Leydigiopsis Sars, 1901

Sinev, Artem Y., 2016, Key for identification of Cladocera of the subfamily Aloninae (Anomopoda: Chydoridae) from South-East Asia, Zootaxa 4200 (4), pp. 451-486 : 477

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).

Figures

FIGURE 12. A – D. Kurzia longirostris (Daday, 1898) A, lateral view. B, head pores. C, labrum. D, postanal margin of postabdomen (lateral setulae not shown). E – F. Leydigia ciliata (Gauthier, 1939). E, lateral view. F, postabdomen. G – I. Leberis diaphanus (King, 1853). G, lateral view. H, postabdomen. I, IDL of limb I. J, Leberis punctatus (Daday, 1898) IDL and ODL of limb I. (Orig.).

FIGURE 13. A – B, Leydigiopsis pulchra Van Damme & Sinev, 2013. A, lateral view. B, postabdomen. C – G. Magnaspina siamensis (Sinev & Sanoamuang, 2007). C, lateral view. D, posteroventral corner of valves. E, head pores. F, postabdomen. G, IDL and ODL of limb I. H – K, Matralona freyi (Idris & Fernando, 1981). H, lateral view. I, labrum. J, postabdomen. K, IDL and ODL of limb I. (A – B—from Van Damme & Sinev (2013); C – G, from Sinev & Sanoamuang (2007), H – K, from Sinev & Kotov (2012 )).