Amphidromus (Syndromus) fuscolabris Möllendorff, 1898

Inkhavilay, Khamla, Sutcharit, Chirasak & Panha, Somsak, 2017, Taxonomic review of the tree snail genus Amphidromus Albers, 1850 (Pulmonata: Camaenidae) in Laos, with the description of two new species, European Journal of Taxonomy 330, pp. 1-40 : 32-34

publication ID	https://doi.org/ 10.5852/ejt.2017.330
DOI	https://doi.org/10.5281/zenodo.3848209
persistent identifier	https://treatment.plazi.org/id/03DAD35F-6939-EF29-FE30-A9E6FEA02644
treatment provided by	Carolina
scientific name	Amphidromus (Syndromus) fuscolabris Möllendorff, 1898
status

Treatment

Amphidromus (Syndromus) fuscolabris Möllendorff, 1898 View in CoL

Figs 1 View Fig , 9 View Fig E–F, 12G–I, 13J–M, 14C–D; Table 1 View Table 1

Amphidromus zebrinus fuscolabris Möllendorff, 1898: 75 View in CoL . Type locality: Boloven (Boloven Plateau, Paksong District, Champasak, Laos).

Amphidromus zebrinus fuscolabris View in CoL – Pilsbry 1900: 199–200. — Zilch 1953: 134, pl. 23, fig. 22. — Laidlaw & Solem 1961: 564, 621. — Richardson 1985: 49.

Material examined

Type material

LAOS: holotype SMF 7641 ( Fig. 13I View Fig ).

Other material

LAOS: 34 shells, typical form ( Fig. 13 View Fig J–K, CUMZ 7040); 2 specimens, in ethanol ( Figs 9E View Fig , 12 View Fig G–I, 14C−D, CUMZ 7041); 73 + 10 juveniles, yellowish form ( Fig. 13 View Fig L–M, CUMZ 7042); 2 specimens, in ethanol ( Fig. 9F View Fig , CUMZ 7043), Ban Phone, La-Marm District, Sekong; 2 shells, Ban Xai Na Pho, Phatumphone, Champasak ( CUMZ 7044).

Description

Shell sinistral, elongate conical, rather solid and glossy. Spire elongate conical; apex acute, with pinkish tint to brownish without black spot on tip. Whorls 6 to 7 nearly smooth; suture wide and shallow; last whorl rounded. Periostracum transparent to thin corneous, with greenish streaks on lower half of last whorl. Last whorl shows yellow to orange Band 1; Bands 2 to 5 merged and become six or seven black or brown slanted blotches; Band 6 yellow; varix absent. Parietal callus thickened, bright purplishpink. Aperture elongated auriform; peristome thickened, expanded and not reflected; lip purplish-pink. Columella rather thick, straight, dilated and purplish-pink. Umbilicus imperforated.

Radula

Each row contains about 161 (80-(35-31)-1-(31-35)-80) teeth. Central tooth unicuspid, with curved cusp. Lateral and marginal teeth similar to that described in A. areolatus . Marginal teeth start from lateral tooth 17 to 21 outwards ( Fig. 12 View Fig G−I).

Genital organs

Atrium (at) rather long (n = 10). Penis (p) long, cylindrical and slightly swollen at distal end. Epiphallus (e) short, half of penis length; flagellum (fl) of about same length as epiphallus and terminated with pointed tip. Appendix absent. Penial retractor muscle (pr) thin and long. Vas deferens (vd) very narrow tube connecting epiphallus and free oviduct ( Fig. 14C View Fig ).

Internal penial wall corrugated into strong penial pilasters, which form fringe around penial verge. Penial verge conical, with smooth surface and orifice open near tip ( Fig. 14D View Fig ).

Vagina cylindrical, long, slender, about two times as long as penis. Gametolytic duct long, proximal to genital orifice of a relatively larger diameter than vagina and distally tapering; distal to genital orifice small tube of about same length as proximal part and connected to gametolytic sac. Oviduct and albumin gland very small ( Fig. 14C View Fig ).

Internally, vaginal wall shows longitudinal vaginal pilasters (vp); proximal to genital orifice with thin wall and smooth surface, distally pilasters show continuous ridges ( Fig. 14D View Fig ).

Distribution

The original description of this species was given by Möllendorff (1898) and the type locality was Boloven, Laos. Unfortunately, we couldn’t obtain any specimen from the type locality in our recent survey. The specimens were collected from a mountain at Ban Phone (Phone village), Sekong Province, and Ban Xai Na Pho (Xai Na Pho village) Phatumphone, Champasak, Laos, which are both located at a lower altitude than the Boloven Plateau. It seems that this species is only found in low altitude habitats.

Remarks

Amphidromus fuscolabris differs from A. zebrinus and A. eudeli in having a large and elongate shell, apex tinted pink, purplish-pink parietal callus, Band 1 yellowish and Bands 2 to 5 merged and becoming 6 to 7 slanted blotches (on last whorl). In comparison, A. zebrinus (see Sutcharit et al. 2015: fig. 15k) has a smaller shell, Band 1 absent, Bands 2 and 5 merged and becoming fifteen narrow slanted stripes on last whorl, and reddish band in between Bands 5 and 6. On the other hand, A. eudeli ( Fig. 13N View Fig , holotype RBINS 617427) has a smaller shell, thin parietal callus, Bands 2 and 3 merged and Bands 4 and 5 well developed.

Two color forms were observed from Sekong, Laos. These are the typical form ( Fig. 13 View Fig I–K) and the yellowish form that is monochrome yellowish, with Bands 2 to 5 absent and stained with pale yellowish color, and Band 6 sometimes present as a brownish color ( Fig. 13 View Fig L–M). However, these two color forms show a pinkish to purplish-pink parietal callus and columella, and have identical genital structures and sculptures inside the penis and vagina. In addition, they occur sympatrically and so we recognize them as conspecific.