Visual motion cues are one of the most important factors for eliciting animal behaviour, including predator-prey interactions in aquatic environments. To understand the elements of motion that cause such selective predation behaviour, we used a virtual plankton system where the predation behaviour in response to computer-generated prey was analysed. First, we performed motion analysis of zooplankton (Daphnia magna) to extract mathematical functions for biologically relevant motions of prey. Next, virtual prey models were programmed on a computer and presented to medaka (Oryzias latipes), which served as predatory fish. Medaka exhibited predation behaviour against several characteristic virtual plankton movements, particularly against a swimming pattern that could be characterised as pink noise motion. Analysing prey-predator interactions via pink noise motion will be an interesting research field in the future.
Matsunaga, W. & Watanabe, E. Visual motion with pink noise
induces predation behaviour. Scientific Reports 2, 219 (2012).
[pdf download site]
[How to make a Medaka Fish Toy, YouTube Video]
We have uploaded "Flash-drag Effect: Optical Illusion 3D".
The video is available in YouTube (click URL described in the next line).
The video is also available in YouTube.
Further, a demonstration animation of depth perception has been uploaded.
& one more optical illusion (Geared flash-lag effect, 01/06/2012).