(Piguet, 1906a)
Description
Medium-sized smooth yellowish-pink worms. In dorsal bundles of anterior end usually 6-8 thin hair chaetae, 100-250 µm long, and 6-9 bifid crotchets, 74-105 µm long. In anterior ventral bundles 8-17 crotchets, 66-86 µm long. All crotchets with shorter upper tooth; their distal part immediately under teeth often reveals lateral, wing-like dilatations, similar to the head of an irritated cobra. Rearward, the number of chaetae decreasing without any change in their shape. No modified genital chaetae. Male pores in VII, clitellum in 1/2 VI-VIII. Posterior end modified as unsegmented tube, without chaetae, acting as gill. Length 14-40 mm, segment number up to 95-150 (but less in recently fragmented individuals). Highly numerous chaeta, arranged in fan-like bundles, are characteristic of Aulodrilus pluriseta. Lateral dilatations of crotchets in Aulodrilus pluriseta should not be confused with oar-like distal portion of dorsal chaetae in Aulodrilus pigueti, dilated in sagittal direction. There are no transversal rows of intermediate teeth in crotchets of Aulodrilus pluriseta, differently from Aulodrilus japonicus. The latter character can be seen only at high magnification and can thus remain unnoticed in some specimens identified otherwise as Aulodrilus pluriseta.
Burrowing in sediment; young individuals tossing about when irritated, in pure water.
Distribution
Holarctic incl. North Africa; Sino-Indian Region; Australia.
Ecology
In freshwater. Can build tube-like mud cases above mud surface, containing gill-like hind end.
Reproduction
Mostly asexual, by architomy (fragmentation). Mature individuals and sexual reproduction seldom observed and this mainly at low temperatures. Eggs laid in roundish cocoons with very tough brown, nontransparent shell and short unequal appendages.
Literature
Piguet, 1906a: 218-219; Brinkhurst and Jamieson, 1971: 525-526, Fig. 8.23J-N; Chekanovskaya, 1981: 282-283, Fig. 135; Hrabe, 1981: 68-69, Pl. 11 Figs 11-15; Kasprzak, 1981: 181, Figs 719-723.