Kaliella calculosa (Gould, 1852)

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 : 76-78

Taxon classification Animalia Stylommatophora Euconulidae

Kaliella calculosa (Gould, 1852) Figure 65, 68

Helix calculosa Gould, 1852: 48. Coneuplecta calculosa (Gould) H. Burrington Baker, 1941: 234; Solem 1988: 544. Kaliella calculosa (Gould) Schilthuizen, 2004: 94; Clements et al. 2008: 2762; Liew et al. 2010: Appendix S1 in online Supporting Information; Schilthuizen et al. 2013: online supplementary data. Type from Society Islands, Tahiti.

Sitala demissa E.A. Smith 1895: 110. Type from Malaysia, Sarawak, Mount Mulu and Busau.

Coneuplecta sitaliformis auct. Schilthuizen et al. 2002: 256.

Examined material from Sabah.

Interior Province. Upper Padas valley, Long Pasia (leg. T.S. Liew & Meckson, BOR/MOL 4357). Crocker Range N.P., West of the km 10 marker on the road Tambunan-Ranau, Mahua Waterfall (leg. J.J. Vermeulen & M. Schilthuizen, V 9736; leg. M. Schilthuizen, BOR/MOL 814). Gunung Trusmadi slopes, Gua Loloposon (leg. J.J. Vermeulen, V 13234). Pun Batu c. 30 km West of Sepulut (leg. J.J. Vermeulen, V 1282). Sepulut valley, Batu Punggul (leg. J.J. Vermeulen, V 1985); Batu Temurung (leg. J.J. Vermeulen, V 8050); Gua Pungiton (leg. J.J. Vermeulen & M. Schilthuizen, V 7560). Sandakan Province. Kinabatangan valley, Gomantong (leg. A. Van Til, BOR/MOL 3269); Batu Keruak (leg. M. Salverda & H. van Oosten, BOR/MOL 2358); Batu Materis (leg. T.S. Liew & B. Elahan, BOR/MOL 2121); Batu Tomanggong Besar (leg. T.S. Liew & B. Elahan, BOR/MOL 2258; leg. M. Schilthuizen, A. van Til & B. Elahan, BOR/MOL 2972); Batu Tomanggong Kecil (leg. T.S. Liew & B. Elahan, BOR/MOL 2058); Unnamed hill near Sukau Police Station (leg. T.S. Liew & B. Elahan, BOR/MOL 2225). Tawau Province. Batu Baturong c. 50 km W.S.W. of Lahad Datu (leg. J.J. Vermeulen & H. Duistermaat, V 14247); Danum Valley (leg. H.A. Rutjes, BOR/MOL 813, BOR/MOL 815; leg. UMS students, BOR/MOL 818). Segama valley, ‘Kirk’s Cave’ 8 km North of Lahad Datu (leg. J.J. Vermeulen, V 14248). West Coast Province. Kinabalu N.P., Poring Hot Springs, Garden near hot springs (leg. J.J. Vermeulen, V 13023); Orchid Garden (leg. J.J. Vermeulen, V 13025); Serinsim (leg. M. Schilthuizen, BOR/MOL 3076); Mesilau trail at 2112 m (leg. T.S. Liew, BOR/MOL 6042). Kota Kinabalu, Kiansom (leg. UMS students, BOR/MOL 816), Papar, Kg. Langsat (leg. T.S. Liew, M. Schilthuizen & F. Disuk, BOR/MOL 3095).

Description.

Shell small, very thin, translucent, pale yellowish-green to pale yellowish-brown, conical with about flat sides. Surface with a silky luster, shiny below the periphery. Whorls somewhat convex, last whorl almost rounded to angular at the periphery, moderately convex below the periphery. Protoconch sculpture: distinct, fine, densely placed radial riblets; spiral sculpture slightly subordinate, equally densely placed or slightly wider spaced grooves cutting into the crests of the radial riblets. Teleoconch: Last whorl with or without a thin peripheral spiral thread coinciding with the suture of the penultimate whorl, above and below this with very fine to rather coarse, moderately to widely spaced, continuous, sometimes rather shallow and wide grooves cutting through the radial riblets. Radial sculpture teleoconch subordinate: above the periphery inconspicuous growth lines, next to these very fine, densely and regularly placed riblets, sometimes on the outer whorls locally interrupted by approximately smooth areas; below the periphery with occasional growth lines only. Umbilicus open, very narrow. Dimensions: Height up to 5.0 mm; width up to 4.6 mm; diameters of the first four whorls 0.65-0.75 mm, 1.15-1.25 mm, 1.75-2.10 mm, 2.6-3.2 mm respectively; number of whorls up to c. 5 3/4; height aperture up to 2.5 mm; width aperture up to 2.7 mm.

Habitat in Sabah and distribution.

Primary and secondary forest on limestone and sandstone soil. Alt. up to 1000 m. Sabah: Crocker Range; Interior; East coast; scattered localities. Distribution elsewhere: From India, Laos, to Australia; Eastwards to Tahiti.

Cross diagnosis.

When fresh, shell thinner and more translucent than the other species in this group, Kaliella dendrophila excepted. Juveniles can be distinguished from that species by the different apical sculpture.

Elsewhere, Kaliella sitaliformis Von Moellendorff 1897, from Java, Bali, and Sulawesi, differs by having a raised spiral sculpture, visible in between the radial riblets, on the outer whorls.

Remarks.

Kaliella calculosa shows considerable variability in the prominence and the density of the spiral sculpture on the teleoconch. SEM-images show that the widest spiral grooves have a distinctly convex bottom; it is as if a thin thread is embedded in the groove.