Control of self-motion in dynamic fluids: fish do it differently from bees

Area of Science:

• Animal behavior
• Neuroethology
• Biophysics

Background:

• Animals require self-motion perception to avoid collisions, particularly in fluid environments like air or water.
• Flying animals often use optic flow for flight control, but strategies for aquatic swimmers are less understood.

Purpose of the Study:

• To investigate if aquatic animals like zebrafish use optic flow for self-motion control similarly to flying insects.
• To compare zebrafish trajectories with bumblebee trajectories in a controlled visual environment.

Main Methods:

• Zebrafish and bumblebees were observed in an experimental tunnel with varying optic flow patterns on the walls.
• Trajectories and speed were recorded under conditions of strong, weak, or asymmetric optic flow.

Main Results:

• Zebrafish mean swimming speed was independent of the optic flow intensity from the walls.
• Zebrafish showed a preference for moving closer to the wall with stronger optic flow cues, contrasting with bumblebee behavior.

Conclusions:

• Zebrafish self-motion control in water may not rely on optic flow for speed regulation as seen in flying insects.
• The preference for strong optic flow suggests adaptations for navigation and collision avoidance in aquatic or low-visibility environments.