Sarika dohrniana (Pfeiffer, 1860)

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

Sarika dohrniana (Pfeiffer, 1860) Figs 1 , 6 , 9D , 11C, D , 14A, B , 15 , 30B

Helix (Nanina) dohrniana Pfeiffer, 1860: 136. Type locality: “Siam” [Thailand]. Pfeiffer 1868: 97.

Nanina (Hemiplecta) dohrniana : Martens 1867: 72.

Nanina (Xestina) dohrniana : Tryon 1886: 83, pl. 16, figs 23, 24.

Nanina (Xesta) dohrniana : Fischer and Dautzenberg 1904: 394.

Ariophanta (Hemiplecta) dohrniana : Fischer 1891: 22.

Sarika dohrniana : Godwin-Austen 1907: 181, 182; Sutcharit and Panha 2008: 96.

Type material.

Syntypes NHMUK ex. Cuming collection: 20160046 (three shells; Fig. 11C ) from Siam [Thailand].

Other material examined.

Thailand. Siam: NHMUK 1903.7.1.464 (one shell). Thailand-Northeastern. Dong Phya Fai, Siam: NHMUK 1903.7.1.1702 ex. Flower collection (two shells). Wat Thep Phithak Punnaram, Pak Chong, Nakhon Ratchasima, 14°36'57.3"N, 101°15'34.3"E: CUMZ 7616. Wat Tham Thian Chai Chonprathan, Pak Chong, Nakhon Ratchasima, 14°37'07.5"N, 101°18'15.5"E: CUMZ 7621. Wat Tham Praput, Pak Chong, Nakhon Ratchasima, 14°35'37.6"N, 101°40'16.8"E: CUMZ 7619. Wat Tham Pin Kaeo, Pak Chong, Nakhon Ratchasima, 14°36'26.4"N, 101°37'11.4"E: CUMZ 7622. Wat Tham Sap Muet, Pak Chong, Nakhon Ratchasima, 14°47'14.0"N, 101°25'49.8"E: CUMZ 7624. Wat Tham Santitham, Pak Chong, Nakhon Ratchasima, 14°34'29.7"N, 101°37'36.5"E: CUMZ 7625. Muak Lek Waterfall, Pak Chong, Nakhon Ratchasima, 14°38'36.1"N, 101°12'17.4"E: CUMZ 7632. Mountain area near Lam Phra Phloeng Dam, Pak Thong Chai, Nakhon Ratchasima, 14°32'33.0"N, 101°45'37.0"E: CUMZ 7631. Thailand-Central. Wat Tham Mongkut, Phra Phutthabat, Saraburi, 14°40'40.9"N, 100°50'33.6"E: CUMZ 7620. Tham Rakhang-Tham Kin Non, Phra Phutthabat, Saraburi, 14°42'57.1"N, 100°47'49.3"E: CUMZ 7626. Saeng Tham Cave, Muak Lek, Saraburi: CUMZ 7613. Wat Tham Tham Osot, Muak Lek, Saraburi, 14°42'35.7"N, 101°07'01.5"E: CUMZ 7627. Wat Tham Rattana Buppha, Muak Lek, Saraburi, 14°41'35.3"N, 101°07'50.5"E: CUMZ 7629. Wat Tham Si Wilai, Chaloem Phra Kiat, Saraburi, 14°42'44.4"N, 100°51'58.5"E: CUMZ 7630, 7633. Wat Tham Phra Phothisat, Kaeng Khoi, Saraburi, 14°34'33.2"N, 101°08'42.6"E: CUMZ 7614, 7618. Wat Tham Khao Kaeo, Kaeng Khoi, Saraburi, 14°36'16.9"N, 101°05'36.6"E: CUMZ 7628. Mountain area in Thap Kwang, Kaeng Khoi, Saraburi, 14°31'32.7"N, 101°01'37.4"E: CUMZ 7635. Wat Tham Mongkol Nimit, Mueang, Lopburi, 14°49'34.1"N, 100°45'28.4"E: CUMZ 7611 (Fig. 11D ). Wat Pa Tham Sua, Mueang, Lopburi, 14°48'48.6"N, 100°47'03.9"E: CUMZ 7612. Wat Tham Phrathat, Mueang, Lopburi, 14°48'23.6"N, 100°49'29.7"E: CUMZ 7615. Wat Tham Muang, Mueang, Lopburi, 14°48'07.1"N, 100°46'40.3"E: CUMZ 7617. Wat Tham Phrom Sawat, Phatthana Nikhom, Lopburi, 14°45'32.0"N, 100°56'22.4"E: CUMZ 7623. Wat Pa Tham Ariyasatsi, Phatthana Nikhom, Lopburi, 14°47'58.3"N, 100°53'10.0"E: CUMZ 7636. Mountain area in Chai Badan, Chai Badan, Lopburi, 14°59'21.2"N, 100°52'34.3"E: CUMZ 7634.

Diagnosis.

Shell large to very large, depressed to conoid-depressed and rounded to slightly obtusely angulated body whorl. Animal with pale grey body and five mantle lobes. Genitalia with straight epiphallic caecum and small cuboidal penial pilasters. Spermatophore: head filament with irregularly smooth longitudinal ridges; tail filament near sperm sac with two spines and terminal part more than ca. one-eighth of its length with series of several branching spines.

Description.

