Seven new species ofAmynthas(Clitellata: Megascolecidae) and new earthworm records from Taiwan

Abstract

Earthworm specimens collected in southern Taiwan consisted of seven new species of Amynthas and several previously known species, mostly widely distributed peregrines. The new species are A. nanrenensis of the octothecal A. corticis species group, A. monsoonus and A. huangi of the sexthecal A. aelianus species group, and four proandric octothecal species: A. chaishanensis, A. hengchunensis, A. kaopingensis and A. ailiaoensis. Amynthas chaishanensis has dorsal intrasegmental spermathecal pores, but the other three proandric species have dorsal, lateral or ventral intersegmental spermathecal pores, respectively. The proandric species are united by several features, including the enclosure of segment xi in a sac, as in A. formosae (also proandric), octothecal with spermathecae in vi-ix, spermathecal diverticula stalks generally kinked and often enclosed in membrane, and prostatic ducts divided polytomously into numerous small ductlets, which may be grouped into bundles of two to five. In A. ailiaoensis the prostatic duct trunk contains up to seven separate lumens in the ental half, surrounded by the circular muscle of the duct, while in A. chaishanensis the prostatic duct trunk contains about 40 small lumens. Of the previously known species in the collection, Pontodrilus litoralis and Metaphire houlleti are first reported from Taiwan. Additional locations for A. incongruus and A. robustus are given, and in the latter case the material appears to be the usual male-sterile morph. Other species found are Pontoscolex corethrurus, Amynthas corticis, A. gracilis, Metaphire californica, and Polypheretima elongata.

Four new species ofAmynthasearthworms (Oligochaeta: Megascolecidae) from the Central Mountain Range of southern Taiwan

“…These characters are consistent among the A. biorbis individuals and distinctly different from the variable papillae arrangements in the preclitellar and male pore regions of A. corticis (Table 3). Gates (1959) and James et al (2005) reported A. corticis (= A. diffringens) specimens from Pingtung, southern Taiwan with fully developed reproductive organs showing no signs of male sterility (Table 3). Nevertheless, these authors are not quite sure whether their specimens are indeed the so-called A. corticis or a form closely related to A. corticis.…”

“…In the last decade, earthworm research in Taiwan has made rapid progress and 10 new species and two new records have been added to southern Taiwan's earthworm fauna. They are Metaphire puyuma from Taitung County (Tsai et al 1999), Metaphire glareosa from Taitung and Metaphire paiwanna paiwanna from Pingtung , Metaphire yeni from Pingtung , Metaphire feijani from Pingtung (Chang and Chen 2004), Metaphire tahanmonta from Pingtung and Kaohsiung (Chang and Chen 2005), Amynthas nanrenensis and Metaphire paiwanna hengchunensis from Pingtung (James et al 2005), Amynthas cruxus and Amynthas shinanmontis from Kaohsiung (Tsai et al 2007 (Perrier, 1872) from Pingtung (James et al 2005;Shen et al 2005) and Pontodrilus litoralis (Grube, 1855) from Pingtung and Kaohsiung (James et al 2005). Amynthas shinanmontis is distributed at elevations of 1850-2700 m (Tsai et al 2007), M. tahanmonta at elevations of 500-2500 m (Chang and Chen 2005), A. cruxus at elevations of 900-1700 m (Tsai et al 2007) and M. yeni and M. feijani at elevations more or less around 1000 m Chang and Chen 2004).…”

Some new Korean Megascolecoid earthworms (Oligochaeta)

“…Also the species has hooded male pores unlike other Korean species. Hooded male pores occur in some Philippine Amynthas (Hong and James 2004) and in some species from Taiwan (James et al 2005). However, the condition may have arisen independently in these two locations because other characteristics of the species in question are very different.…”

“…nov. keys out to the rimosus-group in Sims and Easton (1972), which is composed of A. rimosus effeminatus (Gates, 1932) and A. rimosus rimosus (Gates, 1931), both of which are from Myanmar. Amynthas formosae (Michaelsen, 1922) and A. chaishanensis (James et al, 2005) are proandric species from Taiwan, with dorsal intrasegmental pores on VI-IX (James et al 2005), but this new species has ventral intrasegmental spermathecal pores. Until now, only A. monstriferus (Kobayashi, 1936) recorded from Korea has ventral intrasegmental spermathecal pores, but A. monstriferus has manicate intestinal caeca.…”

“…Also the hoods themselves are of a different appearance. The species with hoods were A. philippinensis Hong et James, 2004, A. mindoroensis Hong et James, 2004, A. halconensis Hong et James, 2004 James et al, 2005, A. hengchungensis James et al, 2005 from Taiwan. Only A. philippinensis has one pair of spermathecal pores.…”