7355 - Laserfiche WebLink

Home Browse Search

become lodged in the throats of fish predators may be incidental rather than common. In laboratory experiments, Colorado squawfish did not feed on channel catfish fry (including fish with spines removed) but selected trout or minnows that were offered (Bulkley and Berry 1985). However, the significance of Colorado squawfish mortality from choking on channel catfish during recovery efforts is unclear. Largemouth Bass Habitat The largemouth bass inhabits lakes, ponds, oxbows, and quieter portions of flowing waters (Miller 1975). It appears to prefer clear water with abundant vegetation or other cover such as stumps, dead trees, and tree roots and generally avoids high gradient reaches of streams (Carlander 1977). In Nebraska, this species was considered suitable for stocking into slightly alkaline waters with less than 900 ppm total alkalinity (McCarraher 1971). In the Upper Colorado River Basin, the largemouth bass is abundant in Lake Powell and common in quiet backwaters and gravel "borrow" pits along the the Colorado River below the confluence of the Gunnison River. It is also found in the littoral zone of Flaming Gorge Reservoir and some have been collected near the mouth of the Yampa River (Tyus et al. 1982'). In the Lower Colorado River Basin, largemouth bass appear to prefer quiet backwaters to the riverine habitat and apparently seek them out (Kennedy 1979). This same behavior has been observed in the Upper Basin. This species prefers habitat with a water temperature of 30 C with a range of 28 - 30 C (Ferguson 1958; Neill and Magnuson 1974). Food Habits c Fingerling largemouth bass feed primarily on microcrustaceans or zooplankton until they reach 30 mm in length but also bein to feed on fish when they are between 10-22 mm long (Carlander 1977). Between 30-75 mm, fry and fingerlings feed primarily on aquatic insects, amphipods, and decapods. Fish larger than 75 mm feed primarily on decapods such as'crayfish and fish. If available, -forage fish form the main diet of bass.larger than 100 mm. Largemouth bass primarily use sight to locate and orient to prey (Nyberg 1971), hence its preference for clear waters. Although it is a sight feeder, largemouth bass seem to be capable of feeding and maintaining populations in permanently turbid water if food is plentiful (Heimstra, Damkot, and Benson 1967). In studies of forage fish vulnerability, largemouth bass preferred golden shiners over other food items in the laboratory experiments but, in small ponds, tadpoles, crayfish, young black bullheads (Ictalurus melas), and green sunfish were preferred in that order (Lewis, Anthony ahd Helms 1961; Lewis et al. 1961; Lewis and Helms 1964). Food preference is correlated to (1) species availability (i.e., choices in food items), (2) abundance of prey, (3) vulnerability (i.e., ease of capture through conspicuousness, mobility, etc.), and (4) size.