# Satiety differentially modulates feeding steps in the jellyfish Cladonema

## TL;DR

This study shows that satiety disrupts the feeding sequence in Cladonema jellyfish, even without a centralized brain.

## Contribution

The research reveals satiety signaling in jellyfish through disorganized feeding steps and autonomous tentacle responses.

## Key findings

- Satiety disorganizes and delays feeding steps in Cladonema.
- Isolated tentacles from fed jellyfish show satiety, indicating autonomous signaling.
- Different feeding steps are inhibited with distinct temporal dynamics.

## Abstract

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.

•In hungry Cladonema jellyfish, feeding is a well-organized sequence of steps•Ad libitum feeding satiates the jellyfish, disorganizing and delaying these steps•Satiety inhibits the feeding steps with distinct temporal dynamics

In hungry Cladonema jellyfish, feeding is a well-organized sequence of steps

Ad libitum feeding satiates the jellyfish, disorganizing and delaying these steps

Satiety inhibits the feeding steps with distinct temporal dynamics

Biological sciences; Zoology; Ethology