Taphrenalla diadema (Dall, 1897)

Pholyotha, Arthit, Sutcharit, Chirasak, Tongkerd, Piyoros, Jeratthitikul, Ekgachai & Panha, Somsak, 2021, Integrative systematics reveals the new land-snail genus Taphrenalla (Eupulmonata: Ariophantidae) with a description of nine new species from Thailand, Contributions to Zoology 90 (1), pp. 21-69 : 53-56

Taphrenalla diadema (Dall, 1897)

( figs 1 , 3 , 5, 8A–C, 9A–C, table 6)

Nanina (Macrochlamys) diadema Dall, 1897: 37–38 . Type locality: Prang, Malay Peninsula ; Dall, 1902: 499, pl. 27 figs 1–3 ; Boss, Rosewater, & Ruhoff, 1968: 104.

Macrochlamys diadema: Gude, 1903: 50 .

Syama diadema: Abbott, 1989: 23 , 133 (text figure); Panha, 1996: 102–104, fig. 2b2 (Holotype, USNM 150277) ; Maneevong, 2000: 28–29, fig. 4-2.

Sarika diadema: Sutcharit & Panha, 2008: 95–100 , figs 2a, b , 3a–e , 4a–c.

Material examined. Type material: holotype USNM 150277. Non-type material: Wat Khuha Santayaram (Wat Tham Khao Daeng), Ron Phibun District, Nakhon Si Thammarat (8°14’39.5”N 99°52’00.1”E): CUMZ 7164 (one specimen in ethanol) . Tham Talot, Thung Song District, Nakhon Si Thammarat (8°09’32.3”N 99°40’41.6”E): CUMZ 7165 (16 shells and three specimens in ethanol) . Tham Rad, Thung Song District, Nakhon Si Thammarat (8°02’47.2”N 99°43’45.0”E): CUMZ 7166 (10 shells) and CUMZ 7167 (11 specimens in ethanol) . Wat Tham Phraphut, Ratsada District, Trang (7°57’57.3”N 99°44’41.3”E): CUMZ 7168 (four shells and two specimens in ethanol) . Tham Chang Hai, Mueang District, Trang (7°35’26.6”N 99°40’05.3”E): CUMZ 7169 (nine shells) and CUMZ 7170 (two shells) . Khao Pu Chao Bureau of Monks, Na Yong District, Trang (7°33’53.0”N 99°46’36.2”E): CUMZ 7171 ( fig. 8C ; 18 shells) and CUMZ 7172 (four shells). Wat Khao Huai Haeng, Huai Yot District, Trang (7°47’36.5”N 99°38’37.0”E): CUMZ 7173 (16 specimens in ethanol) . Wat Tham Sumano, Srinagarindra District, Phatthalung (7°35’14.0”N 99°52’06.8”E): CUMZ 7174 (10 specimens in ethanol) and CUMZ 7175 ( fig. 8A ; four shells and 33 specimens in ethanol). Khao Ok Talu Khuha Sawan, Mueang District, Phatthalung (7°37’33.7”N 100°05’23.7”E): CUMZ 7176 (three shells) and CUMZ 7177 ( fig. 8B ; 55 shells and 18 specimens in ethanol). Wat Khuha Sawan, Mueang District, Phatthalung (7°37’15.0”N 100°04’48.7”E): CUMZ 7178 (one shell) . Tham Phaya Hong, Kong Ra District, Phatthalung (7°27’48.4”N 99°57’53.3”E): CUMZ 7179 (36 shells) and CUMZ 7180 (22 shells and 137 specimens in ethanol) . Limestone outcrops at Khlong Chaloem, Kong Ra District, Phatthalung (7°23’50.6”N 99°58’45.2”E): CUMZ 7181 (five shells and 31 specimens in ethanol) . Tham Phra Non, Mueang District, Phatthalung (7°40’52.1”N 100°03’42.4”E): CUMZ 7182 (10 shells) .

Figure 9 Genitalia and spermatophore. A–C. Taphrenalla diadema specimen CUMZ 7180. A. whole reproductive system, B, internal wall of penis with penial verge. C. spermatophore; inset showing two spines located close to sperm sac. D–F. T. dalli sp. nov. paratype CUMZ 7184. D. whole reproductive system; inset showing a small penial caecum. E. internal wall of penis with penial verge. F. spermatophore of T. dalli sp. nov. specimen CUMZ 7186; inset showing two spines located close to the sperm sac.

Remarks. Taphrenalla diadema had been recently re-described and illustrated by Sutcharit & Panha (2008). The distinguishing characters are a depressed conic shell, medium-sized (width up to 17.8 mm; height up to 10.6 mm), a wide and deep channel-shaped suture, and short radial grooves appeared on last about 24–43 grooves (n = 39; figs 5, 8A–C). The genitalia have a short and straight epiphallic caecum, and dart apparatus located on vagina away from vagina and penis junction (figs 9A, B). Spermatophore has one short spine on tail filament close to sperm sac (fig. 9C). Living snail has yellowish stripes on head and tail ( fig. 3 ).

The specimens from Khao Ok Talu, Phatthalung Province ( fig. 8B ) tended to have a smaller diameter and shallower radial grooves than the other populations ( figs 8A, C ). However, all the genital characters and spermatophores from all localities appear to be identical. In addition, the molecular data also confirmed that the shell variations were all grouped within the T. diadema clade.

Figures

Figure 1 Map showing the sampling sites of the 11 Taphrenalla species along Southern Thailand.Each colour of the distribution range follows the phylogenetic tree of all Taphrenalla species in fig.3.

Figure 2 Representative ML tree of the Taphrenalla gen.nov., Macrochlamys, Sarika, Cryptozona, Hemiplecta, Megaustenia, and Durgella based on the combined partial sequences of the COI, 16S, and 28S genes. The code in the parenthesis next to the species name refers to voucher numbers of the analysed samples.Numbers on the branches indicate the ML BS and BI PP values.

Figure 3 A representative ML tree showing only the Taphrenalla clade.The synopsis of the radial groove on shell sculpture, genitalia showing location of dart apparatus, and live specimens of Taphrenalla spp. Results of species delimitation analyses based on the COI gene using ABGD and PTP.Black circles represent nodes with both ML (when Ē 70%) and BI (when Ē 0.95) support.White circles represent nodes with ML BS support but no BI PP support (when <0.95). Each clade colour refers to the distribution range in fig. 1.

Figure 8 Shells.A–C.Taphrenalla diadema. A.specimen CUMZ 7175.B. specimen CUMZ 7177.C.specimen CUMZ 7171 showing channel-shaped suture with wide bottom.D, E.T.dalli sp. nov. D. holotype CUMZ 7183.E. specimen CUMZ 7189 showing channel-shaped suture with very wide bottom. Inset SEM image showing shell sculpture of each species.