. Bulletin. Natural history; Natural history. 108 Illinois Natural History Survey Bulletin Vol. 30, Art. 2 APR MAY JUN JULY AUG SEP OCT MAY JUN JULY AUG 1962 1963 Fig. 4.—Growth and condition (C) of largemouth bass of the dominant 1961 year-class over the 1962 and 1963 growing seasons In the control pond Beta (dots), cropped pond Gamnna (circles), and add-stock pond Delta (rectangles). Cooper et al. {1963) demonstrated that heavy cropping of a population of year- ling bass in a Pennsylvania pond caused substantial improvement in growth and condition, and in surplus production. It should
. Bulletin. Natural history; Natural history. 108 Illinois Natural History Survey Bulletin Vol. 30, Art. 2 APR MAY JUN JULY AUG SEP OCT MAY JUN JULY AUG 1962 1963 Fig. 4.—Growth and condition (C) of largemouth bass of the dominant 1961 year-class over the 1962 and 1963 growing seasons In the control pond Beta (dots), cropped pond Gamnna (circles), and add-stock pond Delta (rectangles). Cooper et al. {1963) demonstrated that heavy cropping of a population of year- ling bass in a Pennsylvania pond caused substantial improvement in growth and condition, and in surplus production. It should be pointed out that the Pennsyl- vania study was a comparison of data from a single pond in different years while our comparisons were of data from different ponds in the same year. As emphasized earlier, differences in environments frequently masked the in- fluences of our experimental treatments. While our rates of surplus production were consistently greatest in cropped ponds, and lowest in the add-stock ponds, rates of growth and condition showed less conformity. Our most complete data comparing growth with condition are for the 1961 brood over the 1962 and 1963 growing seasons since this was the age group that was most abundant and the most heavily cropped over that period. Fig. 4 presents growth and condition curves for the 1961 year-class based on approx- imately bimonthly samples over most of the 1962 and 1963 growing seasons, with the terminal points in 1963 repre- senting averages of all fish in the final censuses. Growth and condition curves are based on identical samples. After mid-June, 1962, the growth curve repre- senting the cropped population ranked higher than that of either companion population and the margin of difference increased steadily throughout 1963. Coefficients of condition computed from the same samples were extremely variable from one sampling period to. Please note that these images are extracted from scanned page images that may have been dig
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