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

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.