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a Composition of the fish community in Browns Park, Lodore Canyon, Whirlpool Canyon, and Island-Rainbow Park reaches 2002-2004.-A total of 209,466 specimens representing 9 native and 19 non-native species and 7 hybrid combinations were captured by all sampling gears during 2002 to 2004 (Table 3). Flannelmouth sucker Catostomus latipinnis was the most common native fish captured by all sampling gears, followed by bluehead sucker Catostomus discobolus, mountain whitefish Prosopium williamsoni, speckled dace Rhinichthys osculus, roundtail chub, mottled sculpin Cottus bairdi, Colorado pikeminnow, bonytail Gila elegans, and humpback chub. No razorback suckers or mountain suckers were captured during this study; both taxa were previously collected (Holden and Crist 1981). Hybrids of razorback sucker and other sucker species were captured and will be discussed later in this report. The most abundant non-native fish species captured by all gears was red shiner Cyprinella lutrensis, followed by sand shiner Notropis stramineus, fathead minnow Pimephales promelas, and redside shiner Richardsonius balteatus, all small-bodied fishes. The most abundant large-bodied non-native fishes included white sucker Catostomus commersoni (mostly small-bodied specimens captured), common carp Cyprinus carpio, channel catfish Ictalurus punctatus, brown trout Salmo trutta, and smallmouth bass Micropterus dolomieu. Of taxa considered predaceous or potentially so, channel catfish, brown trout, smallmouth bass, and green sunfish Lepomis cyanellus were most abundant. Active sampling gears (seining and electrofishing) captured the most fish. Drift net samples were dominated by larvae or small juveniles (usually 5 to 25 mm TL), seine samples by small-bodied fishes (usually 20 to 75 mm TL), and trammel nets and electrofishing captured mostly large-bodied fishes (usually 150 mm TL or greater). Seining yielded eight native and 17 non-native species, and four hybrids. Flannelmouth sucker, bluehead sucker, mountain whitefish, and speckled dace, in descending order of abundance, were the most common native fishes collected. Red shiner, sand shiner, fathead minnow, and redside shiner, in descending order of abundance, were the most abundant non- native taxa collected. Seining also captured the highest proportion of non-native fishes at 92.4%, 19