A STUDY OF THE DISTRIBUTION AND ECOLOGY OF LITTORAL FRESH-WATER CHYDORID (CRUSTACEA, CLADOCERA) COMMUNITIES IN IRELAND USING MULTIVARIATE ANALYSES

The distribution and ecology of the littoral freshwater Chydoridae in Irish waterbodies were investigated. A total of 316 samples was taken at 287 substrate classified sampling sites throughout the Republic of Ireland, and representatives of thirty-two chydorid taxa were collected. Minimum variance clustering and principal components analysis (PCA) of the dat set allowed the recognition of three geographically distinct sampling site groups: Western, Central Lowlands and Countrywide. Seven groups of chydorid taxa were identified on the basis of their total frequencies of occurrence, the frequency of cooccurrence of the taxa and occurrence on substrates. Several taxa were shown to have distributions restricted to particular lake groups.