Biapertura sibirica Sinev 2020, comb. nov.

• Main Author: Sinev, Artem Y.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2020
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Branchiopoda; Diplostraca; Chydoridae; Biapertura; Biapertura sibirica; Churapcha; Sakha; Yakutia
• Online Access: https://zenodo.org/record/4331307; https://doi.org/10.5281/zenodo.4331307

Biapertura sibirica (Sinev, Karabanov & Kotov, 2020) comb. nov. Lilljeborg 1901: 459, Pl. 17: fig 12 (Alona affinis partum); Werestschagin 1911: 555 (Alona affinis var. dentata); Behning 1941: 315 (Alona affinis var. dentata); Smirnov 1971: 472–474, Fig. 590 (Alona affinis dentata); Sinev 1997: 53, Fig. 4C (Alona affinis var. dentata); Garibian et al. 2019: 49–52, Fig. 8 (Alona cf. affinis); Sinev et al. 2020: Fig. 1–5, 6 A–F (Alona). Type locality. Lake near road between Amga river and Churapcha, Sakha (Yakutia) Autonomous Republic, Russia, 61.80453° N, 133.2409° E. Type material: holotype (parthenogenetic female), allotype (adult male) and paratypes in Zoological Museum of M. V. Lomonosov Moscow State University, access numbers Ml–186, Ml–187 and Ml–188, respectively. Material studied earlier. See Sinev 1997 (A. affinis var. dentata) and Sinev et al. 2020 for the list of material from Eurasia, and for detailed description. Diagnosis. Female. Length of adult 0.68–0.94 mm. Body oval (Fig. 17A), maximum height at the middle of the body; height/length ratio about 0.6 in adults. Postero-dorsal angle with 1–3 denticles and few setulae (Fig. 17 B–D). Main head pores (Fig. 17E) with PP 1.5-2.3 in adults. Lateral head pores located about 0.9-1.3 IP distance from midline, at level before anterior major head pore. Postabdomen (Fig. 17F) subrectangular, with parallel margins, weakly narrowing at the end. Length about 2.5 height. Ventral margin straight. Dorsal margin weakly convex to straight in postanal portion and weakly concave in anal one, with distal part about 2.5 times longer than preanal one, with postanal portion 2.5–2.8 times longer than anal one. Postanal margin (Fig. 17G) with 11–13 massive denticles, each with 2–6 spinulae along anterior margin; size of denticles increasing distally. Postabdominal claw (Fig. 17H) with basal spine about 0.35 length of the claw. Antenna (Fig. 17I) with basal segment of both branches longer than two others, middle segments in both branches shorter than apical segments. Spine ...