Camaena poyuensis Zhou, Wang & Ding

Ding, Hong-Li, Wang, Pei, Qian, Zhou-Xing, Lin, Jun-Hong, Zhou, Wei-Chuan, Hwang, Chung-Chi & Ai, Hong-Mu, 2016, Revision of sinistral land snails of the genus Camaena (Stylommatophora, Camaenidae) from China based on morphological and molecular data, with description of a new species from Guangxi, China, ZooKeys 584, pp. 25-48 : 34-35

Taxon classification Animalia Stylommatophora Camaenidae

Camaena poyuensis Zhou, Wang & Ding sp. n. Figs 4E, 5, Table 4

Material examined.

Holotype. FJIQBC 18484, specimen preserved in ethanol, China, Guangxi Zhuang Autonomous Region, Hechi City, Bama County, Poyue town, 24°17'30"N; 107°05'32"E (Fig. 1); limestone mountain, coll. WC Zhou, May 25, 2014.

Paratypes. 19 specimens with the same data as holotype but with the following specimen codes: 4 in ethanol (FJIQBC 18485-18488), 2 adults; 15 empty shells (FJIQBC 18489-18503), 9 adults.

Measurements of shells see Table 4.

Diagnosis.

Shell sinistral, large, thick, discoidal, with obtuse apex and low dome-shaped spire; 5 1/2 rapidly increasing and slightly convex whorls separated by deep suture; body whorl expanded; peripheral angle blunt. Surface with thick growth lines, and fine spiral ribs. Aperture lunate, angulated by peripheral carina. Peristome expanded, reflected, thickened and glossy. Inner lip thin, forming a smooth, semi-translucent, and purplish callus. Basal lip and columellar lip straight, with obtuse angle at junction. Umbilicus covered completely by reflected columellar lip. Color pattern of several wavy, reddish brown spiral bands of various thickness, peripheral and subsutural bands much wider; spire dark brown. Peristome and callus tinted purplish (Fig. 5A), fading to red-dotted pink on dead-collected shells (Fig. 5B).

Animal light brown, tentacles dark brown, distinct yellowish line, running from the head between tentacles to the collar near the peristome (Fig. 5C). Penis swollen, tapering distally, with a rounded bulge in correspondence of verge. Epiphallus thick, with short, thin and wide penis retractor muscle. Flagellum slender, tapering distally. Vas deferens long and thin. Vagina long and thin, thickened proximally. Bursa copulatrix head oval with long and thin pedunculus, expanded at base. Verge short, conic, with six longitudinal grooves extending from verge base to about three quarters of its length and narrowly-spaced transverse wrinkles. Inner penial wall supporting several pilasters: proximally transverse, weak and dense surrounding verge, distally longitudinal, prominent and widely-spaced (Fig. 4E).

Etymology.

For the type locality, adjective of feminine gender.

Distribution.

This species is known from the type locality only.

Ecology.

The new species habits in a well-preserved subtropical evergreen broadleaved forest, and is not common. The animal was not found in farmland adjacent to the forest.

Comparative remarks.

Diagnostic comparisons of morphological characters of the new species and the other four Camaena were summarized in Table 5. The new species and Camaena cicatricosa are sister taxa (Fig. 2) and similar in shell shape, color pattern and absence of a hump beside umbilicus. The shell of Camaena cicatricosa differs from the new species by having a smaller shell, higher spire, a half opened umbilicus, a more dilated columellar lip, peristome white, curved basal lips. Among the sinistral species of the subgenus Camaena (Camaena) , only Camaena obtecta (Fischer, 1898) and the new species have a totally covered umbilicus and, hence, can be distinguished from the others. Camaena obtecta shows thick umbilical callus, a hump beside the margin of the callus, white peristome, and a thicker shell and a higher spire than the new species.

The morphology of the reproductive system of Camaena poyuensis is similar to Camaena cicatricosa , but differs in the following characters: The pedunculus of the bursa copulatrix is longer, more than twice as long as the vagina (it is about as long as the vagina in Camaena cicatricosa ). The epiphallus and penis are thicker than in Camaena cicatricosa , and the penis has a visible projection. Camaena poyuensis sp. n. has shorter verge with both transverse and longitudinal grooves, and transverse pilasters in proximal part of penis. The verge of Camaena obtecta is similar to that of Camaena poyuensis sp. n. in shape, but its surface is covered throughout with irregular, fine and curly wrinkles. Only transverse pilasters are present in the penis of Camaena obtecta , whereas both the transverse and longitudinal pilasters are seen in the new species.