Amynthas bouchei Zhao and Qiu, 2009

Zhao, Qi, Sun, Jing & Qiu, Jiang-Ping, 2009, Three new species of the Amynthas hawayanus-group (Oligochaeta: Megascolecidae) from Hainan Island, China, Journal of Natural History 43 (17 - 18), pp. 1027-1041 : 1028-1031

Amynthas bouchei Zhao and Qiu sp. nov

( Figure 2 )

Type material

Holotype: Clitellate specimen (C-HN005): 225 mm long, 7 mm wide, 212 segments. Setae numbers: 54/III, 80/ V, 90/VIII, 90/XX, 88/XXV; 34( VI), 35( VII) between spermathecal pores, 17( XVIII) between male pores; collected at the end of a road

covered by leaves in Jianfengling National Nature Reserve, Southwest Hainan, 18 ° 439260 N, 108 ° 539560 E, at an altitude of 900 m ( Figure 1 ). Collected by Jianxiong Li and Weixin Zhang .

Paratype: one clitellate (C-HN005): collected under the arbores near the road in the forest in Wufen District of Jianfeng Mountain , Hainan. 18 ° 449080 N, 108 ° 529070 E, at an altitude of 850 m by Weixin Zhang and Jiangping Qiu .

Other material

Some data as for holotype, one aclitellate specimen.

Etymology

The species is named after Professor M.B. Bouche, who is a famous oligochaetist. He has contributed greatly to the taxonomy of earthworms and participated in the fieldwork in Hainan .

Diagnosis

Spermathecal pores three pairs, ventral, in 5/6–7/8, about 0.4 body circumference apart. No genital papillae in this region. Male pores a little less than 0.33 body circumference apart, ventrally placed, each on top of a conical porophore, surrounded by three to five skin folds. Two large oval genital papillae to the inner side of the male pores anterosetal and posterosetal.

Description

Worms with no pigment dorsally before clitellum and ventrally; light olive brown dorsally after clitellum. Lutescens on clitellum. Dimensions 225–286 mm by 7– 7.8 mm; segments 212–237. Setae intensive, regularly distributed around segmental equators, their numbers: 54–64 at III, 80–86 at V, 84–90 at VIII, 90 at XX, 79–88 at XXV; 34–40(VI), 35–39(VII) between spermathecal pores, 17–18(XVIII) between male pores; setal formula AA51–1.6AB, ZZ51.3–2ZY. Female pore single in the centre of XIV ventrally, ovoid, brown. First dorsal pore in 12/13. Prostomium onefifth epilobous. Clitellum in 3/4 XIV–XVI, ring-shaped, markedly glandular; ventral setae (12/XVI), dorsal pore and annulus visible.

Male pores paired in XVIII a little less than 0.33 body circumference apart, ventrally placed, each on top of a conical porophore (diameter 1.8–2.2 mm), surrounded by three to five skin folds. Two large oval genital papillae on the inner side of the male pores anterosetal and posterosetal. Spermathecal pores three pairs, ventral, in intersegmental furrows of 5/6–7/8, each eye-shaped and obvious, distance between paired pores about 0.4 body circumferences apart. No genital markings in this region.

Septa 8/9, 9/10 absent; 5/6–7/8, 10/11 and 11/12 comparatively thick and musclar; 12/13, 13/14 a little thicker than those following. Gizzard ball-shaped, in IX–X. Intestine starting enlarged in XV. Intestinal caeca simple, originating in XXVII, extending anteriorly to XXIV, dark brown, with distinct dorsal tooth-shaped diverticula, smooth ventrally. Oesophageal hearts four pairs, in X–XIII.

Spermathecae three pairs, in VI –VIII; ampulla elongated ovoid, duct stout, about two-thirds of ampulla, diverticula a little longer than main pouch and coiled, ental one-half dilated, serving as seminal chamber (holotype in C-HN005), or diverticula a little shorter than main pouch nearly straight, the ental one-third enlarged, serving as seminal chamber (paratype in C-HN005). Testis sacs paired in X and XI, those in X elongate reaching to dorso-median, those in XI enclosing the first pair of seminal vesicles. Seminal vesicles paired in XI and XII, stout. Prostate gland in XVII–XIX, small, coarsely lobed and divided into three main lobes, with a short S-shaped duct, its ectal limb stouter .

Remarks

Amynthas species with three pairs of spermathecal pores in 5/6–7/8 have been reported from China and Southeast Asia ( Thai 1982; Chen 1938; Hong 2001, 2007; Tsai et al. 2001, 2007; Shen et al. 2002, 2003). They include the following Hainan species: Amynthas brevicingulus , Amynthas limpidus and Amynthas muticus . However, the male characters of A. muticus and A. limpidus are very unlike A. bouchei sp. nov.

The new species is similar to A. brevicingulus ( Chen 1938) in having three pairs of spermathecal pores in 5/6–7/8 and simple intestinal caeca, but it has two large oval glandular papillae on the inner side of the male pores anterosetal and posterosetal while A. brevicingulus has two large elongate papillae generally placed on ventral side of XVII, postsetal and medial to male porophores. What is more, the range interval between spermathecal pores of A. bouchei sp. nov is about two-fifth body circumference apart compared with one-eighth body circumference of A. brevicingulus . Amynthas bouchei sp. nov. with body length 225–286 mm is much larger than A. brevicingulus . The two species also differ in the position of the first dorsal pore: 12/ 13 in A. bouchei sp. nov versus 11/ 12 in A. brevicingulus . The comparison with other Amynthas species with spermathecal pores in 5/6–7/8 from China is shown in Table 1.

Figures

Figure 1. Collection sites in Hainan Island: species 1, Amynthas bouchei sp.nov. (species 1 was collected in Jianfengling National Nature Reserve); species 2, Amynthas omodeoi sp. nov.; species 3, Amynthas edwardsi sp. nov. (both species 2 and species 3 were collected in Diaoluoshan National Forest Park).

Figure 2. Amythas bouchei sp. nov. (A) ventral view. (B) spermathecae; scale bars 3.5 mm (A), 0.9 mm (B).