Molecular Systematics, Biogeography, and Invasion Identity of Neogobiin Fishes

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The objectives of the investigation are to elucidate the evolutionary history, species identifications, and biogeographic diversification patterns of a remarkable endemic "species flock" of fishes native to the Black and Caspian Seas that has become a growing problem in its invasions of North American and Eurasian ecosystems. Many ecologists believe that such introductions of exotic species pose one of the most serious threats to native ecosystems worldwide. For example, the ecology of the North American Great Lakes has been restructured by waves of invaders that were accidentally introduced from ships' ballast water, including the Ponto-Caspian round goby and its zebra mussel prey. Two goby species - the round goby and the tubenose goby - invaded in the early 1990's, and the former spread rapidly to all five Great Lakes. Invasions by suites of related taxa increasingly appear to characterize exotic communities, which may facilitate one another. Several other neogobiin species also have been "on the move" in Eurasian waterways due to construction of canals, shipping, and habitat disturbances. Some of these - including the monkey, bighead, and racer gobies - are predicted to invade North America and may already be here, but are not yet identified. This study will develop diagnostic DNA sequence characters and construct taxonomic keys to permit correct identification of the neogobiins at all life history stages. In addition, the sequence data will provide the means to elucidate the sources of exotic invasions, identify cryptic species, analyze whether relatived species also invade or are likely to, and determine whether new colonizations arise from spread or from independent introductions. Results will be of fundamental use to ecologists, environmental managers, and international agencies such as the Aquatic Nuisance Task Force in allowing rapid and cost-effective identification of taxa, and delineating their population area of origin.