{"pk":62791,"title":"Diets of Largemouth Bass (Micropterus salmoides) in the Sacramento San Joaquin Delta","subtitle":null,"abstract":"Largemouth Bass (\nMicropterus salmoides\n) were introduced into the Sacramento-San Joaquin Delta (the Delta) over 100 years ago. In the last 2 decades, the abundance of centrarchids (including Largemouth Bass) in the littoral zone has increased, while some native fish and fish that were previously abundant in the pelagic zone have declined. Largemouth Bass are now one of the most abundant piscivores in the Delta. Understanding the ecology of this top predator — including a comprehensive understanding of what prey are important in Largemouth Bass diets — is important to understanding how this species may affect the Delta fish community. To address this need, we conducted electrofishing surveys of Largemouth Bass at 33 sites every 2 months from 2008 to 2010, measuring fish fork lengths and collecting stomachs contents at each site. We characterized diets using Percent Index of Relative Importance for 3,004 Largemouth Bass, with samples that spanned all seasons. Amphipods dominated the diets of Largemouth Bass ≤175 mm FL year-round, with dipterans, odonates, and copepods and cladocerans representing other important diet items. Non-native red swamp crayfish (\nProcambarus clarkii\n) were the most important prey for Largemouth Bass >175 mm FL. Non-native centrarchids (including Largemouth Bass) and amphipods were important prey items as well. Prickly Sculpin (\nCottus asper\n) were the most frequently consumed native fish. Other native fish and pelagic fish species rarely occurred in Largemouth Bass diets, and we discuss trends in how the frequency of co-occurrence of these fishes with Largemouth Bass in the electrofishing surveys was associated with their frequency in Largemouth Bass diets. The Largemouth Bass in the Delta appear to be sustained largely on a diet of other non-natives that reside in the littoral zone.","language":"en","license":{"name":"Creative Commons Attribution 4.0","short_name":"CC BY 4.0","text":"Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.\n\nNo additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.","url":"https://creativecommons.org/licenses/by/4.0"},"keywords":[{"word":"Largemouth Bass, non-native predators, diet, predation, red swamp crayfish, centrarchids"}],"section":"Research Article","is_remote":true,"remote_url":"https://escholarship.org/uc/item/9mn0v9qb","frozenauthors":[{"first_name":"Kelly","middle_name":"L.","last_name":"Weinersmith","name_suffix":"","institution":"Dept. of Environmental Science and Policy\nUniversity of California, Davis\nDavis, CA 95616 USA\n\nDepartment of BioSciences\nRice University\nHouston, TX 77005 USA","department":""},{"first_name":"Denise","middle_name":"D.","last_name":"Colombano","name_suffix":"","institution":"Dept. of Wildlife, Fish, and Conservation Biology\nUniversity of California, Davis\nDavis, CA 95616 USA","department":""},{"first_name":"Andrew","middle_name":"J.","last_name":"Bibian","name_suffix":"","institution":"Dept. of Environmental Science and Policy\nUniversity of California, Davis\nDavis, CA 95616 USA","department":""},{"first_name":"Matthew","middle_name":"J.","last_name":"Young","name_suffix":"","institution":"Dept. of Wildlife, Fish, and Conservation Biology\nUniversity of California, Davis\nDavis, CA 95616 USA\n\nDiv. of Environmental Sciences\nCalifornia Dept. of Water Resources\nWest Sacramento, CA 95691 USA","department":""},{"first_name":"Andew","middle_name":"","last_name":"Sih","name_suffix":"","institution":"Dept. of Environmental Science and Policy\nUniversity of California, Davis\nDavis, CA 95616 USA","department":""},{"first_name":"J.","middle_name":"Louise","last_name":"Conrad","name_suffix":"","institution":"Delta Science Program\nDelta Stewardship Council\nSacramento, CA 95814 USA\n\nDept. of Environmental Science and Policy\nUniversity of California, Davis\nDavis, CA 95616 USA\n\nDiv. of Environmental Sciences\nCalifornia Dept. of Water Resources\nWest Sacramento, CA 95691 USA","department":""}],"date_submitted":"2019-01-18T18:47:15Z","date_accepted":"2019-01-18T18:47:15Z","date_published":"2019-03-19T07:00:00Z","render_galley":null,"galleys":[{"label":"","type":"pdf","path":"https://journalpub.escholarship.org/jmie_sfews/article/62791/galley/48472/download/"}]}