All foraging trials will be conducted using Artemia prey. Use of this species will minimize the potential for prey behaviors to influence the foraging behavior of the predators. We will conduct experiments in which the foraging behavior of a range of sizes of both species of predators will be recorded in static cylindrical chambers. These data will be analyzed to develop size-dependent functions for foraging measures such as predator swimming speed, attack rate, reactive distance, attack speed, pursuit length and duration specific for each size of cylinder. Estimates of each behavioral ability will be compared among cylinder sizes in an analysis of variance to test the null hypothesis of equal responses.
Differences indicate the presence of scale limitations in interpreting behaviors.
We will also explore the behavioral responses in the 200 and 400 mm diameter cylinders in oscillating and non-oscillating modes to assess whether scale effects differ between static and turbulent conditions. Experiments will be conducted using both fish larvae and a gelatinous zooplankton. Larvae of both species will be kept at temperatures and salinities optimal for growth and survival, and fed cultured rotifers and enriched Artemia until required for experiments. Before experiments, larvae will be transferred to holding tanks to acclimate to experimental conditions. The ctenophore Mnemiopsis leidyi is locally abundant from May onwards and can be easily collected in glass or plastic containers from both CBL and HPL piers.