The first revision of the carnivorous land snail family Streptaxidae in Laos, with description of three new species (Pulmonata, Stylommatophora, Streptaxidae) Author Inkhavilay, Khamla Author Siriboon, Thanit Author Sutcharit, Chirasak Author Rowson, Ben Author Panha, Somsak text ZooKeys 2016 589 23 53 http://dx.doi.org/10.3897/zookeys.589.7933 journal article http://dx.doi.org/10.3897/zookeys.589.7933 1313-2970-589-23 EECEC70CA98343C486A208CD536293EB EECEC70CA98343C486A208CD536293EB Taxon classification Animalia Pulmonata Streptaxidae Perrottetia unidentata Inkhavilay & Panha sp. n. Figs 1, 5 F-I , 7E, F, 10 A-F , I; Table 1 Type material. Holotype CUMZ 6281 (Fig. 5F). Measurement: shell height 5.3 mm, shell width 9.7 mm and 61/2 whorls. Paratypes CUMZ 6282 (4 shells; Fig. 5G), CUMZ 6283 (1 specimen in ethanol; Figs 7E, F, 9 A-F , I), NHMUK 20160250 (2 shells). Figure 6. Shells of Perrottetia and Indoartemon spp. A, B Perrottetia megadentata sp. n. A holotype CUMZ 6286 with apertural dentition, and B paratype CUMZ 6287. C Indoartemon tridens holotype SMF 108507/1 with apertural dentition D-F Indoartemon diodonta sp. n. D holotype CUMZ 6289 with apertural dentition E paratypes CUMZ 6290, and F specimen from Tam Nang Ann, Tha Khek, Khammouan CUMZ 2691. Figure 7. Genitalia of Haploptychius and Perrottetia species. A, B Haploptychius pellucens CUMZ 2670 A reproductive system, and B insertion of vas deferens into penial sheath C, D Haploptychius porrectus CUMZ 6274 C reproductive system, and D insertion of vas deferens into penial sheath E, F Perrottetia unidentata sp. n. CUMZ 6283 E reproductive system, and F insertion of vas deferens into penial sheath. Figure 8. Genitalia of Haploptychius pellucens A completed reproductive system CUMZ 2670 B, C completed reproductive system with "vaginal caecum" CUMZ 6265, and D aphallic reproductive system CUMZ 6265. Figure 9. Internal sculpture of genitalia of Haploptychius spp. A-F Haploptychius pellucens , CUMZ 2670 A details of atrium surface B arrangement of penial hooks C top view of penial hook (from white square in B) D arrangement of penial hooks E lateral view of penial hook, and F arrangement of undulated parallel vaginal folds. G-M Haploptychius porrectus specimen CUMZ 6275 G details of atrium surface H arrangement of penial hooks in distal area I lateral view of penial hook in distal area J arrangement of penial hooks in proximal area K lateral view of penial hook in proximal area L arrangement of papillae and vaginal folds, and M arrangement of vaginal folds. Other material examined. Tam Than Kaisone, Viengxay, Houaphanh, Laos: CUMZ 6284 (5 shell; Fig. 5I), CUMZ 6285 (2 shells; Fig. 5H). Type locality. The limestone outcrop at Ban Nawit, Viengxay, Houaphanh, Laos ( 20°22'37.3"N , 104°16'43.2"E ) about 700 meters above mean sea level. Diagnosis. This new species differs from Perrottetia daedaleus , Perrotettia aquilonaria , Perrottetia dugasti and Perrottetia messageri from Vietnam in having an oblique shell, a single parietal lamella, widely expanded lip, the last whorl strongly axially deflected, the left side of penultimate whorl well extended beyond the diameter of last whorl, and the distal end of penis with a wing-like structure. The other four species have two parietal lamellae, the last whorl little axially deflected and the left side of penultimate whorl not extended beyond the diameter of the last whorl. For further comparison, Perrottetia daedaleus has an elevated spire, transverse ridges over the entire shell and a basal lamella located deep inside aperture (Fig. 5C); Perrotettia aquilonaria has a smaller shell, elevated spire, bifid columellar lamella, and genitalia with atrial pores and vaginal hooks absent (Fig. 5E); Perrottetia dugasti and Perrottetia messageri have a smooth shell surface, a bifid collumella lamella and a supracolumellar lamella (Fig. 5A, D). Perrottetia gudei from north Vietnam differs from the new species in having an elevated spire, in being less deviated from the vertical axis, and in having