(Michaelsen, 1901a)
Description
Medium-sized smooth pink worms. Prostomium short conical, separated by a distinct furrow from I, in alcohol-preserved specimens. Body wall delicate, with deep intersegmental furrows on tail when preserved. Anterior dorsal bundles with 1-5 hair chaetae, 300-650 µm long, and 3-5 pectinates, 80-175 µm long, with slightly longer upper tooth and short intermediate teeth. Anterior ventral chaetae by 3-6 per bundle, 120-165 µm long, with upper tooth slightly longer and thinner. Spermathecal chaetae 175-256 µm long. Male pores in XI, accompanied with a few ordinary crotchets. Length 15-45 mm, segment number up to 75. Differing from most congeners in the shape of spermathecal chaetae, but from Potamothrix vejdovskyi and Potamothrix moldaviensis, in the shape of dorsal chaetae. Young individuals are virtually indistinguishable from those of Potamothrix heuscheri, Potamothrix bavaricus, Potamothrix bedoti and Ilyodrilus templetoni; however, Tubifex tubifex has usually thinner body, weaker intersegmental furrows and more curved crotchets on its tail portion, while its prostomium is usually not so distinctly separated from I by a furrow as in Potamothrix hammoniensis and its congeners.
Burrowing in sediment.
Distribution
Western Palaearctic, Africa, Great Lakes of North America, Lake Titicaca in South America.
Ecology
In freshwater, common, particularly in the profundal of eutrophic lakes; sometimes also in brackish water.
Reproduction
Sexual only. Eggs laid in oval cocoons with brownish shell and two short appendages..
Literature
Michaelsen, 1901a: 66-68; De Visart, 1901: 1-3; Ditlevsen, 1904: 417-419, Pl. XVI Figs 15-17, Pl. XVIII Fig. 11; Brinkhurst and Jamieson, 1971: 491-492, Figs 8.11J, 8.12A-B; Chekanovskaya, 1981: 322-323, Fig. 156; Hrabe, 1981: 78-79, Pl. 12 Figs 9-14, Pl. 13 Fig. 4; Kasprzak, 1981: 157, Figs 533-537; Holmquist, 1985: 332, Figs 16, 22C, 23F, 24J.