Calculation of search volume on cruise-searching planktivorous fish in foraging model

Abstract

Search volume of cruising planktivorous fish was calculated based on its detailed behavior. To examine the factors influencing search volume, a series of experiments were conducted by varying ambient conditions, such as structural complexity, light intensity, and turbidity. Pseudorasbora parva were used in experiment as predator and Daphnia pulex was selected as prey. The shape of scanning area of P. parva showed elliptic and the search volume changed drastically depending on ambient conditions. Compared with the results of previous foraging model, the search volumes of the fish under previous study were larger (1.2 to 2.4 times) than those from our study. These results on the changes in feeding rate can be useful in determining microhabitat requirement of P parva and other cyprinids with a similar foraging behavior The calculated search volume is compared with other foraging model and the effect of zooplankton-planktivore interactions on aquatic ecosystem is discussed.