(Piguet, 1906a)
Description
Small transparent worms, pinkish when alive. No proboscis, no eyes. Dorsal bundles begin from II, consisting of 1-2 finely serrated hair chaetae, 118-270 µm long, and 1-2 slightly curved needle chaetae, 39-96 µm long, with markedly shorter upper tooth. In ventral bundles 2-5 chaetae, 35-60 µm long, with longer upper tooth in forebody but with equal teeth rearward. Intestinal dilatation in VII or VIII. Transversal blood vessels free in IV-VIII but merged in plexus in I-III. Length 4-5.5 mm, segment number in zooids 16-18, in single individuals 21. Serration of hair chaetae, as well as the peculiar arrangement of anterior blood vessels distinguish Pristinella rosea from the other species with similar needle chaetae: Pristinella amphibiotica, Pristinella jenkinae and Pristinella menoni.
Crawling on substratum.
Distribution
Palaearctic, but recorded also from the Antilles.
Ecology
In freshwater.
Reproduction
Mostly asexual, by paratomy (budding). Mature individuals and sexual reproduction rare or seasonal.
Literature
Piguet, 1906a: 223-225, Pl. IX Figs 22-23; Sperber, 1948: 209-213, Fig. 22A; Sperber, 1950: 74, Fig. 26A; Brinkhurst and Jamieson, 1971: 392, Fig. 7.22L-M; Chekanovskaya, 1981: 271-272, Fig. 130; Hrabe, 1981: 60-61, Pl. 9 Fig. 20; Kasprzak, 1981: 103, Fig. 244-246.