Shell. Shell depressed to conoid-depressed, large to very large size (shell width up to 33.2 mm, shell height up to 18.9 mm) and rather thin to slightly solid. Shell surface smooth, rather coarse above periphery; shell colour yellowish brown to dark brown. Whorls 6- 6½, increasing regularly; body whorl large and rounded to slightly obtusely angulated. Spire very much elevated; suture impressed. Aperture crescent-shaped and obliquely opened. Peristome simple. Columellar margin simple and slightly reflected near umbilicus. Umbilicus narrowly opened (Fig. 11C, D ).

Genital organs. Atrium short. Penis cylindrical, elongate and with thin penial sheath covering proximal penis. Inner sculpture of penis proximally more than ca. half of penial chamber with very fine longitudinal penial pilasters, and then transformed to small cuboidal pilasters. Epiphallus cylindrical, as long as penis and slightly narrower than penis. Epiphallic caecum short, straight, approximately same diameter as epiphallus, and located near middle of epiphallus. Penial retractor muscle thin and attached at tip of epiphallic caecum. Flagellum slender and long, approximately as long as epiphallus. Vas deferens thin tube connecting distal epiphallus and free oviduct (Fig. 14A, B ).

Vagina cylindrical and approximately half of penis length. Dart apparatus enlarged, long cylindrical, and located on atrium at vagina and penis junction. Gametolytic sac bulbous; gametolytic duct long and cylindrical. Free oviduct short, approximately half of vagina length, and proximal end encircled with thick tissue (Fig. 14A ).

Spermatophore long and needle-shaped. Sperm sac enlarged and elongate-oval. Head filament gourd shape with irregularly smooth longitudinal ridges. Tail filament very long tube; region near sperm sac with two spines. Spine I simple and little curved. Spine II long and branching into many spinules near the tip. Most of region furthest away smooth and without spine; terminal part (more than ca. one-eighth of its length) with series of short to long branching spines arranged in opposite rows (Fig. 15 ).

Radula . Teeth with half row formula: 1-(19-20)-80. Central tooth symmetrical tricuspid; lateral teeth asymmetrical tricuspid; marginal teeth elongate bicuspid. Marginal teeth starting at ca. row number 19 or 20 (Fig. 30B ).

External features. Animal with reticulated skin and pale grey body, dark creamy mixing with grey foot sole and dark creamy to pale grey caudal horn. Mantle edge well developed and same colour as body (Fig. 9D ).

Distribution.

Sarika dohrniana occurs in the karstic habitats and forested mountains in northeastern and central Thailand (Fig. 6 ).

COI analysis.

The ML and BI analyses of S. dohrniana revealed that three individuals formed a monophyletic group with very strong support (Fig. 1 ; BS = 100%, PP = 1), sister to the rest of most species of Sarika , except for S. solemi sp. nov. + S. dugasti . The mean intraspecific genetic distance of S. dohrniana was 1.7% (Table 2 ).

Remarks.

The remarkable characters of S. dohrniana are its large size, conoid-depressed shell, the coarser shell surface compared to other Sarika species, and the head filament of the spermatophore with its irregularly smooth longitudinal ridges and the two spines on the tail filament near the sperm sac.

Figures

Figure 1. Maximum likelihood tree showing the relationships among species of Sarika based on the mitochondrial COI gene sequences. Numbers by the nodes are the ML bootstrap values (left) and Bayesian posterior probabilities (right); shown only for the nodes supported by ML or BI (≥ 70 % and ≥ 0.95). Each clade colour refers to a genus.

Figure 6. Geographic distribution of Sarika caligina sp. nov., S. dohrniana, S. heptagyra, and S. subheptagyra sp. nov. based on the specimens examined herein.

Figure 9. Living snails of group I: Sarika resplendens group. A Sarika resplendens specimen CUMZ 7843 showing left shell lobe lobes (lsl) B S. resplendens specimen CUMZ 7827 C mating pairs of S. resplendens CUMZ 7876 D S. dohrniana specimen CUMZ 7611 E S. obesior specimen CUMZ 7673 F S. limbata specimen CUMZ 7652. All not to scale.

Figure 11. Shells of group I: Sarika resplendens group. A, B Sarika resplendens A specimen NHMUK 1898.5.18.157 and B specimen CUMZ 7815 C, D S. dohrniana C syntype NHMUK 20160046 and D specimen CUMZ 7611. E, F S. obesior E specimen CUMZ 7675 and F specimen CUMZ 7673.

Figure 14. Genitalia. A, B Sarika dohrniana specimen CUMZ 7633 A general view of the genital system and B internal structure of the penis C, D Sarika obesior specimen CUMZ 7673 C general view of the genital system and D internal structure of penis. White arrowheads indicate the ends of the penes.

Figure 15. Spermatophore of Sarika dohrniana specimen CUMZ 7633 A general view of spermatophore B head filament C, D tail filament showing C two spines located close to the sperm sac and D tip region of tail filament. Yellow arrowhead indicates the end of the spines from the tip of the tail filament.

Figure 30. Representative SEM images of the radula. A Sarika resplendens specimen CUMZ 7851 B S. dohrniana specimen CUMZ 7633 C S. obesior specimen CUMZ 7673 D S. limbata specimen CUMZ 7652 E S. heptagyra specimen CUMZ 7279. Central tooth indicated by ' C'; yellow colour indicates lateral teeth in the transition to marginal teeth.