Desert Fishes Council, Alpine, TX, November 2001.

Native catostomids as prey of introduced largemouth bass in a central Arizona stream.

M.R. Schwemm & P.J. Unmack

Feeding ecology of largemouth bass, Micropterus salmoides, was examined in the lower Salt River, Maricopa County, Arizona. The stream reach is regulated by upstream dams, and occupied by a mixed community of native cypriniforms and a suite of non-native fishes. Stomach contents of 100 largemouth bass, ranging 77-204 mm TL, were classified and numerically quantified, and relative abundance of invertebrate and vertebrate prey items were evaluated. Although alternate fish prey was available, largemouth bass were biased toward native catostomids (desert sucker, Pantosteus clarkii, and Sonora sucker, Catostomus insignis). This substantiates negative interactions between native prey and predatory exotic fishes.