Amynthas apapillatus Zhao and Qiu, 2013

Zhao, Qi, Sun, Jing, Jiang, Jibao & Qiu, Jiangping, 2013, Four new species of genus Amynthas (Oligochaeta, Megascolecidae) from Hainan Island, China, Journal of Natural History (J. Nat. Hist.) 47 (33 - 34), pp. 2175-2192 : 2187-2191

Amynthas apapillatus Zhao and Qiu , sp. nov.

( Figure 4 )

Type material

Holotype: Clitellate specimen (C-HN201114-03Z): 120 mm long, 4 mm wide, 83 segments. Setae numbers: 36/III, 32/ V, 44/ VIII, 48/XX, 44/XXV; 12( V), 16( VI), 16( VII) between spermathecal pores, 12( XVIII) between male pores; collected in tropical rain forest of Quling Mountain in Limushan Nature Reserve, 19 ◦ 13 ′ 40 ′′ N, 109 ◦ 44 ′ 15 ′′ E, at an altitude of 739 m. Collected by J. P. Qiu, Q. Zhao, J. B. Jiang, D. Cluzeau and W. K. Zhang.

Etymology

The species is named after the absence of genital papillae around the male pore.

Diagnosis

Spermathecal pores three pairs, ventral, in 6/7–8/9, about 0.4 body circumference apart. No genital markings in this region. Male pores about 0.6 body circumference apart, ventrally placed, each on top of a round porophore. No genital papillae in this region.

Description

Preserved specimens brown dorsally and light brown ventrally. Dimensions 120 mm by 4 mm, 83 segments. Setae intensive, regularly distributed around segmental equators, their numbers: 36/III, 32/V, 44/VIII, 48/XX, 44/XXV; 12(V), 16(VI), 16(VII) between spermathecal pores, 12(XVIII) between male pores; setal formula AA = 1.2–1.3AB, ZZ = 1.2ZY. Female pore single in the ventral centre of XIV, ovoid, brown. First dorsal pore in 11/12. Prostomium epilobous. Clitellum in XIV– XVI, ring-shaped, light brown, markedly glandular; ventral setae invisible but dorsal pore visible.

Male pores paired in XVIII about 0.4 body circumference apart, ventrally placed, each on top of a round porophore. Genital papillae absent. Spermathecal pores three pairs in 6/7–8/9, ventral, each eye-shaped and obvious, distance between paired pores about 0.4 body circumference apart. Genital markings absent.

Septa 8/9, 9/10 absent; 5/6–7/8 comparatively thick and muscular; 10/11–11/12 thin. Gizzard ball-shaped, in IX–X. Intestine starting enlarged in XVI. Intestinal caeca simple, originating in XXV, extending anterior to XXVII, dark brown, with three distinct teeth-shaped diverticula dorsally, smooth ventrally. Oesophageal hearts four pairs, in X–XIII, the last three pairs developed.

Spermathecae three pairs, in VII–IX; ampulla elongated ovoid, duct stout, about 0.5 of ampulla, distinctly separated; diverticulum about 0.67 of main pouch and coiled, ental 0.25 enlarged, serving as the seminal chamber, silvery white in appearance inside the chamber. Testis-sacs paired in X and XI. Seminal vesicles paired in XI and XII, well-developed, both separate ventrally. Prostate gland in XVII–XVIII, small, coarsely lobated, with a stout U-shaped duct.

Remarks

Amynthas apapillatus sp. nov. keys to the sieboldi -group according to Sims and Easton (1972). Compared to the Amynthas species reported from China with three pairs of spermathecal pores in 6/7–8/9 ( Chen 1931, 1936, 1946; Tsai 1964; Chen et al. 1975; Zhong and Ma 1979; Zhong et al. 1984; Qiu 1992; Qiu et al. 1993; Wang and Qiu 2005; Tsai et al. 1999; Shen et al. 2003; Chang et al. 2009), Amynthas apapillatus is most similar to Amynthas pingi chungkingensis ( Chen, 1936) . They share some similar characters: three spermathecal pores, heart-shaped ampulla, short diverticulum and ovoid seminal chamber. But there are neither genital papillae nor genital markings, nor accessory gland in Amynthas apapillatus sp. nov. The prostate of Amynthas apapillatus sp. nov. is small while that of Amynthas pingi chungkingensis is well-developed. The distance between COI sequences of Amynthas apapillatus sp. nov. and the other four

0.02

Amynthas species is always>19%. Furthermore, the distances of combined COI and 16S sequences among these species are also>15% ( Figure 5 , Table 2). Sequences of COI and 16S genes of Amynthas apapillatus were deposited in GenBank under Accession No. JQ951519 and JQ951518 ( Table 1).

Figures

Figure 4. Amynthas apapillatus sp. nov.; (A) ventral body surface with spermathecal pores; (B) spermatheca; (C) ventral body surface with male pores; (D) intestinal caeca.

Figure 5. Neighbour joining (NJ) tree of Amynthas species; (A) based on COI sequences; (B) based on combined COI and 16S genes.