Three new species of earthworms in the Amynthas (Clitellata: Megascolecidae) from Nam Xam National Protected Area, Laos

Earthworm specimens collected from the Nam Xam National Protected Area, Laos, belong to three new species of megascolecid earthworms: Amynthas xamtaiensis sp. nov., Amynthas vanhyai sp. nov., and Amynthas multipapillatus sp. nov. The authors provide a new record for Amynthas gracilis (Kinberg, 1867). All three new species key to the gracilis (hawayanus) group in Sims and Easton (1972), defined by having three pairs of spermathecal pores in 5/6–7/8. A. xamtaiensis sp. nov. has male pores superficial in thickened areas, containing two genital papillae medial to the male pores. A. vanhyai sp. nov. has male pores equatorial oval pads at sixth setal lines, and shallowly pinnate intestinal ceca having 6–10 lobes on each edge. A. multipapillatus sp. nov. has male pores on small longitudinal shallow invaginations at lateral margins of the ventrum, and more than 100 small genital papillae covering the ventral surface from 16/17 to 17/18.