Using infiltrated miniature mobile robots to monitor and influence the collective behavior of zebrafish

Having robotic agents introduced inside shoals of zebrafish Danio Rerio could allow scientists to monitor and influence the behavior of the animals in order to test their reaction to various stimuli, for instance when the fish are under the effect of drugs or genetic mutations in a non-invasive way. For these purposes, we have designed in the past years a multi-robots platform that allows a shoal of robotic fish to move in an aquarium among zebrafish thanks to a closed-loop control based on a visual tracking. The robots are composed of two parts: a wheeled mobile robot that can reach speed of 30 cms-1 and acceleration of 1 m/s2 which are typical for the zebrafish, and a lure, magnetically coupled with the mobile robot, moving inside an aquarium and directly in contact with the fish. As the robots are continuously powered, this system allows very long duration experiments, for instance in order to study the fish behavior for several days.

We recently performed experiments with mixed groups composed of half robotic agents and half zebrafish and could observe that the robots are at the same time able to interfere in the zebrafish shoal without changing their collective behavior, by mimicking their trajectories and locomotion, and also influence the fish shoal decisions when desired.

This innovative system offers a new approach for social behavior studies of zebrafish and other species of small fish. In future, we will implement more sophisticated controllers that can adapt to the zebrafish in order to study more deeply the zebrafish behavior and social interactions.