Abstract
A new species, the third one from Vietnam, of the genus Aporcelinus is described from natural areas. Aporcelinus falci-caudatus sp. n. is characterized by its 1.28 to 1.63 mm long body, lip region offset by weak constriction and 16 to 18 μm broad, odontostyle 18 to 21 μm at its ventral side, neck 354 to 406 μm long, uterus tripartite and 61 to 95 μm long, V = 50 to 55, tail strongly recurved dorsad and conical (23–31 μm, c = 43–58, c’ = 0.7–0.9) with finely rounded tip, and male absent. Scanning electron microscope (SEM) study, the first of a representative of the genus, shows a lip region pattern significantly different from that observed in the typical aporcelaimid taxa.