Jeju-do earthworms (Oligochaeta: Megadrilacea)-Quelpart Island revisited

Abstract

Surveys on Jeju-do (Quelpart Isl.) unearthed about 40 earthworm species or sub-species. Several considered new to science are described. Only a dozen were previously known and these are taxonomically reviewed. The two most commonly recorded in surveys by S. Kobayashi in the 1930s were Drawida anchingiana Chen, 1933 and Metaphire quelparta (Kobayashi, 1937), neither recently relocated. Morphologically similar taxa, supported with DNA barcodes, for Moniligastridae, are Drawida anchingiana seogwipo, D. anchingiana halla and D. iucn spp. or sub-spp. nov. For Megascolecidae, new taxa and synonyms are: Amynthas arx and A. aucklandis spp. nov. that have seminal grooves rather than the eversible male pores of Metaphire plus Amynthas simplex is another new species. Amynthas sangumburi Hong & Kim, 2002 is recognized as a probable new synonym within the A. corticis (Kinberg, 1867) species-group while Amynthas corticis saeseum sub-sp nov. is described. Amynthas gracilis (Kinberg, 1867) is a new record from Jeju and Korea (with A. bouchei, A. omodeoi and A. edwardsi all by Zhao & Qiu, 2009 possible synonyms of this species group from China) with a Jejuan sub-species, A. gracilis insularum, sub-sp. nov. Presence on Jeju of Amynthas carnosus (Goto & Hatai, 1899) is confirmed (its further new synonyms are Chinese A. fuscus Qiu & Sun, 2012 and A. taiwumontis Shen et al., 2013), as is A. micronarius (Goto & Hatai, 1898) (with new synonym A. montanus Qiu & Sun, 2012 also an invalid secondary homonym). Amynthas phaselus maculosus (Hatai, 1930) is in new combination with A. kamitai (Kobayashi, 1934) and A. minjae Hong, 2001 syns. nov. Two newly described Metaphire quelparta sub-spp are M. q. seogwipo and M. q. valhalla these being supported with DNA barcodes despite the nominal taxon not yet being confirmed.