Prey Capture Assay: A Method to Study the Prey Capture Behavior of Zebrafish Larva

- To begin, place a zebra fish larva in a recording chamber, such as a glass-bottomed well, in which a larva can swim. Collect paramecia, the prey, with the help of a micropipette, and place them in the recording chamber. Next, put a small drop of water at the center of the cover slip and place it over the chamber to avoid an air bubble.

Now place the chamber on the lighting system equipped with a white LED ring light to eliminate shadows and make the organisms clearly visible. Observe the prey capture behavior using a behavioral recording system. As soon as the prey comes in sight, the larva converges its eyes and takes a J turn to orient its body towards the prey and captures it. We can quantify the prey capture behavior by recording the number of paramecia remaining in the chamber over a period of time. In the following protocol, we will assess the prey capture behavior of the zebra fish larva after the laser ablation of specific neurons.

- After setting up the behavioral recording system and placing a larva into a recording chamber according to the text protocol, use a micropipette to collect 50 paramecia and place them in the recording chamber. To place a cover slip on top of the recording chamber, put a small drop of water on the cover slip before placing it on the water surface of the recording chamber to avoid introducing air in the chamber.

Place the recording chamber in the lighting system. Then start the time lapse recording at 10 frames per second for 11 minutes. Finally, carry out analysis according to the text protocol.