First record of Conidophrys pilisuctor (Ciliophora : Pilisuctorida) as ectosymbiont of Hyalella azteca from Mexico

Abstract

The pilisuctorid ciliate Conidophrys pilisuctor is recorded for the first time as ectosymbiont of the freshwater amphipod Hyalella azteca collected in Patzcuaro Lake, Michoacan, Mexico. The morphometrical data of several phases of its life cycle ( except free tomites) and of its prevalence on the host's body regions are presented. The pilisuctorid was observed attached exclusively to the setae of various appendages from which those of the pereiopods and antennae had the greatest prevalences. However, the results of v 2 tests show that there was not a homogeneous ciliate preference for the body regions of H. azteca. From the cluster analysis, several regions presented a greater degree of similarity according to prevalence and presence - absence of the ciliate. Some aspects are considered for the establishment of symbiosis.