Radomaniola curta, SUBSP. MONTENEGRENSIS, 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 : 407-410

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.7043642
persistent identifier	https://treatment.plazi.org/id/039D87B3-4C2B-1B45-FC84-FA3EFBC176CC
treatment provided by	Plazi
scientific name	Radomaniola curta
status	subsp. nov.

Treatment

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

( FIGS 6 View Figure 6 , 7 View Figure 7 )

Zoobank registration: zoobank.org:act: 6D859A59- 9357-4949-99F4-3960B1E5FBDD

Etymology: The subspecies name refers to the occurrence of this snail in Montenegro.

Type material: Holotype (MNCN 15.05/200157), five paratypes (MNCN 15.05/200158) in the MNCN collection and ~ 50 paratypes (UGSB 19515) in the UGSB collection. Type locality: Drobnica Spring, Reljići, Montenegro.

Material studied: Drobnica Spring, Reljići, Montenegro, 42.2000°N, 19.0593°E, T.H. and C.W., September 2009, MNCN 15.05/200158 and UGSB 19515 (80% ethanol). Maricina Spring, Zabes, Montenegro, 42.2287°N, 19.0907°E, T.H. and C.W., September 2009, UGSB 19051 (80% ethanol). Outflow from the Velje Oko Spring, Gluhi do, Montenegro, 42.2142°N, 19.0512°E, T.H. and C.W., September 2009, UGSB 19043 (80% ethanol).

Diagnosis: Protoconch microsculpture wrinkled; central radular tooth formula 7-C-7/1-1; bursa copulatrix ovoid, with a long duct; distal seminal receptacle (SR1) pyriform, duct medium length; proximal seminal receptacle (SR2) small, pyriform to elongate, duct short; penis unpigmented, gradually tapering, slightly longer than head length, attached to the central area of the head; nervous system moderately concentrated (mean RPG ratio = 0.47).

Description: Shell ovate-conic, 4.0–4.5 whorls, height 2.5–3.0 mm ( Fig. 6A–D View Figure 6 ; Supporting Information, Table S6). Periostracum yellowish. Protoconch ~400 µm wide, 1.5 whorls; nucleus ~150 µm wide; protoconch microsculpture wrinkled ( Fig. 6G View Figure 6 ). 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. 6B View Figure 6 ). Umbilicus narrow, not covered by the inner lip. Operculum oval, brownish, about two whorls; muscle attachment area oval and located near the nucleus ( Fig. 6E, F View Figure 6 ). Radular length intermediate, ~600 µm (~25% of total shell length), with ~60 rows of teeth ( Fig. 6H View Figure 6 ). Central tooth formula 7-C-7/1-1 ( Fig. 6I View Figure 6 ); basal tongue U-shaped, length about equal to lateral margin. Lateral tooth formula 4-C-4. Inner marginal teeth having 24 or 25 tapered cusps, shortening toward the base. Outer marginal teeth with 23–26 sharp cusps ( Fig. 6J View Figure 6 ).

Animal darkly pigmented except for neck and tentacles ( Fig. 7H View Figure 7 ). Ctenidium with 14 or 15 welldeveloped gill filaments, occupying ~50% of pallial cavity length and positioned posteriorly. Osphradium of intermediate width and opposite middle of ctenidium ( Fig. 7A View Figure 7 ). Stomach approximately as long as wide, with two chambers almost equal in size; style sac longer than wide, surrounded by an unpigmented intestine ( Fig. 7B View Figure 7 ; 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. 7C View Figure 7 ).

Female glandular oviduct approximately two times longer than wide. Albumen gland shorter than capsule gland. Bursa copulatrix ovoid, slightly longer than wide. Bursal duct slightly longer than bursal length. Renal oviduct unpigmented, coiled. SR1 pyriform, with duct of medium length, joining renal oviduct at the insertion point with the bursal duct. SR2 shorter than SR1, pyriform to elongate, with a short duct, located on renal oviduct near loop ( Fig. 7D–G View Figure 7 ; Supporting Information, Table S8).

Malegenitaliawithaprostateglandapproximately two times longer than wide, bean shaped; seminal duct entering the middle-posterior region; pallial vas deferens emerging close to its anterior edge ( Fig. 7L View Figure 7 ). Penis unpigmented, gradually tapering, longer than head length, base narrow, weakly folded along inner edge and rarely with one medial outgrowth on its left side ( Fig. 7H–K View Figure 7 ; Supporting Information, Table S9); penis attached to the central area of the head; penial duct narrow, near outer edge, almost straight.

Habitat: Radomaniola curta montenegrensis has been collected from three closely proximal rheocrene springs located close to the Lake Scutari. These springs were of cold, low water flow. Snails were abundant on stones and in the mud at all localities. No direct co-occurring species was found.

Remarks: All three studied populations of R. c. montenegrensis varied in shell size and shape and penis size ( Figs 6 View Figure 6 , 7 View Figure 7 ; Supporting Information, Tables S6 and S9). Despite their morphological differentiation, COI sequence divergence was low (0.1%). This subspecies differs from the geographically proximate R. c. curta , Radomaniola curta anagastica ( Radoman, 1973) and Radomaniola curta maxima subsp. nov. in its shorter and more ovate shell (see Radoman, 1983; Supporting Information, Table S6), smaller bursa copulatrix (Supporting Information, Table S8), a shorter distance between seminal receptacles and an average sequence divergence with R. c. curta and R. c. maxima of 1.2–2.5% for COI. The COI sequence divergence between R. c. montenegrensis and one individual from the type locality area of R. c. anagastica, sequenced by Falniowski et al. (2012) (GenBank accession number: KC011773 View Materials ), was substantial (5.4%).