Dichogaster (Diplothecodrilus) saliens ( Beddard, 1893 )

Wang, Yu-Hsi & Shih, Hsi-Te, 2010, Earthworm fauna of Eastern Taiwan, with descriptions of two new species (Oligochaeta: Megascolecidae), Zootaxa 2341, pp. 52-68 : 58

Dichogaster (Diplothecodrilus) saliens ( Beddard, 1893)

( Fig. 4 )

Microdrilus saliens Beddard 1893: 683 .

Dichogaster saliens— Gates 1935: 93; 1938: 220; 1958: 620; 1972: 281; Michaelsen 1900: 343; Stephenson, 1931a: 65; 1931b: 199; Csuzdi 1995: 114; Shen 2007: 72–73, fig. 1; Tsai et al. 2009: 37.

Material examined. 4 adults, NCHUZOOL 13501, 23°57’52.9”N, 121°29’57.2”E, 150 m, Tongmen, Sioulin, Hualien Co., Taiwan, coll. Y.-H. Wang et al., 1 Jan. 2005.

Diagnosis. Dimensions 27–36 mm by 1.4–1.6 mm in x. Segments, 100–118. Setae distributed in ventral; 2 setae a pair; 4 pairs in ventral. Prostomium, epilobic ( Fig. 4 b); segments without secondary annulation. First dorsal pore at 5/6, spermathecal pore 2 pairs, mid-ventral at 7/8–8/9. Female pore not visible. A genital marking mid-ventral at 15/16, with a pore. Male pores on mid-xvii, coin-shaped; without setae between male pores; without penial setae. Clitellum, xiii–xx or xiii–xx 1/2 ( Fig. 4 a). Spermathecae paired. Ampulla with diverticulum in viii and ix ( Fig. 4 c). Prostates, longitudinal in xvi–xviii ( Fig. 4 d). Gizzards large in vii–viii and ix–x.

Remarks. The specimens in our study are small in size, although the clitellum is developed. Dichogaster saliens ( Beddard, 1893) is close to D. affinis (Michaelsen, 1890) , D. annae (Horst, 1893) , and D. bolaui (Michaelsen, 1891) ( Table 2), but they can be separated by the genital marking and the shape of the male pores. According to Michaelsen (1900) and Sims & Gerard (1985), the male pores of D. bolaui are stripshaped on xviii without genital marking. Stephenson (1931a) reported the male pores of D. annae are on xvii– xix without genital marking. Shen & Tsai (2007) reported D. saliens from Changhua Co. in west-central Taiwan with the following characters: the diamond-shaped male pores are on xvii with genital marking between 15 and 16. Shen et al. (2008a) reported D. affinis from Yunlin Co. in west-central Taiwan with the following characters: the bracket-shaped male pores are on xviii with genital markings at the middle of 7/8-9/ 10 ( Table 2). The specimens collected from eastern Taiwan were identified as D. saliens , but there is a pore within the genital marking between 15 and 16. Specimens were collected from wet soil near the roots of reeds.

Figures

FIGURE 4. Dichogaster (Diplothecodrilus) saliens; a, ventral view of spermathecal pores and coin-like male pores; b, dorsal view of prostomium (epilobic); c, right spermathecae; d, right prostate. amp, ampulla; dv, diverticulum; fp, female pore; gm, genital marking; sp, spermathecal pore. All scale bars are 0.5 mm.