Abstract

Some naidid oligochaetes establish commensal relationships with species of molluscs worldwide. In the present study, we report the finding of Chaetogaster limnaei in Illapel River, northern Chile. This worm was found inhabiting the mantle cavity of the freshwater gastropod Physa acuta, an invasive species in this country. The taxonomic status of C. limnaei was confirmed by molecular analysis based on mitochondrial 16S ribosomal RNA gene.