Brinkhurst in Brinkhurst and Jamieson, 1971
Type genus Phallodrilus Pierantoni, 1903
Number of species about 300. In fresh waters of NWE, two genera with three species:
Gianius aquaedulcis (Hrabe, 1960)
Gianius riparius (Giani and Martinez-Ansemil, 1981)
Spiridion phreaticola (Juget, 1987)
Description
Medium or small tubificids, with smooth body. Chaetae usually as bifid crotchets with upper tooth shorter and thinner than lower one; no hair or pectinate chaetae. Modified genital chaetae, usually penial chaetae, often occur in X. Differing from the other subfamilies primarily in the structure of male duct: atrium is equipped with two compact, stalked prostate glands attached to its proximal and distal end. Sperm in spermathecae is amorphous, or arranged in loose bundles, and spermathecal pores lie in anterior portion of X. Coelomocytes absent.
Burrowing in sediment.
Distribution
Cosmopolitan.
Ecology
Mostly marine; several species have invaded fresh (particularly subterranean) waters independently.
Reproduction
Sexual, with eggs laid in cocoons.
Literature
Pierantoni, 1903: 114; Brinkhurst and Jamieson, 1971: 564; Kasprzak, 1981: 181; Finogenova, 1986: 198-199; Erséus, 1992: 5-48.