Hrabe, 1963
Type genus Rhyacodrilus Bretscher, 1901
Number of species about 135. In fresh waters of NWE, 7 genera with 15 species:
Bothrioneurum vejdovskyanum Stolc, 1886
Branchiura sowerbyi Beddard, 1892
Epirodrilus pygmaeus (Hrabe, 1935)
Monopylephorus irroratus (Verrill, 1873)
Monopylephorus limosus (Hatai, 1898)
Pararhyacodrilus ekmani (Piguet, 1928)
Pararhyacodrilus palustris (Ditlevsen, 1904)
Peristodrilus montanus (Hrabe, 1962)
Rhyacodrilus amphigenus Juget, 1987
Rhyacodrilus ardierae Lafont and Juget, 1993
Rhyacodrilus balmensis Juget, 1959
Rhyacodrilus carsticus Kosel, 1980
Rhyacodrilus coccineus (Vejdovsky, 1876a)
Rhyacodrilus falciformis Bretscher, 1901
Rhyacodrilus subterraneus Hrabe, 1963
Description
Large, medium or small tubificids, with smooth body. Chaetae as bifid crotchets in most species, sometimes also simple-pointed crotchets; hair and pectinate bundles can occur in dorsal bundles. Modified genital chaetae (usually penial chaetae, often with distal tips close to each other; seldom also spermathecal chaetae) often occur in corresponding ventral bundles. Differing from the other subfamilies first of all in the structure of male duct: atrium is covered with diffuse prostate tissue. Sperm in spermathecae is amorphous, or arranged in loose bundles, and spermathecal pores lie in anterior portion of X. Coelomocytes present in body cavity. A paraphyletic taxon in the cladistic sense, as it includes ancestors of the other tubificid subfamilies and the Naididae.
Burrowing in sediment.
Distribution
Cosmopolitan.
Ecology
In fresh, brackish and marine water.
Reproduction
Mostly sexual, with eggs laid in cocoons. In some separate genera and species also asexual reproduction by architomy (fragmentation).
Literature
Stolc, 1886: 640; Stolc, 1888: 42; Hrabe, 1963: 54; Hrabe, 1966: 70; Hrabe, 1981: 62; Brinkhurst and Jamieson, 1971: 445; Kasprzak, 1981: 140.