Mazepovacandona orbiculata (Mazepova, 1990)

Karanovic, Ivana & Sitnikova, Tatiana Ya., 2017, Morphological and molecular diversity of Lake Baikal candonid ostracods, with description of a new genus, ZooKeys 684, pp. 19-56 : 26-28

Mazepovacandona orbiculata (Mazepova, 1990) Figs 8, 9, 14E, 15E

Candona orbiculata sp. n. - Mazepova (1990): p. 95, fig. 30

Material examined.

One male soft body used for DNA extraction and after that dissected and mounted on one glass slide (shell on SEM stub), three juveniles kept in 95% alcohol, all collected from 12-15 m depth by SCUBA diving off Listvyanka, 51°51'51.3"N, 104°50'37.8"E, 12 September 2015, collectors: Igor Khanaev and Ivan Nebesnykh.

Short redescription.

Valves reniform in lateral view, with almost evenly rounded dorsal margin (Fig. 8A, B). Anterior and posterior margins broadly rounded, posterior wider than anterior. Ventral margin almost straight, with bulging around mouth region. Surface smooth and covered with pores, all equipped with semi operculum (Fig. 8C, D). Length around 0.6 mm.

A1 lost during DNA extraction. Male A2 with subdivided penultimate segment and t2- and t3-setae transformed into sexual bristles; z1-seta transformed into claw, z2-setae not observed, z3-seta untransformed; G1- and G3-claws reduced and short, G2-claw long (Fig. 9A). Prehensile palps (Fig. 9B, C) with body and fingers equally long, fingers curved, hook-like. L6 (Fig. 9D) with basal seta reaching far beyond basal segment. L7 (Fig. 9E) not clearly 5-segmented, penultimate segment partially subdivided; basal segment with d1- and dp-setae; no e- or f-setae, g-seta long; terminal segment with setae h2- and h3- long and h1-seta shorter, but also considerably long. UR (Fig. 9G) robust, with long posterior seta and strong claws. Hemipenis always (?) in semi-erectile mode (Fig. 9F, 14E); a-lobe relatively small but its shape hard to accurately perceive due to its folded position; M-peace rounded distally, ejaculatory tube with pointed distal end. Zenker organ (Fig. 15E) with 4+2 whorls of spines; anterior cap hemispherical, with strongly sclerified margin, lattice elaborate, on anterior side adjoined by longer spines. Eyes large and dark.