65 rows of teeth. Central tooth formula 6-C-6/1-1, central cusp V-shaped, cutting edge slightly concave (Fig. 7C–D). Lateral tooth formula 4-C-4, central cusp V-shaped, slightly shorter than that central tooth. Inner marginal teeth with 22–24 cusps; outer marginal teeth with 27–29 cusps (Fig. 7E). PIGMENTATION AND ANATOMY. Head dark brown, pigmented from snout to neck (Fig. 7L); lighter pigmentation on neck and tip of the snout; tentacles with medial brown stripe; ocular lobes unpigmented; snout as long as wide, with a strong distal lobation; foot intermediate in length, pigmented dorsally. Ctenidium located anterior in pallial cavity; 14–18 gill filaments, taller than wide. Osphradium intermediate in width, positioned opposite middle of ctenidium (Fig. 7F). Stomach slightly longer than wide; posterior chamber slightly larger than anterior chamber (Fig. 7G); large gastric caecum; style sac longer than wide, encircled by intestine with a small patch of brown pigment. NERVOUS SYSTEM. Dark brown pigmentation, elongated (mean RPG ratio = 0.58); cerebral ganglia equal in size, darker than other ganglia and connectives; supraoesophageal connective ca 6 times as long as pleurosuboesophageal one (Fig. 7H). FEMALE GENITALIA. Capsule gland one-third longer than albumen gland (Fig. 7I); bursa copulatrix pyriform to elongate, folded in U-shaped; bursal duct slightly shorter than bursa; renal oviduct coiled, with 2–3 loops, pigmented to last loop; seminal receptacle pyriform with short duct, positioned slightly above junction of bursal duct and renal oviduct (Fig. 7J–K). MALE GENITALIA. Prostate gland about 3 times as long as wide. Penis gradually tapering, slightly pigmented centrally, with folds along inner edge, attached to the central area of head (Fig. 7L–N). Ecology and distribution The species has been recorded from four spring systems in the Zaragoza and Teruel provinces, northeast Spain. These springs are characterised by clean, well-oxygenated water with low temperatures (15–19°C), conductivity below 1 mS/cm² and a continuous but moderate flow. Specimens occur in high densities on stones, rocks, sandy or gravelly substrates and the submerged parts of aquatic vegetation. Potamopyrgus antipodarum was found co-occurring at all localities except in the River Park Spring in Calamocha, where the species was found alongside Theodoxus sp. Remarks Molecular and morphological studies (Delicado et al. 2013; Boeters et al. 2015), based on specimens collected from the type locality, indicate that C. hinzi does not occur in Pozo Azul (Burgos Province) as previously declared by Boeters (1988). Instead, our study revealed that this population, along with those from nearby areas, belongs to C. navasiana, thereby restricting the distribution of C. hinzi to a few localities in the northeastern Iberian Peninsula. Despite its limited range, anatomical differences exist within C. hinzi: populations from Teruel Province exhibit longer shells and penises (Fig. 7M– N) compared to those from Zaragoza Province, although they share similar female genitalia, nervous systems, and stomach structures.