. Bulletin. Natural history; Natural history. 52 Illinois Natural History Survey Bulletin Vol. 27, Art. 1 teran larvae, amphipods, and mayfly the warmouths used in the present study nymphs and with a comparatively high are as follows: consumption of fish and dragonHy nymphs, 1. There was a regular increase in the fig. 6. During the spring of 1949, when number of annuli accompanying an in-. OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV 1948 1949 Fig. 17.—Coefficient of condition of 392 warmouths of three size groups ( inches, inches, inches) collected from Park
. Bulletin. Natural history; Natural history. 52 Illinois Natural History Survey Bulletin Vol. 27, Art. 1 teran larvae, amphipods, and mayfly the warmouths used in the present study nymphs and with a comparatively high are as follows: consumption of fish and dragonHy nymphs, 1. There was a regular increase in the fig. 6. During the spring of 1949, when number of annuli accompanying an in-. OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV 1948 1949 Fig. 17.—Coefficient of condition of 392 warmouths of three size groups ( inches, inches, inches) collected from Park Pond, early October, 1948, through early November, 1949. Warmouths collected and weighed in the summer of 1948 were so few in num- ber that data on them were not included in the graph. the warmouths were eating high percent- ages of crayfish (volume) and damselfly nymphs (frequency), the condition of these fish was steadily improving. The rela- tively good condition of warmouths during the summer of 1949 was associated with the extensive use of mayfly nymphs, cad- disfly larvae, and crayfish. There were no consistent differences in condition between male and female war- mouths in Park Pond. Scale Method of Calculating Growth The method of calculating warmouth growth from fish lengths and scale meas- urements is a composite of methods devel- oped by several authors but generally fol- lows the procedures suggested bv Hile (1941). Validity of the Annulus as a Year- Mark.—Age and growth studies made from the scales of warmouths in Venard Lake and Park Pond indicate that the an- nulus is a reliable year-mark in this spe- cies. Hile (1941:201-4) outlined the most important features of a valid annu- lus. Four points used to test the validit}' of the scale method of age determination for crease in size of fish, and fish assigned to any single age group were within a cer- tain length range, table 18. 2. Lengths calculated from scale meas- urements agreed reasonably well with ac- tua
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