Early Life History Characteristics of Age‐0 White Crappies in Response to Hydrology and Zooplankton Densities in Normandy Reservoir, Tennessee

Age‐0 white crappies Pomoxis annularis were collected in 1994 and 1996–1998 in cove samples from Normandy Reservoir, a 1,307‐ha flood control impoundment on the upper Duck River in southcentral Tennessee. Age‐0 crappies were measured (TL, mm) and weighed (g); otoliths were removed and hatch dates and daily growth rates determined for the aged fish. Across years, crappies hatched as early as 13 April and as late as 6 June. Hatch date and length‐frequency distributions were unimodal in all years. The first hatch date and mean hatch date of white crappies were positively correlated with the first day the reservoir achieved full pool. Growth ranged from 0.41 to 0.90 mm/d; it did not appear to be affected by the density of white crappie larvae but may have been affected by that of crustacean zooplankton. Within each year, earlier‐hatched fish grew at slower rates than later‐hatched fish, probably owing to the warmer water temperatures experienced by later‐hatched fish. However, year‐classes that hatched earlier grew faster on average, perhaps due to reduced competition from fish species that spawned later than white crappies. The growth of age‐0 white crappies appeared to be little affected by spring or summer water level events, but it may have been influenced by hatch date and zooplankton density.