Where is my mate ?-Real-time 3-D fish tracking for interactive mate-choice experiments

Virtual 3-D fish stimulus animations are a powerful tool in fish behaviour research. Besides the option to increase standardisation of such experiments it opens the possibility to change stimulus’ morphology or colouration. The next evolution step in virtual stimulus animations is the ability of interaction between live and virtual fish. Since the virtual stimulus fish can not see its live counterpart and consequently can not interact with it, such systems require a reliable real-time tracking of the live fish. In this paper we present an easy-to handle method for fully-automatic real-time 3-D tracking of fish. The method was already tested in practice successfully.