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Size of prey was a major factor in food selection of bluegills as they increased in size (Werner 1974). Handling time of prey increases as bluegills reach satiation and the fish become more selective for size of the prey (Werner and Hall 1974). Generally, bluegills do not move far, but, in Folsom Lake, California, Rawstrom (1967) reported an average movement of 1.8 km. In winter, bluegills stay near the lake bottom but may move into shallow water or the surface of deep water in summer (Carlander 1977). Singer (1973) reported that 0-28% of the stomachs from bluegills (sample sizes ranged from 28 to 85 fish) taken from two backwaters on the lower Colorado River contained fish during 4 seasons over a two-year period. The highest use of fish in bluegill diets occurred during the spring and summer when young-of- the-year fish were available. Discussion Related to Potential Competition/Predation Bluegills are highly fecund and severe competition results in overpopulation accompanied with slow growth through stunting (Carlander 1977). Small bluegills feed on the same food items that are eaten by larger bluegills I, (Werner 1974). Therefore, competition can occur between fish of different hh'` sizes resulting in slow growth (i.e., stunting) as food resources become limiting. Since bluegills feed on the same food items as small Colorado squawfish, the potential for competition between the two species exists. In the Lower Colorado River Basin, bluegills moved into shallow coves in Lake Meade during the late spring and remained there during the summer. These fish were observed feeding on newly hatched largemouth bass fry (Allan and Romero 1975). Although predation on Colorado squawfish by bluegills should not be an (important factor because stocked squawfish would be too large to be consumed jby the bluegills, competition would probably be significant because bluegills "feed on newly hatched fish that would serve as forage for stocked Colorado squawfish. kl- Black Crappie NOTE: White crappies (Pomoxis annularis) are presently confined to Navajo Reservoir on the San Juan River. However, the black crappie is found throughout Lake Powell and the Colorado River to its confluence with the Gunnison River (Tyus et al=. 1982). It is abundant in Lake Powell but incidental in the mainstem rivers or their major tributaries. Since any stocking of crappies in the Upper Colorado River Basin would probably be the black crappie, this summary will be confined to that species. Habitat The black crappie prefers clearer, deeper, and cooler water of lakes and reservoirs than the white crappie and its range extends further north (Carlander 1977). It can also be found in slow moving streams or in eddies/backwaters of faster moving streams. Black crappies are almost always associated with aquatic vegetation or other substrate (i.e., submerged trees, rocky outcrops, etc.). This species is usually found in discrete, moderately large schools that are associated with the littoral zone of reservoirs when 8