The presence of larvae and pupae of the genus Metrichia (Trichoptera, Hydroptilidae), larvae of the genus Macrelmis and Phanocerus (Coleoptera, Elmidae), three diatom genera Achnanthes, Cocconeis, Gomphonema, and some specimens of very small diatoms that could not be determined to species or genus level, were recorded for the first time as epibionts for Chordodes brasiliensis (Gordiida, Nematomorpha). Such epibionts were found on the body surface of this species of hairworms, captured from El Tala stream, Catamarca, Argentina.Facultad de Ciencias Naturales y Museo