Leydigiopsis Sars, 1901

Parthenogenetic female short description. Body high oval (Fig. 12A); head and valves without a keel. Valves without sculpture. Posteroventral angle of valves without denticles. Rostrum long, curved. Main head pore as elongated rimmed field, lateral head pores minute. Labral keel of moderate width, with a rounded apex, without clusters of setulae on posterior margin.

Postabdomen broad (Fig. 12B), with convex postanal margin, convex distal margin and broadly rounded distal angle; length about 2.3–2.6 heights. Preanal angle well-defined; postanal angle weakly defined. Postanal denticles large, numerous; length of distalmost denticles over 2 widths of postabdominal claw base. Postanal lateral groups of setulae of moderate length; in distalmost groups, length of setulae about the width of base of postabdominal claw. Postabdominal claw long, almost straight, with rudimentary basal spine.

Antennule with three lateral aesthetascs; all terminal aesthetascs of similar length. Antennal seta arising from well-defined tubercule. Antenna with a spine-like seta on basal segment of endopodite. Spine on basal segment of exopodite about 2/3 length of middle segment. Spines on apical segments of same lenght than apical segments. IDL of limb I with three setae; seta 1 short, seta 2–3 thin, armed with thin setulae.

Single species, Leydigiopsis pulchra Van Damme & Sinev, 2013 (Fig. 13A–B). Length of adult 0.65–0.75 mm. Inhabit forest peat swamps and humic ponds; bottom-dwelling species. Species is known from South Thailand, Cambodia, South Vietnam and India (Van Damme & Sinev, 2013). For detailed description see Van Damme & Sinev (2013).