Morphological differences between genetic lineages of the peregrine earthworm : Aporrectodea caliginosa (Savigny, 1826)

Aporrectodea caliginosa is a universally distributed and highly abundant peregrine earthworm that is the object of many ecological and ecotoxicological studies. Molecular phylogenetic analysis suggested that A. caliginosa consists of three highly diverged genetic lineages. In this study, we investigated morphological diversity within a sample of these three lineages from Belarus. We detected a variety of forms with different degrees of pigmentation and a shift in the clitellum position. The three genetic lineages of A. caliginosa demonstrated different propensity to particular morphological variants, including size, colour, and the clitellum position, yet no character could be used to distinguish among the lineages with sufficient accuracy. Thus, our results suggest that identification of the genetic lineage should be recommended for ecological studies involving A. caliginosa to account for possible differences between them.