Oxyurella Dybowski & Grochowski, 1894

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 : 482-483

Oxyurella Dybowski & Grochowski, 1894

Parthenogenetic female short description. Body low oval ( Fig. 15 I), head and valves without a keel. Valves oblique. Posteroventral angle of valves without denticles. Rostrum short. Three main head pores ( Fig. 15 J) without a connection between them; lateral head pores minute. Labral keel wide, with a rounded apex, without clusters of setulae on posterior margin.

Postabdomen ( Fig. 15 K) elongated, narrowing distally in postanal portion, with protruding rounded distal angle; length about 3.5–4 height. Preanal and postanal angles weakly defined. Postanal denticles long and narrow, distalmost denticle significantly thicker and longer than others, its length over 2 widths the postabdominal claw base ( Fig. 15 L). Postanal lateral groups of setulae with distalmost seta longer than others; in distalmost groups, length of setulae less than width of postabdominal claw base; unlike in most Aloninae , distalmost group of setulae located at significant distance from the end of postabdomen. Postabdominal claw moderately long, almost straight, with long basal spine.

Antennule without lateral aesthetascs, all terminal aesthetascs of similar length. Antennal seta without basal peg. Antenna with thin seta on basal segment of endopodite. Spine on basal segment of exopodite of similar length than middle segment. Spines on apical segments longer than apical segments. IDL of limb I with three setae ( Fig. 15 M), seta 1 short, setae 2–3 thin, armed with thin setulae.

Single species, Oxyurella singalensis (Daday, 1898) ( Fig. 15 I–M). Length of adult 0.55–0.85 mm. Common species, found in lakes, ponds, reservoirs, slow rivers and paddy fields. Littoral species, associated with vegetation. Indo-Malaysian species. For description, see Idris (1983).

Figures

FIGURE 15. A – F, Notoalona globulosa globulosa (Daday, 1898). A, lateral view. B, head pores. C, labrum. D, postabdomen. E, antenna. F, IDL of limb I. G – H, Notoalona pseudomacronyx Van Damme, Maiphae & Sa-Adrit, 2013. G, lateral view, H, postabdomen. I – M, Oxyurella singalensis (Daday, 1898). I, lateral view. J, head pores. K, postabdomen. L, postanal margin of postabdomen. M, IDL and ODL of limb I. N – P, Salinalona sarasinorum (Stingelin, 1900). N, lateral view. O, postabdomen. P, IDL and ODL of limb I. (Orig.)