Two new species of Metacyclops Kiefer, 1927 (Copepoda, Cyclopoida) from Thailand and an up-to-date key to the species recorded in Asia

Metacyclops sakaeratensis sp. nov. and M. brancelji are described as being present in the mountainous areas of Northeastern Southern Thailand, respectively. Two new species resemble woni both sexes, but they easily distinguished from their Cambodian relative by having: 1) transverse suture on dorsal surface genital double-somite, 2) serrated hyaline frill posterior margin third pedigerous somite, 3) different length / width ratio caudal ramus, 4) a row spinule intercoxal sclerite swimming legs. The significant differences between including body size, integumental ornamentation surface, armature fifth leg, male sixth leg. In addition, an up-to-date key to female all fifteen recorded Asia is provided.