Renea caucasica, Páll-Gergely & Grego, 2022

Páll-Gergely, Barna & Grego, Jozef, 2022, A Georgian and an Iranian new species of Renea G. Nevill, 1880 enormously extend the genus’s distribution (Gastropoda: Caenogastropoda: Aciculidae), Zootaxa 5188 (6), pp. 596-600 : 597-598

Renea caucasica n. sp.

( Fig. 2 )

Type material. Holotype: (dry shell, SH: 3.7 mm, SW: 1.45 mm), GEORGIA: Samegreglo Reg.: Mukhuri vicinity, road to Lugella , small karst spring well just at left side of road from Mukhuri to Lugella, behind Shurubumu springs, 42°38.985’N 42°12.300’E (locality code: 28x), leg. J. Grego & M. Szekeres, 17 September 2021 ( ISU TM-T002 - H) . Paratypes: same data as for holotype, 2 adult specimens in ethanol (coll. JG) .

Additional material. 1 juvenile specimen in ethanol, same data as for holotype, coll. JG .

Diagnosis. A spindle-shaped Renea species with relatively widely-spaced, strong ribs (ca. 18 above aperture) without spiral striation, a deep suture, and a strong angularis that runs on ca. half parietal callus.

Description. Shell spindle-shaped with blunt apex, light reddish brown, with ca, 5.5 convex whorls separated by deep suture. Protoconch smooth, glossy, protoconch-teleoconch boundary not clearly discernible, ribbing starts after ca. 0.75 whorls. Teleoconch strongly ribbed, ribs equidistant, widely-spaced compared to most congeners, with ca. 18 ribs above aperture in apertural view. Spiral striation absent. Apertural rim asymmetrically arched in lateral view: its upper part leans slightly deeper backwards than lower part. A sinulus not clearly marked, parieto-palatal junction pointed. Palatal wall normally curved. Neck bulge missing. Peristome purple, not expanded on palatal part, but slightly expanded on basal and columellar area, where it covers umbilicus. Parietal callus visible, it is the direct continuation of columellar peristome without any interruption. Angularis whitish, strong, pointed, elongated triangular, situated on the anterior edge of parietal callus, starts ca. at middle of parietal callus and gradually increases towards parieto-palatal junction until it reaches its maximal height. Between highest point of angularis and palatal wall there is a narrow channel with much weaker parietal callus (even ribs of body whorls visible). Umbilicus is covered by reflected peristome.

Measurements (in mm). SH = 3.7–3.8, SW = 1.45–1.5 (n = 3).

Differential diagnosis. This new species differs from all other Renea species by the spindle-shaped (not conical or cylindrical) shell shape, and the angularis, that runs along the parietal callus instead of being oriented into the aperture as in Southern European Renea species ( Renea berica Niero, Nardi & Braccia, 2012 , Renea kobelti (A. J. Wagner, 1910) , Renea spectabilis (Rossmässler, 1839) ( Renea veneta (Pirona, 1865)) . Moreover, the rib density is lower than in the majority of Renea species, and most species has dense spiral striation between the ribs ( Boeters et al. 1989, Niero et al. 2012, Lika et al. 2021). See also under Renea nemethi n. sp.

Etymology. Named after the Caucasus Mountains where it was found.

Figures

FIGURE 2. Renea caucasica n. sp., holotype. Photos: B. Páll-Gergely.