Ovalona Van Damme & Dumont, 2008

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

Ovalona Van Damme & Dumont, 2008

Parthenogenetic female short description. Body oval ( Fig. 14 F, J), of moderate height; head and valves without keel. Sculpture of valves as weak longitudinal lines or tubercules. Posteroventral angle of valves without denticles. Rostrum short. Three main head pores with a narrow connection between them or disconnected ( Fig. 14 G, K), lateral head pores minute. Labral keel of moderate width, with a rounded apex; in South-East Asian species without clusters of setulae on posterior margin.

Postabdomen moderately wide ( Fig. 14 H, L), with parallel margins in postanal portion, with protruding distal angle; length about 2.3–2.8 heights. Preanal angle well defined, postanal angle weakly defined. Postanal denticles short, not exceeding the width of postabdominal claw base. Postanal lateral groups of setulae with long and thick distalmost seta; in distalmost groups length of setulae 1.5 widths the base of postabdominal claw. Postabdominal claw short, curved, with short 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. 13 I); seta 1 short, setae 2–3 thin, armed with thin setulae.

Figures

FIGURE 14. A, Monospilus dispar Sars, 1862, lateral view. B – E. Nicsmirnovius eximius (Kiser, 1948). B, lateral view. C, head pores. D, postabdomen. E, IDL of limb I. F – I. Ovalona cambouei (Guerne & Richard, 1893). F, lateral view. G, head pores. H, postabdomen. I, IDL and ODL of limb I. J – L. Ovalona archeri (Sars, 1888). J, lateral view. K, head pores. L, postabdomen. (A – E, orig.; F – I, from Sinev (2015); J – L, from Sinev (2002 )).

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 )).