Integrative taxonomic revision of the land snail genus Sarika Godwin-Austen, 1907 in Thailand, with descriptions of nine new species (Eupulmonata, Ariophantidae) Author Pholyotha, Arthit Biological Sciences Program, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand & Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand https://orcid.org/0000-0001-6677-1164 Author Sutcharit, Chirasak Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand jirasak4@yahoo.com Author Tongkerd, Piyoros Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand Author Panha, Somsak Animal Systematics Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand text ZooKeys 2020 976 1 100 http://dx.doi.org/10.3897/zookeys.976.53859 journal article http://dx.doi.org/10.3897/zookeys.976.53859 1313-2970-976-1 B755A1D5D42D4CA589BE10C11EAB4580 1C1677B3CFE65ECEADF5CA56DACD0B9C Sarika pellosa Pholyotha & Panha sp. nov. Figs 1 , 32 , 33F , 38E, F , 41 , 42 , 43E Type material. Holotype CUMZ 7249 (Fig. 38E , width 23.6 mm, height 11.0 mm). Paratypes CUMZ 7517 (two shell and four specimens preserved in ethanol; Fig. 38F , width 23.6 mm, height 11.5 mm) CUMZ 7519 (three specimens preserved in ethanol), NHMUK 20200287 (two shells). Figure 41. Genitalia. A, B Sarika pellosa sp. nov. paratype CUMZ 7517 A general view of the genital system and B internal structure of the penis. White arrowhead indicates the end of the penis. Other material examined. Thailand-Eastern. Tham Saeng Thian, Khlong Hat, Sa Kaeo, 13°18'57.2"N , 102°19'57.2"E : CUMZ 7250. Tham Nam Khao Siva, Khlong Hat, Sa Kaeo, 13°19'15.1"N , 102°19'40.1"E : CUMZ 7251. Limestone outcrop in Khao Chakan, Khao Chakan, Sa Kaeo, 13°39'49.4"N , 102°05'39.7"E : CUMZ 7518. Wat Tham Khao Chakan, Khao Chakan, Sa Kaeo, 13°39'38.0"N , 102°05'02.8"E : CUMZ 7520. Type locality. Tham Phet Pho Thong, Khlong Hat, Sa Kaeo, Thailand, 13°25'02.5"N , 102°19'25.6"E . Diagnosis. Shell large, depressed to strongly depressed, pale brown to dark brown with rounded to weak shouldered body whorl. Animal with blackish body and four mantle lobes. Genitalia with a large straight epiphallic caecum and triangular prism pilasters on inner penial sculpture. Spermatophore: tail filament near sperm sac with three spines and terminal part more than ca. one-third of its length with series of branching spines. Description. Shell . Shell depressed to strongly depressed, large size (shell width up to 24.7 mm, shell height up to 12.0 mm), and thin. Surface smooth and shiny; shell colour very pale brown to dark brown. Whorls 6- 61/2 , increasing regularly; body whorl large and rounded to weak shouldered. Spire moderately elevated; suture impressed. Aperture crescent-shaped and obliquely opened. Peristome simple. Columellar margin simple and slightly reflected near umbilicus. Umbilicus narrowly opened (Fig. 38E, F ). Genital organs . Atrium short. Penis cylindrical with thin penial sheath covering proximal penis. Inner sculpture of penis proximally more than ca. half of penial chamber with very finely longitudinal penial pilasters to nearly smooth surface, and then gradually transformed from small to large rhomboid pilasters with acute angle on top (triangular prism). Epiphallus enlarged cylindrical and approximately two times penis length. Epiphallic caecum large, straight, similar to epiphallus diameter and located near middle of epiphallus. Penial retractor muscle thin and attached at tip of epiphallic caecum. Flagellum long and enlarged approximately as long as epiphallus. Vas deferens thin tube connecting distal epiphallus and free oviduct (Fig. 41 ). Figure 42. Spermatophore of Sarika pellosa sp. nov. paratype CUMZ 7517 A general view of the spermatophore B head filament, and C-E tail filament showing C three spines located close to the sperm sac, D region with and without branching spines, and E branching spines on the tip region. Yellow arrowhead indicates the end of the spines from the tip. Vagina long cylindrical and approximately twice as long as penis. Dart apparatus large, long cylindrical, and located on atrium at vagina and penis junction. Gametolytic sac enlarged and bulbous; gametolytic duct enlarged cylindrical (spermatophore inside). Free oviduct cylindrical, slightly shorter than vagina (Fig. 41A ). Spermatophore long and needle-shaped. Sperm sac enlarged and elongate-oval. Head filament was missing (incomplete spermatophore). Tail filament very long tube; region near sperm sac with three spines. Spine I simple and rather short. Spine II large and long, and most of branching spines probably missing. Spine III smaller than spine II, branching into small spines and spinules. Region furthest away smooth and without spine; terminal part (more than ca. one-third of its length) with series of long branching spines arranged in a row or encircled the tail filament tip (Fig. 42 ). Radula . Teeth with half row formula: 1-(15-16)-50. Central tooth symmetrical tricuspid; lateral teeth asymmetrical tricuspid; marginal teeth elongate bicuspid. Marginal teeth starting at approximately row number 15 or 16 (Fig. 43E ). Figure 43. Representative SEM images of the radula. A Sarika hainesi specimen CUMZ 7237 B S. bocourti specimen CUMZ 7597 C S. inferospira sp. nov. paratype CUMZ 7255 D S. melanospira sp. nov. paratype CUMZ 7243, and E S. pellosa sp. nov. specimen CUMZ 7251. Central tooth indicated by 'C' ; Yellow colour indicates lateral teeth with the transition to marginal teeth. External features . Animal with reticulated skin and blackish body. Foot sole and caudal foss present; caudal horn raised. Four mantle lobes well developed and same colour as body. Left shell lobe absent (Fig. 33F ). Etymology. The specific name pellosa is from the Greek word pellos meaning dusky and refers to the blackish body that characterises this species. Distribution. This species is only known from several limestone karsts in Sa Kaeo Province (Fig. 32 ). COI analysis. The ML and BI analyses of S. pellosa sp. nov. (n = 3) revealed that all specimens formed a well-supported clade (Fig. 1 ; BS = 96%, PP = 1), sister group to S. inferospira sp. nov. + S. melanospira sp. nov. + S. bocourti with moderate support (Fig. 1 ; BS = 73%, PP = 0.99). The mean intraspecific genetic distance of S. pellosa sp. nov. was 2.1% (Table 2 ). Remarks. The shell of S. pellosa sp. nov. differs from other species in Sarika hainesi group by having a rounded to very weak shouldered body whorl. In contrast, the shells of S. hainesi and S. bocourti have obtusely angulated body whorls and S. inferospira sp. nov. has a shouldered body whorl. The shell of this new species is generally similar to S. melanospira sp. nov. The distinguishing characters of S. pellosa sp. nov. are a broader body whorl, larger size of flagellum, vagina and free oviduct, and animal without a dark spiral band, while S. melanospira sp. nov. has a broad body whorl, smaller size of flagellum, vagina and free oviduct, and animal with a dark spiral band below the suture at the body whorl. In addition, the average interspecific sequence divergences between S. pellosa sp. nov. and S. melanospira sp. nov. are fairly high (6.6%). Therefore, we treat them as two separate species.