Camptocercus streletskayae Smirnov 1998

Camptocercus streletskayae Smirnov, 1998 (Figs. 1–2) Smirnov, 1998: 70–71, figs 28–44, Pl. 2. Type locality. Lake Chaun, the vicinity of Magadan, Eastern Siberia, Russia. Type material. Holotype. Female at the Natural History Museum, London, United Kingdom, 1997.1753t. Paratypes. Females at the Natu...

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Bibliographic Details
Main Author: Sinev, Artem Y.
Format: Other/Unknown Material
Language:unknown
Published: 2015
Subjects:
Online Access:https://zenodo.org/record/6120024
https://doi.org/10.5281/zenodo.6120024
Description
Summary:Camptocercus streletskayae Smirnov, 1998 (Figs. 1–2) Smirnov, 1998: 70–71, figs 28–44, Pl. 2. Type locality. Lake Chaun, the vicinity of Magadan, Eastern Siberia, Russia. Type material. Holotype. Female at the Natural History Museum, London, United Kingdom, 1997.1753t. Paratypes. Females at the Natural History Museum, London, United Kingdom, 1997.1754 - 1761. Studied material: 2 specimens from the type locality; 3 parthenogenetic females from Russia, Chukotka, a puddle in the region of the Anadyr River, about 65 ° N, 171 ° E, coll. E.A. Streletskaya, AAK 1999 -048. Description. Parthenogenetic female. General. Body (Fig. 1 A) with a well-expressed dorsal keel, moderately high, slightly fusiform in lateral view (height/length ratio about 0.65 in adult), with maximum height anterior to middle of the body, strongly compressed laterally. Dorsal margin highly arched, without a depression between valves and headshield. Posterodorsal angle broadly rounded; posterior margin convex. Posteroventral angle broadly rounded. Ventral margin from almost straight to irregularly convex, with about 55–65 short ventral setae (Fig. 1 B–C). Row of ventral setae ends at about 3 / 4 length of ventral margin, followed by numerous very short setules, subdivided into unclear groups. Posteroventral angle (Fig. 1 D–F) with 2–4 small denticles; specimens could have a different number of denticles on left and right valve, according to Smirnov (1998), some specimens could lack denticles. Length of denticles about width of denticle base; distance between denticles about 2–4 widths of denticle base. Anteroventral angle rounded. Valves with prominent longitudinal lines, rarely anastomosing, according to SEM photos in Smirnov (1998), valves and headshield are covered by fine striae. Head (Fig. 1 G) with a sharp triangular rostrum, protruding downward. Head keel wide; distance from eye to the keel margin about 4 diameters of compound eye. Ocellus smaller than eye; distance from tip of rostrum to ocellus 1.5 times greater than distance between ...