Information Exchange between a pair of Physically Separated Zebrafish

Hao-Yun Hsu¹, I-Shih Ko¹, C. K. Chan¹, chikeung chan^1*

¹Institute of Physics, Academia Sinica, Taipei, Taiwan

* Presenter:chikeung chan, email:ckchan@gate.sinica.edu.tw

Experiments with physically separated but visually interacting Zebrafish pairs are investigated to study the effects of separation distance (d) on their information exchange. We find that the forms of their motion trajectories can be strongly depend on d in some pair of fish. When d is small, the pair seem to engage mutually with each other; the two trajectories showing similar form. However, when d is larger than some critical distance, the originally similar trajectories turn into different forms. From these different forms of the trajectories, one can deduce that one of the fish is an information source while the other is a receiver. With this designation of direction of information flow (DIF), the information tool of transfer entropy (TE) based on trajectories and symbolic dynamics are then used to check the validity of this designation of DIF. We find that results from TE is inconclusive; suggesting that new tool for the DIF detection is needed.

Keywords: information theory, transfer entropy, causality, zebrafish