Meeting Abstract

100-1   10:15 - 10:30  What it takes to overcome an anemone enemy and attack your snack: Hunger drives risky decisions in a specialist predator of dangerous prey Otter, K*; Gamidova, S; Katz, PS; University of Massachusetts Amherst; University of Massachusetts Amherst; University of Massachusetts Amherst kotter@umass.edu

When hunting and feeding, animals make cost-benefit decisions about where, when, and how to find food while avoiding predation. In this study, we focused on the specialist nudibranch predator Berghia stephanieae, which eats a single species of sea anemone, Exaiptasia diaphana. Sea anemones also predate upon foraging nudibranchs. This provides a unique opportunity to study how hunger influences the approach-avoidance decision-making of a specialist predator of dangerous prey. We characterized the feeding behavior and the probabilities of response to contact with the Exaiptasia in starved and sated animals to understand approach-avoidance decision making using machine-learning based software (DeepLabCut). We found that food-depriving Berghia decreased the probability of it exhibiting an avoidance response after contact with its prey. When a cohort of animals were tested over periods of food-deprivation, we found that the behavioral differences shifted gradually, indicating that hunger state has a graded effect on decision-making. We also found that the shift in response probabilities was caused by an increase in the number of appetitive responses, while the number of avoidance responses was the same across states. Thus, the choice of whether to pursue or evade is incrementally modulated by the animal’s internal state; like other animals, they make riskier choices when hungry. These behavioral results provide insight that the neural circuitry underlying this decision-making is likely not driven by a discrete binary switch in a command-like neuron, wherein hunger signals shift the behavioral output from an avoidance default.