Visual behavior, anatomy, and physiology in the archerfish

The archer fish (Toxotes chatareus) exhibits unique visual behavior in that it is able to aim at and shoot down with a squirt of water insects resting on the foliage above water level and then feed on them. This extreme behavior requires excellent visual acuity, learning, and tight synchronization between the visual system and body motion. Watch an quick introduction about the archerfish in this National Geographics video.

The extreme visual behavior of the archerfish raises many important questions, such as the fish’s ability to compensate for air–water refraction and the neural mechanisms underlying target acquisition But perhaps most importantly, this behavior allows to observe the archerfish visual behavior overtly, making it an ideal animal model for vision research in animals, specifically marine animals. With brain structure very different than mammals,  this facilitates exploration of developmental and evolutionary aspects of vision and in particular the study of the emergence of universal visual mechanisms in nature.

Joining forces with Prof. Ronen Segev from BGU’s life sciences department, and incorporating iCVL’s interests and expertise in biological and machine vision, we’ve been studying various functions of the archerfish visual system, including anatomy, physiology, and behavior, and have been comparing it to human vision when applicable. Some of the results are particularly surprising as they suggest that without visual cortex this fish species has developed mechanisms and visual behaviors comparable to those found in the mammalian cortex. to peek into such capacities, we also leverage the ability to train the archerfish shoot targets presented on a computer screen, followed by controlled experiments where it follows carefully designed experimental procedures where target selection informs of specific visual function. A typical behavioral trial is shown in the video and selected studies on the archerfish follow in the papers below.

 

Papers

 

Acknowledgements

The various projects and studies made in this context were funded in part by different agencies including  The Israel Science Foundation (ISF), grants no. 502/07,  1619/07 , 207/11, 1274/11,  211/15, and 281/15, the Center for Complexity Sciences, The Human Frontiers Science Program, and the Rich foundation, and the Psychobiology Institute. We also thank the Frankel fund of the Cmoputer Science department, the Helmsley Charitable Trust through the Agricultural, Biological and Cognitive Robotics Initiative, and the Zlotowski center for Neuroscience, all at Ben-Gurion University,