Michaelsen, 1916
Description
Small white worms. Prostomium with short tentacle. Chaetae mostly 3 (seldom 4) per bundle as bifid crotchets, with slightly shorter upper tooth, 42-55 µm long. Two large glands attached to the back side of each chaetal bundle, inside body. Clitellum in 1/2 XII-XIV, male pores at its anterior edge. Spermathecal pores ventrally in the anterior half of IV. Length 6-12 mm, segment number 42-48. Considering chaetae, can be confused with some small tubificids, but easily distinguishable from them on the ground of tentacle and a different position of reproductive system.
Crawling in interstitial crevices, attaching to rough sand grains with sticky hind end.
Distribution
Palaearctic.
Ecology
In freshwater, particularly on sand bottom of large rivers.
Reproduction
Sexual, with eggs laid in cocoons.
Literature
Michaelsen, 1916: 51-55; Chekanovskaya, 1981: 372-373, Fig. 188; Kasprzak, 1986: 87-88, Figs 147-151; Coates, 1986: 423-425, Figs 1, 2b, 3.