Satiety differentially modulates feeding steps in the jellyfish Cladonema.

Following a meal, animals exhibit satiety, a state of decreased motivation to feed. Satiety is observed throughout the animal kingdom, suggesting ancient underlying mechanisms. Here, we investigate how satiety alters feeding in jellyfish, species that lack a centralized brain. Using comprehensive ethological analyses in Cladonema, a jellyfish with highly stereotyped, sequential feeding behavior, we show that satiety disorganizes its feeding sequence and delays all feeding steps, thus reducing food consumption. Surprisingly, isolated tentacles from fed jellyfish displayed satiety, thereby showing sustained and autonomous signaling of this state. Moreover, temporal dynamics of inhibition differed among feeding steps. Taken together, our results highlight complex satiety signaling in this species, suggesting multiple underlying signals.