Amynthas ailiaoensis, James & Shih & Chang, 2005

James, Samuel W., Shih, Hsi-Te & Chang, Hsueh-Wen, 2005, Seven new species of Amynthas (Clitellata: Megascolecidae) and new earthworm records from Taiwan, Journal of Natural History 39 (14), pp. 1007-1028 : 1020-1021

Amynthas ailiaoensis sp. nov.

( Figure 3C–E )

Holotype: adult collected at Wutai , Pingtung County, Taiwan, 24 August 1998 by Chung- Chi Huang, NMNS 4054-020 . Paratypes: four adults, collected at Wutai , Pingtung County, Taiwan, 24 August 1998 by Chung-Chi Huang, NMNS 4054-021 .

Etymology

This species is named after the Ailiao River, of the locality Wutai.

Description

Dimensions 215–310 mm by 9–12.5 mm at segment x, 9–10 mm at xxx, 8–12 mm at clitellum; body cylindrical throughout, segments 110–140. Setae regularly distributed around segmental equators, numbering 86–96 at vii, 90–94 at x, 126–140 at xxv; size uniform; setal formula AA:AB:YZ:ZZ51:1:1:2.5 at xxv. Female pore single in xiv. Prostomium epilobic, with tongue open. Brown pigment on dorsal third, intensity variable; first dorsal pore 12/13. Clitellum annular xiv–xvi; setae invisible externally.

Male pores within shallow circular invagination of body wall, in each of which one oblong longitudinally orientated genital marking is folded in half transversely; 20 setae between male pores, pores 0.26 circumference apart on setal line 15. Spermathecal pores mid-lateral to slightly ventral of mid-lateral 5/6/7/8/9 ( Figure 3C ).

Septa 5/6/7/8 muscular, 8/9/10 absent, 10/11–13/14 muscular; gizzard viii; oesophageal wall with low lamellae xii–xiii. Intestinal origin 1/2xv; 42–50 longitudinal intestinal blood vessels; typhlosole simple fold from 27/28, 1/8 lumen diameter. Intestinal caeca simple, margins smooth, xxvii–xxiii; lymph glands from xv; blood glands in v. Oesophageal hearts x–xiii, commissural vessels vii, ix lateral, viii to gizzard; supraoesophageal vessel xi–xiii; extraoesophageal vessels join ventral oesophageal wall in x; posterior latero-parietal vessels from body wall of xiv–xvi, septum 13/14 to ventral oesophageal location of extraoesophageal vessels in xiii.

Male sexual system proandric, testes, funnels in ventrally joined sac in x. Seminal vesicles large in xi, with large dorsal lobes; seminal vesicles, other contents of xi sometimes enclosed in thin sac. Prostates large in xviii, seven main lobes, each lobe served by two to three small ductlets radiating fan-like from ental end of prostatic duct ( Figure 3D ); ducts stout, muscular, narrowing towards body wall; vasa deferentia join duct at duct–glandular portion junction; vasa deferentia non-muscular.

Ovaries in xiii. Paired spermathecae vi–ix; ampulla pear-shaped, duct much shorter than ampulla, diverticulum with small ovate chamber, stalk slender, tightly convoluted in hairpin loops enclosed in membrane ( Figure 3E ); no nephridia on spermathecal ducts.

Remarks

The fourth octothecal proandric Amynthas of Taiwan is much more similar to Gates’ (1959) material from Chao-Chow (5Chaojhou), Pingtung and Green Mountain (5Yangmingshan), Taipei than the others. Differences from Gates’ material are few. It is possible that these are the same species. A. ailiaoensis has paired genital markings within a shallow invagination of the male field, lacks septum 8/9, has much shorter caeca, and the spermathecal pores are at or above mid-lateral rather than ‘‘well towards mL’’ which might mean below mid-lateral but close. Many small nematodes were found in the body cavity, mainly around the caeca, prostates and seminal vesicles.

Figures

Figure 3. (A) Left lateral view of segments i–ix and ventral view of Amynthas kaopingensis, with detail of male pore; (B) spermatheca of Amynthas kaopingensis; (C) dorsal view of segments i–x and ventral view of xiv–xix of Amynthas ailiaoensis; (D) left prostate gland of Amynthas ailiaoensis, showing numerous small ductlets (curved line traversing the gland is septum 17/18); (E) spermatheca of Amynthas ailiaoensis; (F) dorsal view of segments i–x and ventral view of xiii–xix, Amynthas chaishanensis (the dashed line on the dorsal view represents the mid-dorsal line); (G) spermatheca of Amynthas chaishanensis.