Everettia paulbasintali, Liew & Schilthuizen & Vermeulen, 2009

Liew, Thor-Seng, Schilthuizen, Menno & Vermeulen, Jaap Jan, 2009, Systematic revision of the genus Everettia Godwin-Austen, 1891 (Mollusca: Gastropoda: Dyakiidae) in Sabah, northern Borneo, Zoological Journal of the Linnean Society 157 (3), pp. 515-550 : 537

EVERETTIA PAULBASINTALI SP. NOV.

Types: MALAYSIA. State of Sabah. Tawau District, Tawau Hills Park (04°27 ′ N, 117°55 ′ E). Collected by T.- S. Liew and Johny Lapidin. Date: viii.2007, holotype, BOR/MOL 5498, Figure 6D ; four paratypes, two in BMNH 20080628 and two in SP 13060 .

Etymology: This species is named after Paul Basintal, director of Sabah Parks, who has served for over 33 years in Sabah Parks.

Material examined: SABAH – Tabin Wildlife Reserve: BOR/MOL 924, Head Quarters, iii.2000; BOR/MOL 926, Base Camp x.2000; BOR/MOL 962, v.2001; BOR/ MOL 964, v.2001; BOR/MOL 928, Tabin Limestone, x.2000. Danum Valley: BOR/MOL 5271, v.2000; BOR/ MOL 977, v.2000. Imbak Valley: BOR/MOL 927, Transit Camp, vi.2000; BOR/MOL 5264, Transit Camp, vi.2000; SP 12102, vii.2000. Kinabatangan: BOR/MOL 1294, Batu Materis, v.2002; BOR/MOL 2310, Sukau, 2003; BOR/MOL 3597, Gomantong,

i.2004; BOR/MOL 5267, Bod Tai, v.2002. Tawau: BOR/ MOL 1297, Tawau Hills Park, ii.2002; BOR/MOL 4268, Tawau Hills Park, v.2005; SP 12704, Tawau Hills Park, i.2006; SP 12902, Tawau Hills Park, Mount Magdelena, ii.2007; SP 12193, Tawau Hills Park, ix.2002; SP 12195, Tawau Hills Park, ix.2002; SP 12196, Tawau Hills Park, ix.2002; SP 12226, Tawau Hills Park, iii.2003; JJ 1876, Batu Baturong, i.1987; JJ 7592, Batu Baturong, vii.2000; JJ 13165, Tawau Hills Park, v.2005; JJ 13195, Tawau Hills Park, v.2005; JJ 13208, Tawau Hills Park, v.2005. Lahad Datu: JJ 1255, Segama Valley, Kirk’s Cave, ix.1986; JJ 7499, Segama valley, vii.2000; JJ 7789, Segama valley, x.2000.

Diagnostic characteristics: Shell surface with densely placed radial threads.

Description: Shell ( Figs 6D , 10D, E ): large, rather thin, yellowish brown. Spire moderately elevated, outer whorls slightly shouldered below the suture. Periphery slightly shouldered to almost rounded, more distinctly angular in juveniles. Above the periphery, shell silky with very densely placed radial threads and somewhat cut by irregularly spaced spiral grooves. Below the periphery, shell has fine, densely placed spiral grooves. Height up to 19.5 mm; width up to 25.5 mm; diameter of the first three whorls 0.8–0.9, 0.7–0.8, and 1.4–1.5 mm, respectively; number of whorls up to five and a half; height aperture up to 13 mm; width aperture up to 13.5 mm. Genitalia ( Fig. 7C ): maximum length from genital opening to the end of dart-sac (before the visible gland tubules) up to 14 mm. The penis, dart-sac, and vagina with thick muscular walls. P, V, GO, BC, and DS arranged around the short genital atrium, limited space between the openings of each of the genital structures. BC about one-quarter to one-third of total DS length. Animal: black bands on either side of the tentacles separated by a white band that occupies the space between the eye tentacles, and extends backward to the end of the mantle and downward to just below the eye tentacles. Other parts of the animal are covered by regularly spaced oblique dotted belts. The mantle is covered by black irregular markings and followed by regularly spaced radial darker brown bands at the last half whorl.

Distribution and habitat: Primary forest until 1400 m. Sabah: Danum Valley, Kinabatangan, Tabin Wildlife Reserve, Tawau Hills Park, Imbak Valley ( Fig. 5B ).

Remarks: Some of the populations on the left bank of the Segama river (area around Imbak Valley, Danum Valley, and Kinabatangan) have coarser radial threads and these are cut by more closely placed spiral grooves than in the populations with typical sculpture from the right bank of the Segama river (Tabin and Tawau area).

Figures

Figure 5. Distribution maps (Sabah). A, Everettia subconsul in the east and west coast lowland, Everettia jucunda in the west coast, and Everettia occidentalis sp. nov. in the western mountain range; B, Everettia klemmantanica in the central mountain ranges, Everettia interior sp. nov. in the interior area, Everettia paulbasintali sp. nov. in the east coast lowland, Everettia themis in the central mountain ranges; C, Everettia lapidini sp. nov. in the central mountain ranges, Everettia jucundior sp. nov. in the east coast lowland; D, Everettia monticola sp. nov. in the central mountain ranges, Everettia planispira sp. nov. in the eastern and northern parts of Sabah.

Figure 6. Shells. A, Everettia lapidini sp. nov.; B, Everettia klemmantanica; C, Everettia subconsul; D, Everettia paulbasintali sp. nov.; E, Everettia themis; F, Everettia layanglayang sp. nov. Scale bar = 10 mm.

Figure 7. Genitalia. A, Everettia klemmantanica; B, Everettia lapidini sp. nov.; C, Everettia paulbasintali sp. nov.; D, Everettia subconsul; E, Everettia themis; F, Everettia layanglayang sp. nov.; G, Everettia jucundior sp. nov.; H, Everettia interior sp. nov.; I, Everettia corrugata corrugata.

Figure 10. Shell surface sculptures (scanning electron micrographs). A, upper surface of Everettia jasilini sp. nov.; B, underside of E. jasilini sp. nov.; C, upper surface of Everettia safriei sp. nov.; D; underside of Everettia paulbasintali sp. nov.; E, upper surface of E. paulbasintali sp. nov.; F, underside of Everettia klemmantanica; G, upper surface on the fourth whorl of E. klemmantanica; H, upper surface on the second whorl of E. klemmantanica. Scale bar = 100 Mm.