(Stephenson, 1931)
Description
Small transparent worms. No proboscis, no eyes. In dorsal bundles, beginning from II, 1-2 smooth hair chaetae, 108-200 µm long, and 1-2 needle chaetae, 29-65 µm long, being usually the longest in IV. Needle chaetae variable but mostly with upper tooth slightly shorter than lower one. In ventral bundles anteriorly 3-7, posteriorly 2-3 chaetae, 32-55 µm long. Ventral chaetae with teeth of about equal length in all bundles. In some mature specimens, single modified genital (spermathecal) chaetae observed in VII; clitellum in 1/2VII-IX. Intestinal dilatation gradual, in 1/2 VI-1/2 VII or VII. Length 2.5-4 mm, segment number in the first zooid 11-13, in the entire worm 14-19. The related species Pristinella amphibiotica and Pristinella menoni differ from Pristinella jenkinae in that they reveal a gradual change in ventral chaetae (the upper tooth becoming shorter) rearward.
Crawling on substratum.
Distribution
Cosmopolitan.
Ecology
In freshwater.
Reproduction
Mostly asexual, by paratomy (budding). Mature individuals and sexual reproduction rare or seasonal.
Literature
Stephenson, 1931: 39-41, Fig. 1; Sperber, 1948: 220-222, 224-225, Figs 23D-F, Pl. XX, XXI Fig. 1; Sperber, 1950: 76, Fig. 27D-F; Brinkhurst and Jamieson, 1971: 394-355, 396-397, Figs 7.22I-K, 7.23A-B; Kasprzak, 1981: 99-100, Figs 221-228.