title: Influence of robotic shoal size, configuration, and activity on zebrafish behavior in a free-swimming environment.
abstract: In animal studies, robots have been recently used as a valid tool for testing a wide spectrum of hypotheses. These robots often exploit visual or auditory cues to modulate animal behavior. The propensity of zebrafish, a model organism in biological studies, toward fish with similar color patterns and shape has been leveraged to design biologically inspired robots that successfully attract zebrafish in preference tests. With an aim of extending the application of such robots to field studies, here, we investigate the response of zebrafish to multiple robotic fish swimming at different speeds and in varying arrangements. A soft real-time multi-target tracking and control system remotely steers the robots in circular trajectories during the experimental trials. Our findings indicate a complex behavioral response of zebrafish to biologically inspired robots. More robots produce a significant change in salient measures of stress, with a fast robot swimming alone causing more freezing and erratic activity than two robots swimming slowly together. In addition, fish spend more time in the proximity of a robot when they swim far apart than when the robots swim close to each other. Increase in the number of robots also significantly alters the degree of alignment of fish motion with a robot. Results from this study are expected to advance our understanding of robot perception by live animals and aid in hypothesis-driven studies in unconstrained free-swimming environments.
authors.affiliation: Indraprastha Institute of Information Technology Delhi (IIITD), New Delhi, India; Department of Mechanical and Aerospace Engineering, New York University Polytechnic School of Engineering, Brooklyn, NY, USA.
authors.forename: Sachit
authors.initials: S
authors.lastname: Butail
authors.affiliation: Department of Mechanical and Aerospace Engineering, New York University Polytechnic School of Engineering, Brooklyn, NY, USA; Department of Biology and Ecology of Fishes, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Polverino
authors.affiliation: Department of Mechanical and Aerospace Engineering, New York University Polytechnic School of Engineering, Brooklyn, NY, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Phamduy
authors.affiliation: Department of Mechanical and Aerospace Engineering, New York University Polytechnic School of Engineering, Brooklyn, NY, USA.
authors.forename: Fausto
authors.initials: F
authors.lastname: Del Sette
authors.affiliation: Department of Mechanical and Aerospace Engineering, New York University Polytechnic School of Engineering, Brooklyn, NY, USA. Electronic address: mporfiri@nyu.edu.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Porfiri
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004777:Environment; D005260:Female; D046352:Freezing Reaction, Cataleptic / Q000502:physiology; D008297:Male; D011336:Probability; D012371:Robotics / Q000295:instrumentation*; D012919:Social Behavior; D013037:Spatial Behavior; D013550:Swimming / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D015027:Zebrafish
keywords: Animal–robot interaction; Behavior; Robot; Zebrafish