(Cernosvitov, 1937a)
Description
Small transparent worms. No proboscis, no eyes. Dorsal bundles beginning from II, consisting of 1-2 serrated hair chaetae, 80-200 µm long, and 1-2 needle chaetae, 36-40 µm long, with equally short diverging teeth. In ventral bundles 4-7 bifid chaetae anteriorly, 2-4 posteriorly; they are 36-44 µm long, the longest in the middle segments of forebody. Their upper tooth is longer than lower one in II-III, becoming gradually equal and then shorter in the subsequent segments. Stomach beginning abruptly from VIII. Length 1.5-2.5 mm, segment number in the first zooid 26(?), in the entire worm 28. Fine serration of hair chaetae (visible only under high magnification) and the larger segment number distinguish this species from Pristinella osborni.
Crawling on substratum.
Distribution
Known mostly from South America, but also from Europe and Africa.
Ecology
In freshwater, rare.
Reproduction
Mostly asexual, by paratomy (budding). Mature individuals and sexual reproduction rare or seasonal.
Literature
Cernosvitov, 1937a: 140-141, Figs 13-16; Sperber, 1948: 223; Brinkhurst and Jamieson, 1971:396.