Sarika inferospira Pholyotha & Panha, 2020

Pholyotha, Arthit, Sutcharit, Chirasak, Tongkerd, Piyoros & Panha, Somsak, 2020, Integrative taxonomic revision of the land snail genus Sarika Godwin-Austen, 1907 in Thailand, with descriptions of nine new species (Eupulmonata, Ariophantidae), ZooKeys 976, pp. 1-100 : 1

publication ID

https://dx.doi.org/10.3897/zookeys.976.53859

publication LSID

lsid:zoobank.org:pub:B755A1D5-D42D-4CA5-89BE-10C11EAB4580

persistent identifier

https://treatment.plazi.org/id/CE4EE71E-7FCE-4696-BDEE-A145178CBAE3

taxon LSID

lsid:zoobank.org:act:CE4EE71E-7FCE-4696-BDEE-A145178CBAE3

treatment provided by

ZooKeys by Pensoft

scientific name

Sarika inferospira Pholyotha & Panha
status

sp. nov.

Sarika inferospira Pholyotha & Panha sp. nov. Figs 1 View Figure 1 , 32 View Figure 32 , 33D View Figure 33 , 38A, B View Figure 38 , 39A, B View Figure 39 , 40 View Figure 40 , 43C View Figure 43

Type material.

Holotype CUMZ 7254 (Fig. 38A View Figure 38 , width 25.3 mm, height 11.5 mm). Paratypes CUMZ 7255 (two shells and 13 specimens preserved in ethanol; Fig. 38B View Figure 38 , width 24.8 mm, height 11.0 mm) CUMZ 7256 (four shells), 7257 (four specimens preserved in ethanol), NHMUK 20200285 (two shells).

Type locality.

Wat Tham Sai Thong, Nong Kung Si, Kalasin, Thailand, 16°50'11.3"N, 103°14'18.7"E.

Diagnosis.

Shell large, strongly depressed, very pale yellowish brown with shouldered body whorl. Animal with grey colour 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 two spines and a series of several branching spines occurring continually to the middle region; middle region becoming smooth, spineless and then terminal part approximately half of its length with a series of branching spines.

Description.

Shell. Shell strongly depressed, large size (shell width up to 29.3 mm, shell height up to 13.9 mm) and thin. Surface smooth and polished; shell colour very pale yellowish brown. Whorls 6- 6½, increasing regularly; body whorl large and shouldered. Spire slightly elevated; suture impressed. Aperture crescent-shaped and obliquely opened. Peristome simple. Columellar margin simple and slightly reflected near umbilicus. Umbilicus narrowly opened (Fig. 38A, B View Figure 38 ).

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 cylindrical and approximately the as long as penis. Epiphallic caecum short, straight, diameter larger than epiphallus, and located near middle of epiphallus. Penial retractor muscle thin and attached at tip of epiphallic caecum. Flagellum long, slender and nearly one and half times of epiphallus length. Vas deferens thin tube connecting distal epiphallus and free oviduct (Fig. 39A, B View Figure 39 ).

Vagina cylindrical, short, and approximately two-third of penis length. Dart apparatus large, long cylindrical and located on atrium at vagina and penis junction. Gametolytic sac enlarged and bulbous; gametolytic duct long cylindrical. Free oviduct cylindrical, approximately two and half times of vagina length (Fig. 39A View Figure 39 ).

Spermatophore long and needle-shaped. Sperm sac enlarged and elongate-oval. Head filament was missing (incomplete spermatophore). Tail filament very long tube and region near sperm sac with two spines. Spine I simple and long. Spine II slightly longer and larger than spine I and branching into many small spinules. Continuously on tail filament with short branching spines arranged in a row, modified to longer branching spines arranged in several rows around middle region, and then become smooth and without spine (Fig. 40A View Figure 40 at yellow line). Terminal part of tail filament (more than ca. one-fourth of its length) with series of long branching spines arranged in opposite rows and tail filament tip with no spine (Fig. 40 View Figure 40 ).

Radula . Teeth with half row formula: 1-(13-14)-59. Central tooth symmetrical tricuspid; lateral teeth asymmetrical tricuspid; marginal teeth elongate bicuspid. Teeth shape is similar to that of S. resplendens . Marginal teeth starting at approximately row number 13 or 14 (Fig. 43C View Figure 43 ).

External features. Animal with reticulated skin and body colour with dark grey above and creamy-grey below. Creamy-grey foot sole and dark creamy-grey caudal horn. Four mantle lobes well developed and pale grey colour. Left shell lobe absent (Fig. 33D View Figure 33 ).

Etymology.

The specific epithet inferospira is derived from the Latin word infer meaning low and the Latin word spira meaning coil. It refers to the strongly depressed shell with low spire.

Distribution.

Sarika inferospira sp. nov. is only known from sandstone habitats with dry dipterocarp forest at the type locality (Fig. 32 View Figure 32 ).

COI analysis.

The ML and BI analyses revealed that the individuals of S. inferospira sp. nov. (n = 3) formed a monophyletic group with very strong support (Fig. 1 View Figure 1 ; BS = 100%, PP = 1), sister group to S. melanospira sp. nov. with only ML support (Fig. 1 View Figure 1 ; BS = 78%). The mean intraspecific genetic distance of S. inferospira sp. nov. was 0.1% (Table 2 View Table 2 ).

Remarks.

Sarika inferospira sp. nov. is distinguished from S. hainesi and S. bocourti by having a strongly depressed shape, shouldered body whorl, and spermatophore smooth or without spine on the middle part of tail filament. Sarika hainesi and S. bocourti have a depressed shell with a higher spire and obtusely angulated body whorl. In addition, the tail filament of spermatophore contains a series of short branching spines more than ca. half of its length in S. hainesi and more than ca. two-thirds of its length in S. bocourti .