Claparède, 1862
Type species Stylodrilus heringianus Claparède, 1862
Number of species 28. Five species known from NWE:
Stylodrilus absoloni (Hrabe, 1970)
Stylodrilus brachystylus Hrabe, 1929a
Stylodrilus heringianus Claparède, 1862
Stylodrilus lemani (Grube, 1879)
Stylodrilus parvus (Hrabe and Cernosvitov, 1927)
Description
Medium or small lumbriculids. Prostomium without proboscis. External secondary annulation usually well developed. Chaetae two per bundle, sigmoid with nodulus, either simple-pointed or with small parallel upper tooth. Testes in IX and X, ovaries in XI, spermathecae in IX; spermathecal pores in IX, single pair of male pores in X, respectively. Penes present or absent. Posterior lateral blood vessels revealing different number and shape in different species. Differing from most other lumbriculid genera in having one pair of atria in X, and one pair of spermathecae in preatrial segment of IX. Two separate, closely related genera, Stylodrilus (with bifid chaetae) and Bythonomus (with simple-pointed chaetae) have often been recognized among this assemblage.
Burrowing in sediment.
Distribution
Holarctic, including Lake Baikal.
Ecology
In freshwater.
Reproduction
Sexual only. Eggs laid in cocoons.
Literature
Claparède, 1862: 221; Grube, 1879: 116; Grube, 1880: 228; Vejdovsky, 1884a: 226; Hrabe and Cernosvitov, 1927: 203; Brinkhurst, 1965: 431-434; Cook, 1968: 281-282; Cook, 1971a: 239-240; Chekanovskaya, 1981: 443-444, 451-452; Hrabe, 1970: 283-284; Hrabe, 1981: 99, 102; Kasprzak, 1981: 192-193, 195-196.