Kaliella dendrobates (Tillier & Bouchet, 1988)

Vermeulen, Jaap J., Liew, Thor-Seng & Schilthuizen, Menno, 2015, Additions to the knowledge of the land snails of Sabah (Malaysia, Borneo), including 48 new species, ZooKeys 531, pp. 1-139 : 87-88

Taxon classification Animalia Stylommatophora Euconulidae

Kaliella dendrobates (Tillier & Bouchet, 1988) Figure 73

Gunongia dendrobates Tillier & Bouchet, 1988: 269. Kaliella dendrobates (Tillier & Bouchet) Liew et al., 2010: Appendix S1 in online Supporting Information. Type from Malaysia, Sabah, Kinabalu N.P.

Examined material from Sabah.

Interior Province. Gunung Trusmadi, Gua Dawaras (leg. M. Schilthuizen, V 13527). West Coast Province. Kinabalu N.P., Carson’s Falls (leg. J.J. Vermeulen, V 12712); Gunting Lagadan (leg. Tachaini Narainan, V 13464); Mesilau trail at 2092 m (leg. T.S. Liew, BOR/MOL 6045); Kotal’s route at 2132 m (leg. T.S. Liew, J. Lapidin, Safrie & Jasilin, BOR/MOL 6044).

Description.

Shell small, very thin, somewhat translucent, (yellowish) brown, rather low-conical with flat sides; apex rounded. Surface shiny. Whorls moderately convex, last whorl rounded at the periphery (angular in juveniles), rounded above and below the periphery. Protoconch whorls convex, with numerous fine, densely placed radial riblets; spiral sculpture subordinate, very fine (just visible at 40 times magnification) to rather distinct, very densely placed grooves, locally present. Teleoconch: above the periphery locally with fine, slightly spaced, narrow spiral grooves cutting into the crests of the radial riblets and subordinate to these, particularly towards the suture and the periphery; below the periphery slightly coarser and slightly more spaced spiral grooves. Radial sculpture: above the periphery distinct, irregularly spaced and locally crowded, somewhat raised growth lines, next to these areas with fine, densely (slightly more densely than the spiral striation) and regularly placed riblets, on the outer whorls locally interrupted by approximately smooth areas; below the periphery with irregularly spaced, slightly raised growth lines only. Umbilicus open, very narrow. Dimensions: Height up to 3.2 mm; width up to 3.9 mm; diameters of the first four whorls 0.65-0.75 mm, c. 1.1 mm, 1.7-1.8 mm, c. 2.65 mm respectively; number of whorls up to c. 5 1/2; height aperture up to 1.6 mm; width aperture up to 1.9 mm. Animal with an obtuse caudal horn. Radula: central 1-cuspid; laterals and marginals similar, serrate with 2 large cones at the tip and a small in between.

Habitat in Sabah and distribution.

Montane and sub-alpine forest on granodiorite and sandstone soil, at 1600-3400 m alt. Sabah: Mount Kinabalu, Gunung Trusmadi. Endemic to Sabah.

Cross diagnosis.

In general shape, sculpture and mode of coiling very similar to Kaliella scandens . Kaliella dendrobates has a much thinner, more shiny shell. The sculpture above the periphery includes irregularly raised growth lines where the fine sculpture of minute radial riblets and even finer spiral grooves is indistinct or entirely absent. In Kaliella scandens raised growth lines are usually absent, and the finer sculpture is continuous. Further differences between the two are found in the radula.

Kaliella micula (Mousson, 1857) ( Zonites micula Mousson, 1857), a widespread species which occurs in Sarawak, resembles Kaliella dendrobates but has a widely rounded apex and slightly convex sides. It is also less densely coiled than Kaliella dendrobates (diameter of the first four whorls c. 1.0 mm, 1.7 mm, 2.8 mm, 4.0 mm respectively in V 13975 from Sarawak, Kuching area, Mount Nambi).

Juveniles of Kaliella dendrobates with a peripheral keel differ from Kaliella calculosa in having a lower conical spire, and a radial sculpture dominated by rather prominent, irregularly spaced, raised growth lines.

We depict a keeled, juvenile specimen with approx. 1 whorl less than the type specimen, which does not have a keel. The sculpture and general shape is similar in both specimens.

The Gunung Trusmadi record is based on a shell consisting of hardly more than a protoconch. Its identity is somewhat uncertain.