In this study, eight species of Epistylis were observed attached to the cuticular surface of 13 body parts of crayfish Cambarellus patzcuarensis. The species found were E. bimarginata, E. branchiophila, E. carinogammari, E. gammari, E. lacustris, E. niagarae, E. stammeri, and E. variabilis. Some morphological structures of the species observed with optical and scanning electron microscopy are presented. The distribution of each species over the exoskeleton, as well as the occurrence, was recorded for each decapod studied. Specific richness and G tests were calculated for all body parts. Epistylis gammari was the most widespread species on the surface of C. patzcuarensis, being attached to the 13 body parts studied. Seven body parts harboured eight species while the gills supported only one species. Epistylid species did not show any preference for a particular body region but rather utilized the substrate available, and every body part plays an important role as a substrate; this is consistent with the value obtained from the G test. Epistylid species are already considered as epibionts without host or body region specificity.