Cremnoconchus cingulatus Reid & Aravind & Madhyastha 2013, SP. NOV.
Creators: name: Reid, David G.
name: Aravind, Neelavara Ananthram
name: Madhyastha, Neelavara Ananthram
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Littorinidae
Cremnoconchus
Cremnoconchus cingulatus

description: CREMNOCONCHUS CINGULATUS SP. NOV.  (FIGS 4G, 5O, P, 11Q–U, 13E, F, 14D–I)  
 Types: Holotype ZSI / WGRS /IR.INV-2316 (Fig. 11 R, S); 3 paratypes ZSI / WGRS /IR.INV-2317, 2318, 2319 (Fig. 11Q, T, U); Hulikal Ghat, Udupi Dist., Karnataka, India (13.71742°N 74.99445°E).   
 Etymology: Latin cingulatus, girdled, in reference to sculpture of base.   
 Diagnosis: Shell globular; one rib on base; pseudumbilicus narrow, perforated; surface with satin sheen, microstriae weak or absent. Operculum weakly calcified, no internal ridge. Penis with distal glandular pad, slender filament. Western Karnataka State.   
 Shell (Figs 4G, 11Q–U): Shell H 3.5–6.7 mm. Shape (Table 1) globular; whorls rounded; a weak rib close to suture outlines the flattened sutural area, but rib becomes obsolete on largest shells; suture impressed; peripheral angle absent; apex eroded; base slightly swollen, with thick rib at one-third radius. Columella narrow, wider at base. Pseudumbilicus narrow, 0.2– 0.6 mm, perforated. Surface with satin sheen; spiral striae indistinct or absent, weakly present on base (Fig. 4G). Colour: reddish brown, three indistinct darker brown bands at suture, above periphery and at middle of base; aperture and columella purple-brown, with bands showing through.   
 Animal: Head and tentacles dark grey to black, tip of snout paler; body and sides of foot black. Gills: up to 35 leaflets; black. Operculum (Table 1; Fig. 5O, P): opercular ratio 0.334 –0.472; weakly calcified, concave, no internal ridge. Penis (Fig. 14D–I): base lightly pigmented, wrinkled, solid, with large glandular pad on left of reverse side; invagination about half length of base in ethanol-fixed specimens; filament slender, protruding in ethanol-fixed specimens. Pallial oviduct: as for genus.   
 › Figure 14. Anatomy of Cremnoconchus agumbensis (A–C) and C. cingulatus (D–I), all to same magnification. A, B, D–I, penes (all fixed in ethanol); G–I are abaxial, sectioned and adaxial views of same penis. C, pallial oviduct, with transverse sections in three positions. A–C, Agumbe, Udupi Dist., Karnataka (ZSI/WGRS; shell H: A = 9.5 mm; B = 8.8 mm; C = 9.1 mm). D–I, Hulikal Ghat, Udupi Dist., Karnataka (ZSI/WGRS; shell H: D = 3.5 mm; E = 4.6 mm; F = 3.7 mm; G–I = 4.4 mm). Shading conventions as in Figure 6.   
 Radula (Fig. 13E, F): Relative radula length 1.93– 2.09. Rachidian: length/width 1.10–1.13; 5 cusps (+ 1 outer denticle on either side). Lateral: 5 cusps (sometimes + 1 inner denticle). Inner marginal: 5 cusps. Outer marginal: 4–5 cusps. Major cusp of each of 5 central teeth triangular with rounded and slightly papillose tip; other cusps pointed.   
 Range (Fig. 8): Western Karnataka State, Hulikal Ghat (95 km north-northeast of Mangalore). Records (Supporting Table S1): Karnataka State: Hulikal Ghat, Udupi District (ZSI / WGRS /IR.INV-2316, 2317, 2318, 2319).   
 Habitat and ecology: In rushing stream on rock face and sides of boulders, in fast-flowing water and spray, partly shaded by trees (Fig. 2C). Altitude 475 m.   
 Remarks: The conspicuous rib on the base, narrow but deep pseudumbilicus, and concave, weakly calcified operculum are the distinguishing features of the shell of this species. Except for the basal rib, these characters resemble C. globulus, but their respective penes are diagnostic (Figs 12H–L, 14D–I). Characters of the Cremnoconchus species of Karnataka are summarized in Table 4.   
 There appears to be sexual dimorphism: shells of males are smaller (males: mean ± sample SD = 3.840 ± 0.619 mm, N = 4; females: 5.575 ± 0.697 mm, N = 12) and the aperture is slightly enlarged.   
 At Hulikal Ghat it was found together with C. dwarakii and the two occupied different microhabitats. Cremnoconchus cingulatus occurred on rocks in rushing water, while C. dwarakii was found on mossy rocks dampened only by spray.
description: Published as part of Reid, David G., Aravind, Neelavara Ananthram & Madhyastha, Neelavara Ananthram, 2013, A unique radiation of marine littorinid snails in the freshwater streams of the Western Ghats of India: the genus Cremnoconchus W. T. Blanford, 1869 (Gastropoda: Littorinidae), pp. 93-135 in Zoological Journal of the Linnean Society 167 (1) on pages 124-126, DOI: 10.1111/j.1096-3642.2012.00875.x, http://zenodo.org/record/5292273