(Knöllner, 1935)
Description
Small white worms. Chaetae by 2-7, most numerous in the tail region, 27-45 µm long, sigmoid, simple-pointed, with ectal nodulus, missing in XII. Male pores in XII; clitellum in 1/2 XI-1/2 XIII, with glands arranged in transversal rows. Interior characters: Pharyngeal glands in two pairs; dorsal lobes at 4/5 and 5/6 connected with each other, ventral lobes in V and VI. Coelomocytes elongated, spindle-shaped or occasionally oval, granulate. No appendages on digestive tube. Blood colourless or faintly yellow, dorsal vessel reaches backwards 13/14. Spermathecae in V, not connected with oesophagus, with distinct narrow ectal duct, and with slightly longer but much broader cylindrical ampulla; no glands on spermathecal pore. Ampulla contains spermatozoa arranged in rings only in its distal end; ental portion is usually thick-walled, with narrow lumen. Male funnels cylindrical, length twice as large as width, with collar of the same width. Vas deferens short, slightly dilating at ectal end; no atrium; small glands surrounding male pore. Unpaired anterior seminal vesicle (sperm sac) present, reaching up to VIII. Eggs in XII only. Length 5-7 mm, segment number 26-28. Can be distinguished from congeners only on the basis of internal anatomy. Anterior seminal vesicle distinguishes Cernosvitoviella immota from all its congeners.
Burrowing in sediment. Behaviour very sluggish, with infrequent quick jerks.
Distribution
Europe, eastern shore of North America.
Ecology
In wet soil, on shores of fresh and slightly brackish water bodies.
Reproduction
Sexual, with eggs laid in cocoons.
Literature
Knöllner, 1935: 438-443, Figs 9-13; Nielsen and Christensen, 1959: 40-41, Figs 19-22; Kasprzak, 1986: 113-114, Figs 225, 271-276.