Life History of the Emerald Shiner, Notropis atherinoides, in Lewis and Clark Lake, South Dakota

The age, rate of growth, reproduction, feeding habits, and population dynamics of the emerald shiner (Notropis atherinoides) were studied from 10,375 fish collected in Lewis and Clark Lake, South Dakota. The population in this 28,000-acre reservoir consisted of four age groups dominated by young-of-the-year during the summer and fall and by age-group I during the spring and early summer. Age-group II was common only in the spring and early summer while age-group III was rarely encountered. Average lengths at first and second annulus formations were 66 and 84 mm. Females attained larger sizes than males after the first year. The spawning season extended from June through August. A rapid and precise method was devised for conducting food-habit determinations that could be analyzed statistically. Adult emerald shiners fed selectively on large zooplankton. A gradual change in young-of-the-year food habits was evident; fish smaller than 40 mm fed primarily on algae, whereas larger fish fed chiefly on ...