The effects of temperature on feeding in zooplanktivorous walleye, Stizostedion vitreum, larvae

We examined the prey capture process in walleye larvae (9.8-18.0 mm mean length) feeding on zooplankton (density 1501 super(-1)) in laboratory aquaria at 15, 18.5 and 22 degree C. Larvae were starved for greater than or equal to 8 h prior to the experiment and only allowed to feed for less than or equal to 10 min during the experiment in order to minimize the influence of gut processing or satiation on feeding behaviour. Prey consumption ( mu g min super(-1)) increased exponentially and prey capture success (%) increased logarithmically with mean walleye length. Prey consumption and attack rate (strikes min super(-1)) increased significantly with increasing temperature. The effect of temperature on capture success was slight (2% increase from 15 to 22 degree C) and not significant. Walleye showed positive electivity for medium-sized prey (0.3-0.6 mm body width, mostly Ceriodaphnia quadrangula), negative electivity for small prey (