I am particularly interested in reconstructing the evolution of the genera of the South American suckermouth armored catfishes or plecos (Loricariidae) using morphological characteristics. I also explore in detail various types of morphological systems such as those related to wood-eating in some loricariid catfishes and accessory respiratory structures. Wood-eating is found in two genera of loricariid catfishes and is accompanied by changes in the bones and the evolution of large spoon-shaped teeth. Many loricariids breathe air and there is a large number of adaptations the fishes use to do so including what appears to be a unique evolution of a lung and a unique evolution of a swim-bladder from that lung. I am also involved in taxonomic revisions of many groups of loricariids as well as other fishes . In addition, I am active in exploring the biodiversity of the planet, particularly that of South America. Studies are underway in Venezuela and Guyana (photo above is taken at Kaiteur Falls in Guyana) to determine what fish species are there and what impact humans may be having on them. In addition, I have just begun work on African and North American minnows and barbs, and am working on a revision of the Southern Cavefish (Typhlichthys subterraneus). Recently, I have become more interested in understanding how shape and ecology has evolved. We are studying the evolution of these ecomorphological measurements to determine the evolution of fish communities, particularly those of minnows and cichlids. My students work on a variety of topics from ecology to phylogenomics.