Morphology of some species of the genus Aulodrilus Bretscher

The external and internal morphology of Aulodrilus limnobius Bretscher, 1899, Aulodrilus pluriseta (Piguet, 1906) and Aulodrilus japonicus Yamaguchi, 1953, and morphology of the setal apparatus of Aulodrilus pigueti were studied on new material from Russia and compared with various literature data. Besides the peculiar wings on bifid setae, dominance of asexual reproduction is regarded as a primary synapomorphy of the genus and is accompanied by an anterior shift of the whole reproductive system and a tendency to doubling the gonads. Naidid-like cocoons, with a single egg, are another element of this reproductive mode. Similar characters seem to have arisen independently in several groups of Oligochaeta.