thin transverse ridges (see Siriboon et al. 2013 ). Description. Shell. Shell oblique-heliciform, semi-transparent; whorls 61/2 , spire weakly convex with distinct suture. Shell surface glossy with strong transverse ridges on upper shell surface. Embryonic shell large, about 21/2 whorls, with a smooth surface; following whorls regularly coiled. Shell periphery shouldered; last whorl axially deflected; two deep longitudinal furrows present. Aperture semi-ovate; peristome discontinuous; parietal callus thin; lip thickened, broadly expanded and slightly reflected. Apertural dentition with one large, strong and sinuous parietal lamella, one small upper palatal lamella, one palatal lamella, one large basal lamella, one strong columellar lamella, and one small supracolumellar lamella. Umbilicus widely open and shallow (Fig. 5 F-I ). Radula. Each row consists of 26-38 teeth with formula (13-19)-1-(13-19). Central tooth small and triangular, with pointed cusp. Lateral and marginal teeth undifferentiated, lanceolate, unicuspid. Latero-marginal teeth gradually reduce in size, with outermost teeth much smaller and shorter than inner teeth (Fig. 10I). Figure 10. Internal sculpture of genitalia of A-F Perrottetia unidentata sp. n. paratype CUMZ 6283 A details of atrium surface B arrangement of penial hooks C top view of penial hook D lateral view of penial hooks E arrangement of vaginal hooks, and F top view of vaginal hook. Radula morphology of G Haploptychius pellucens specimen CUMZ 2670 H Haploptychius porrectus specimen CUMZ 6275, and I Perrottetia unidentata sp. n. paratype CUMZ 6283. Genital organs. Atrium (at) short. Proximal penis (p) long and slender; distal part near retractor muscle with an expanded wing-like structure (a flat blade on either side of the penis, each about one-tenth of penis length). Penial sheath (ps) thin and extending about one-third of penis length; penial sheath retractor muscle (psr) very thin, originating at atrium and inserting distally on penial sheath (Fig. 7E). Vas deferens (vd) passes through about one-third of penial sheath length before entering into penis apically (Fig. 7F). Penial retractor muscle (pr) thin and long, inserted at penis and vas deferens junction. Internal wall of atrium generally smooth (Fig. 10A). Penial wall densely covered with light brown penial hooks, about 20 hooks/200 μm 2; hooks located on low elliptical penial papillae. Penial hooks small (<0.1 mm in length), slender, expanded at base, tips pointed and curved towards genital orifice (Fig. 10 B-D ). Vagina (v) short, about one-tenth of penis length. Gametolytic duct (gd) a long tube extending as far as albumin gland; gametolytic sac (gs) ovate. Free oviduct (fo) long and cylindrical with equivalent diameter to vagina, tapering distally. Oviduct (ov) enlarged and folded; prostate gland inconspicuous and bound to oviduct. Talon (ta) very small, short and club shape. Hermaphroditic duct (hd) bearing very short and thin seminal vesicle (sv) about one and half times longer than the length from talon to branching point of seminal vesicle (Fig. 7E). Vaginal wall with transparent vaginal hooks (about 10 hooks/200 μm 2). Hooks located on low conical vaginal papillae. Vaginal hooks small (<0.1 mm in length), short and expanded at base; tips pointed and straight to slightly curving away from genital orifice (Fig. 10E, F). Etymology. The specific epithet "unidentata" derived from the Latin words "unus" meaning "one" and "dens" meaning "tooth" . It referred to a single parietal lamella (or teeth) of the new species. Distribution. This species is known only from the type locality, Houaphanh, a limestone karst area. Remarks. Shell variation is evident from specimens from Tam Than Kaisone, about 20 km west of the type locality (Fig. 5H, I; CUMZ 6284, 6285). They are smaller, with a sinuous parietal lamella, and sometimes lack the upper palatal lamella (Table 1). However, only five shells and no living specimens were collected, so we provisionally identifying them as the same species.