Rudjakov, 1962
Diagnosis
This deep-living species is extremely fragile and most specimens are too damaged to observe the carapace shape. Dorsal margin is more or less straight with little development of the shoulder vaults (C. vitjazi Habitus 1, C. vitjazi Habitus 4). Postero-dorsal corner forms an angle of just over 90°, with a minute spine on the right valve. Posterior margin curves smoothly into the ventral margin. Maximum carapace height close to mid-length. Some specimens show a clear sculpturing of >-shaped striae over the whole of the carapace (C. vitjazi Habitus 3). The right asymmetrical gland opens on the tip of a small tubercle. Left asymmetrical gland also opens on a similar tubercle just anterior to the posterior end of the hinge.
Female, frontal organ undifferentiated, nearly three times the length of first antenna, basally straight, but curves sharply down before ending in a long point (C. vitjazi 1). First antenna, dorsal seta absent, "a"-d setae one and a half times the length of the limb, but only half the length of the "e" seta. Second antenna endopodite, the processus mamillaris small, "b" seta with tuft of long hairs at midpoint (C. vitjazi 3).
Male, previously undescribed, these characters based on an Atlantic specimen. Frontal organ stem equal in length to first antenna, capitulum bare, down-turned, with a broad base tapering to a nipple-like point on the end (C. vitjazi 4). First antenna, "a" seta convoluted, similar in length to second podomere, "c" seta short, "b", "d" and "e" setae are subequal, "e" seta armature 17 pairs of basally-pointing, slender spines (C. vitjazi 5). Second antenna endopodite with ; "a" and "b" setae subequal, "b" seta with tuft of long hairs (C. vitjazi 6), other setae were broken but r seta probably terminally flattened. Right-hand hook appendage basally angled through 90°, then curving through a decreasing arc through a further 90°, to end in a ridged rounded swelling.
Remarks
Another species which provides evidence for considerable faunistic uniformity in the abyssopelagic communities throughout the World's oceans.
Distribution
Recorded from the North Pacific and North Atlantic 20°N-49°N. Species probably widely distributed at abyssopelagic depths. 1 (R.R.S. Discovery Map).
Type specimens
Not recorded.
Type locality
Kuril-Kamchatka Trench in North Pacific.