Age and growth of the white crappie, Pomoxis Annularis Rafinesque, in Lake Waco, Texas

Abstract

The major collection of white crappie was from 17 July 1967, to 10 April 1968, by traps and gill nets. Other fish were taken by anglers and seines in June 1968. A total of 1142 fish were included in this study. Spawning season for Lake Waco crappie was from late February to early May and was at its peak in March and April. White crappie in Lake Waco may spawn after one year. Growth rate of Lake Waco white crappie was rapid. The average back-calculated total lengths(TL) for Lake Waco crappie for the last 4 years were as follows: 145mm for the first year’s growth, 216mm for the second age group, 271mm for the third age group, and 309mm for the fourth age group. In the white crappie scales started to develop on the caudal peduncle in fish 16mmTL. The first fully scaled fish observed was 31mmTL. The region between the dorsal fin and pectoral fin was the last place to develop scales. The mathematical expression of the length-weight relationship for the white crappie of Lake Waco is: log W = -5.6131 + 3.2954 log L where W= body weight in grams L=total length in millimeters. The body-scale relationship demonstrated a parabolar curve. The equation L=35.506219 + 1.215665 S + 0.000931 s2 fitted the body-scale relationship of Lake Waco white crappie well. Principal food items of white crappie were small fishes (mainly shads, Dorosoma cepedianum and D. petenense), aquatic insects, and small crustaceans. Lymphocystis was only found in the spring, and about 1.7 percent of the fish were infected. Infection by nematode parasites, Camallanus oxycephalus, was observed in the spring and summer, but infected fish showed no signs of weakness.