Taphrenalla conformis Pholyotha & Panha, 2021

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 : 61-63

Taphrenalla conformis Pholyotha & Panha , sp. nov.

( figs 1 , 3 , 10C, 12A–C, table 6)

Type material examined. Holotype: CUMZ 7202 (fig. 10C). Paratypes. Same data as holotype: CUMZ 7203 (15 shells and 52 specimens in ethanol) , CUMZ 7230 (three specimens in ethanol) , CUMZ 7204 (eight specimens in ethanol) , CUMZ 7205 (11 shells and six specimens in ethanol) , CUMZ 7206 (24 specimens in ethanol) , NHMUK (two shells) , and SMF (two shells) .

Type locality. Tham Phung Chang, Mueang District, Phang-nga, Thailand (8°26’33.0”N, 98°30’55.4”E) .

Etymology. The specific name is from the Latin ‘ conformis ’ meaning “like” or “similar” and name refers to the new species possessing a superficially similar shell to T. parversa sp. nov.

Figure 12 Genitalia and spermatophore. A–C. Taphrenalla conformis sp. nov. paratype CUMZ 7230. A. whole reproductive system; inset showing a small penial caecum. B. internal wall of penis with penial verge. C. spermatophore; inset showing two spines located close to thesperm sac. D–F. T. incilis sp. nov. paratype CUMZ 7208. D. whole reproductive system. E. internal wall of penis with penial verge. F. spermatophore; inset showing two spines located close to the sperm sac.

Diagnosis. Shell having shallowly impressed suture, weakly radial grooves. Penis covered with thick penial sheath. Epiphallic caecum short and bent at tip. Penial caecum short. Inner sculpture of proximal penis with very small longitudinal folds; distally narrow and obliquely cuboidal folds. Dart apparatus connected on vagina. Spermatophore with two spines on tail filament close to sperm sac.

Description

Shell (fig. 10C). Shell comparatively depressed conic, medium-sized (width up to 17.7 mm; height up to 10.3 mm) and pale brown. Whorls 5–6; suture shallowly impressed. Upper shell surface with numerous weak radial grooves continuing from suture to gradually disappear before periphery. Spire depressed conic; apex raised with a spire angle of about 138–148°. Last whorl well-rounded periphery. Aperture lip simple; umbilicus narrowly opened.

Genital organs (figs 12A–C). Atrium slightly prolonged. Penis cylindrical and nearly three times total vagina length; penial caecum present. Inner sculpture of proximal penis with small longitudinal folds; distal portion with narrow obliquely cuboidal pilasters, then reduced in size and surrounding penial verge. Epiphallus slender tube, around two times total penis length and smaller diameter than penis. Epiphallic caecum short and bent at the tip; thick penial retractor muscle connecting near the tip. Flagellum short, tapering and irregular slender tube. Vas deferens thin tube. Vagina long and cylindrical-shaped. Dart apparatus located near proximal vagina away from penis join to atrium. Spermatophore long and needle-shaped. Tail filament very long tube; region close to sperm sac bearing two spines; spine close to sperm sac small and shorter than the other.

External features ( fig. 3 ). Animal dark gray in body colour with three pale milky yellow stripes running from head to caudal horn. One stripe at middle of the body and other two stripes above foot sole.

Remarks. Shell characters in T. conformis sp. nov. and T. parversa sp. nov. are very similar. They have a weakly impressed suture and weakly radial grooves on shell sculpture. However, the body colouration and reproductive organ can be used to separate them. In T. conformis sp. nov., the body has three pale milky-yellow bands running from the head to caudal horn, and the genitalia have a penial caecum. Whereas, the body colouration of T. parversa sp. nov. contains three bright orange stripes running from head to body, and only bright orange stripes on the body to tail. The genitalia of T. parversa sp. nov. do not have a penial caecum.

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 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.