coordinated and cohesive movement of two small conspecific fish induced by eliciting a simultaneous optomotor response协调和粘性流动的两个小同种的鱼引起诱发同时视动的反应.pdf

Coordinated and Cohesive Movement of Two Small Conspecific Fish Induced by Eliciting a Simultaneous Optomotor Response 1 1 1 1 2 Haruka Imada , Masahito Hoki , Yuji Suehiro , Teruhiro Okuyama , Daisuke Kurabayashi , Atsuko 1 3 1 1 1 Shimada , Kiyoshi Naruse , Hiroyuki Takeda , Takeo Kubo , Hideaki Takeuchi * 1 Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan, 2 Department of Mechanical and Control Engineering, Tokyo Institute of Technology, Tokyo, Japan, 3 Laboratory of BioResource, National Institute for Basic Biology, Okazaki, Aichi, Japan Abstract Background: In animal groups such as herds, schools, and flocks, a certain distance is maintained between adjacent individuals, allowing them to move as a cohesive unit. Proximate causations of the cohesive and coordinated movement under dynamic conditions, however, have been poorly understood. Methodology/Principal Findings: We established a novel and simple behavioral assay using pairs of small fish (medaka and dwarf pufferfish) by eliciting a simultaneous optomotor response (OMR). We demonstrated that two homospecific fish began to move cohesively and maintained a distance of 2 to 4 cm between them when an OMR was elicited simultaneously in the fish. The coordinated and cohesive movement was not exhibited under a static condition. During the cohesive movement, the relative position of the two fish was not stable. Furthermore, adult medaka exhibited the cohesive movement but larvae did not, despite the fact that an OMR could be elicited in larv