(Verrill in Smith and Verrill, 1871)
Description
Large red worms with unpigmented anterior end. Prostomium truncated, cone-shaped. External secondary annulation weakly expressed. Chaetae two per bundle, sigmoid with distal nodulus, single-pointed, about 180 µm long. Unpaired spermathecal pore in IX (sometimes another also in VIII), unpaired male pore in X. Clitellum in 1/2 VIII-1/2 XIV. Pharyngeal glands extend from IV to VI. Chloragogen tissue on digestive tube begins from VI. Large, simple blind lateral blood vessels, one pair per segment, covered with dark chloragogen cells, from XVI to XXI or XXII; two pairs of blind lateral vessels per segment more caudad, bearing numerous small appendages penetrating body wall. Testes in IX and X, ovaries in XI. Single tubular atrium in X with very thick muscular wall covered with prostatic cells; penis small, protrusible. Single median spermatheca in IX (occasionally another in VIII) with pear-shaped ampulla and long discrete duct. Length 35-50 mm, diameter 0.8-1.4 mm, segment number not known. Differs from the other European lumbriculid with unpaired genital pores, Tatriella slovenica, first of all in the atrium completely covered with prostatic tissue, but also in the complicated system of blood vessels.
Burrowing in sediment. Able to swim.
Distribution
Western Europe, North America.
Ecology
In freshwater, mainly in lakes.
Reproduction
Sexual only. Eggs laid in irregularly cylindrical cocoons with two tuft-like appendages.
Literature
Smith and Verrill, 1871: 449; Smith, 1919: 84-88; Cook, 1967: 361-362, Fig. 6; Cook, 1971a: 250-251, Figs 5.7B, 5.8A-D; Kasprzak, 1981: 192, Figs 744, 760-763; Brinkhurst, 1998: 652-653, Fig. 5.