Paramecium aurelia; Print; Paramecium aurelia are unicellular organisms belonging to the genus Paramecium of the phylum Ciliophora. They are covered in cilia which help in movement and feeding.Paramecium can reproduce sexually; asexually; or by the process of endomixis. Paramecium aurelia demonstrate a strong "sex reaction" whereby groups of individuals will cluster together; and emerge in conjugant pairs. This pairing can last up to 12 hours; during which the micronucleus of each organism will be exchanged. In Paramecium aurelia; a cryptic species complex was discovered by observation. Since then; some have tried to decode this complex using genetic data.