9307132 Mayden This research involves a detailed phylogenetic study of North American cyprinid fishes using a combination of morphological features and nucleotide sequences of mitochondria ribosomal genes. This phylogeny will be used to establish a stable classification of these fishes and to examine patterns of morphological, ecological, and behavioral diversity within this important group of fishes. %%% Cyprinid fishes form a major component of aquatic ecosystems in North America, representing nearly 30% of the fish fauna. Therefore, it is important to understand the biological diversity of this group. A more reliable understanding of the relationships of these fishes will contribute greatly to our understanding of the biogeography, ecology, and behavior of this important group of fishes. In addition, this research will help identify unique populations and species, a requisite for any management scheme directed toward the conservation of aquatic ecosystems in North America.