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removed and acetate, impressions were made for age determination. Fish which were tagged and released were measured and sexed on the basis of external characteristics, which were readily apparent during the spawning season. Results Spawning behavior Spawning in the St. Joe River occurred in aggregations of fish ranging in size from a hundred to a few thousand individuals. Spawning fish were apparently unconcerned with swimmers, but maintained a minimum distance of 1 to 2 meters and drifted away if approached too closely. Males outnumbered females by 50-100:1, and swarmed in a dense mass within a meter of the substrate. Individual males generally faced the current, but did not maintain a position at any single locus. No aggres- sive interactions between males were noted. Females cruised slowly along the fringes of the aggregation and in nearby areas or swam about quickly just above the males. Slowly cruising females were ignored by males or were followed half-heartedly by one or two. Rapidly moving females were followed closely by up to 8 males, who stayed below or to the side of the female with their heads even with or slightly ahead of the female's vent. Spawning occurred when a female and her entourage of males dipped to within a few centimeters of the substrate. Acts lasted 1 second or less and eggs and milt were only momentarily visible. Females arched their backs with vents close to the substrate, gaped their mouths, and vibrated. Males ducked alongside the female and vibrated. Spawners were besieged by a mass of darting males and all fish moved quickly away afterwards. Females typically veered away downstream, still followed by a few males. This action usually took them out of the observer's field of vision, but on one occasion a female was seen spawning three times at 4- to 6-second intervals in the same general area. Inspection of an area after spawning revealed many eggs adhering to the substrate or drifting into interstices. Further examination revealed eggs up to 15 cm below the substrate surface. Spawning was observed on both clear and rainy days. Activity seemed low until late morning, but continued at least until dust. Dark lateral bands were usually seen on spawning squawfish of both sexes. These bands were especially apparent of fish viewed underwater, but were also evident of fish removed from the river. Few fish observed or captured in portions of the river other than spawning sites were colored in this manner. Almost all fish in spawning aggregations exhibited this coloration and the few that did not were usually on the fringes of the activity. Limited observations made in the Clearwater River in 1980 revealed • behavior similar to that noted in the St. Joe River. One difference was 51