Foraging behaviors of a predatory snail (Hexaplex trunculus) in group-attacking

Abstract

The behavior of a group of predators may have effects which cannot be predicted using data from a solitarily observed predator however in many experimental studies on the aspects of predation, one predator at a time have been examined. In the present study consumption rates of H. trunculus were tested with experimental setups that allow communal feeding, and some reassessments were attempted to be made on the foraging capabilities of this species, which can be used in ecology and aquaculture studies alike. Furthermore, the influence of predator hunger level was evaluated in an auxiliary experiment. Experiments were designed as two equal periods. The prey species Mytilus galloprovincialis were offered to the snails in four size groups. Consumption rates of H. trunculus were found to be highly consistent between the first and the second period and were about 0.09 mussel snail-1 day-1; higher than previous reports. In the hunger level experiment which had a shorter experimental duration, consumption rates were quite high in the beginning and were decreased drastically after the first period as expected. Consumed prey sizes did not differ between main and hunger level experiments; therefore, snails did not make a particular size selection caused by their hunger level.