Rhynchelmis limosella

Hoffmeister, 1843

Description
Large bluish red worms. Prostomium small, bearing short thin proboscis. Chaetae uniform in all segments, sigmoid, with simple blunt tip, with nodulus, 150-320 µm long. Male pores in X, spermathecal pores in VIII. Clitellum in VIII-XVI, long tubular atria with male pores in X, reaching internally several segments backwards. One pair of spermathecae in VIII, connected entally with oesophagus. Testes in IX and X. Unpaired, additional rudimentary atrium in IX, with pore in 8/9 or IX. Length 80-140 mm, body diameter 2-3 mm, segment number 160-200. The biggest lumbriculid species in NWE. Differing from another common congener, Rhynchelmis tetratheca, in its particularly robust but always simple-pointed chaeta. Other lumbriculids with proboscis and simple chaetae (Guestphalinus wiardi, etc.) are considerably smaller and have a different position of genital pores when mature.
Burrowing in sediment. Able to swim short distance when irritated.

Distribution
Western Palaearctic.

Ecology
In freshwater, not avoiding warm and muddy, vegetation-rich habitats.

Reproduction
Sexual only. Eggs laid in cocoons attached to substratum with one end.

Literature
Hoffmeister, 1843: 183, Taf. 9, Fig. 8; Grube, 1844: 204; Vejdovsky, 1876b: 332-361, Pl. 21-24; Cook, 1971a: 258-259, Fig. 5.9A; Chekanovskaya, 1981: 459-460, Figs 36, 235; Hrabe, 1981: 113-114; Kasprzak, 1981: 190-191, Figs 753-754.

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