Cernosvitoviella microtheca

Rota and Healy, 1999

Description
Very small white worms. Chaetae by 3-7, most numerous in ventral bundles, sigmoid, simple-pointed, with nodulus, 16-27 µm long, absent from XII. Male pores in XII; clitellum in XII-1/2 XIII, rectangular clitellar glands arranged in transverse rows laterally, absent on dorsal and ventral sides. Interior characters: Pharyngeal glands in two pairs; dorsal lobes at 4/5 and 5/6 connected or not with each other, ventral lobes in V and VI. Coelomocytes of two kinds: spindle-shaped with or without fine points, with refractile granules; and roundish or oval, with yellow granules. Chloragogen tissue consisting of large cells, covering oesophagus from V. No appendages on digestive tube. Blood colourless; dorsal blood vessel reaching backward up to 11/12. Spermathecae in V, not connected with oesophagus. Spermathecae very small, with spherical ampulla only 10-20 µm in diameter, and thick-walled duct of equal length or slightly longer and slightly narrower than ampulla. Sperm in ampullae usually not arranged in a transversal ring. No glands at spermathecal pores. Male funnels funnel-shaped, without distinct collar. Vasa deferentia slightly dilatated in ectal third or half. Flat gland cells surrounding male pore. One single egg in clitellar region. Length about 1.3 mm, segment number 18-23.Can be distinguished from congeners only on the basis of internal anatomy; most closely related to Cernosvitoviella minor and Cernosvitoviella goodhui.
Burrowing in sediment.

Distribution
Sweden.

Ecology
In freshwater wetlands.

Reproduction
Sexual, with eggs laid in cocoons.

Literature
Rota and Healy, 1999: 32-34, Fig. 1A-C.

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