Chydorus izvekovae Sinev & Novichkova & Chertoprud 2022, sp. nov.

• Published in: Quaternaire
• Main Authors: Sinev, Artem Y., Novichkova, Anna A., Chertoprud, Elena S.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2022
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Branchiopoda; Diplostraca; Chydoridae; Chydorus; Chydorus izvekovae; Magadan; Thermokarst
• Online Access: https://zenodo.org/record/6647233; https://doi.org/10.5281/zenodo.6647233

Chydorus izvekovae sp. nov. Figs. 1-6 Type locality. A small thermokarst lake near Yanskiy village, Olsky District, Magadan Area, Russia (N59°45.994' E149°29.622'), samples were collected on 10.07.2014 and 06.07.2015 by A.A. Novichkova. Type material. Holotype. A parthenogenetic female from the type locality, deposited in the Zoological Museum of M. V. Lomonosov Moscow State University, Ml 251. Paratypes. 30 parthenogenetic females from the type locality, deposited in the Zoological Museum of M. V. Lomonosov Moscow State University, Ml 252; 47 parthenogenetic females from lake near Yanskiy village, Olsky District, Magadan Area, Russia, N59°46.659' E149°29.4416'), 10.07.2014 and 06.07.2015, coll. A.A. Novichkova; 6 parthenogenetic females from small lake in vicinity of Klyopka village, Olsky District, Magadan Area, Russia (N59°47.9015' E151°24.7691'), 10.07.2015, coll. A.A. Novichkova. Etymology: the species is named after our late teacher, colleague and friend, prominent Russian chironomidologist Evelina Ivanovna Izvekova (1939-2021). Description. Parthenogenetic female. Body shape typical of the genus Chydorus, oval in juveniles (Fig. 1A) and rounded in adults (Figs. 1B, 2A–D) in lateral view, height/length ratio about 0.9, maximum height at midline. In frontal and posterior view (Figs. 2E–F), body subtriangular, with weakly convex dorsal surface and moderately developed egg locules, significantly narrowing in ventral half. Valves and head shield covered everywhere by numerous honeycomb-like meshes, not organized into ridges or collars (Figs. 2–4). Height of mesh walls low, about 10 µm in highest meshes. Surface of valves inside the meshes oblique or with irregular lines. Valves. Anterior corner broadly rounded, with a submarginal flange at inner side. Ventral margin of valves (Fig. 1C) with about 50–55 setae; 10–12 anterior setae very thin, short, located on the inner side of valves close to margin, followed by about ten very short setae located maginally. Posterior group consists of over 30 long setae, armed ...