(Giani and Martinez-Ansemil, 1981)
Description
Locomotory chaetae as bifid crotchets with shorter upper tooth, by 2-5 in anterior bundles and by 2-3 in posterior bundles, about 30 µm long. Penial chaetae with simple hooked tip and extremely distal nodulus, thicker and straighter than locomotory chaetae, 33-36 µm long, 4 per bundle. No coelomocytes. Length about 3 mm, segment number known as 29. Differing externally from the other small species with similar locomotory chaetae, in the shape of penial chaetae: they are mostly bifid in Gianius aquaedulcis and not thicker than the locomotory chaetae in Spiridion phreaticola; in Rhyacodrilus balmensis penial chaetae are proximally dilated and hollow, while coelomocytes occur in body cavity.
Burrowing in sediment.
Distribution
Europe.
Ecology
In freshwater, rare.
Reproduction
Sexual only. Eggs laid in cocoons.
Literature
Giani and Martinez-Ansemil, 1981: 201-205, Fig. 1.