(Vejdovsky, 1884a)
Description
Transparent worms. No eyes. Dorsal bundles beginning from VI, with 2-6 hair setae, 135-180 µm long, together with 2-6 crotchets, 72-85 µm long, finer and straighter than ventral crotchets, with short equal teeth. Ventral chaetae 5-10 per bundle, 69-88 µm long, with slightly longer upper tooth, similar in anterior and posterior parts of body. In mature individuals hooked, single-pointed penial chaetae by 1-3. Length 3-10 mm, segment number in zooids 11-27, in single individuals 14-53.
Crawling on substratum.
Distribution
Holarctic, China, Japan.
Ecology
In freshwater.
Reproduction
Mostly asexual, by paratomy (budding). Mature individuals and sexual reproduction rare or seasonal.
Literature
Vejdovsky, 1884a: 218; Sperber, 1939: 3-5, Fig. 2; Sperber, 1948: 95-98, Figs 9, 26D, Pl. IV, V Fig. 1; Sperber, 1950: 58, Fig. 7; Brinkhurst and Jamieson, 1971: 324-325, Fig. 7.3H-J; Chekanovskaya, 1981: 238-239, Fig. 107; Hrabe, 1981: 55, Pl. 8 Fig. 20-21; Kasprzak, 1981: 131, Figs 391-395.