Food arousal in the pond snail, Lymnaea stagnalis

Abstract

Factors affecting food arousal were examined in a behavioral study of the freshwater, browsing pulmonate, Lymnaea stagnalis. Presentation of a food stimulus (sucrose) leads to a progressive decrease in interbite interval over the first four subsequent bites. This is thought to represent an increase in food-induced arousal. The latency to first bite is correlated with total number of bites in the first 5 min following application of food. Latency to bite is significantly reduced for up to 15 min following a brief food stimulus. Previous levels of food consumption do not significantly affect latency to bite (i.e., food responsiveness). However, hunger does lead to an increase in spontaneous biting activity in the absence of food (i.e., food search activity). Latency to bite is negatively correlated with a more general measure of behavioral arousal, the Behavioral State Score. These results are discussed in relation to previous work on other gastropod species. It is concluded that mechanisms of food arousal are adapted to the animal's habitat and life-style.