A PC-aided video based system for behaviour observation of fish larvae and small aquatic invertebrates

A PC-aided video based behaviour observation system for fish larvae and small aquatic invertebrates is presented, tested, and discussed. A video camera is moved horizontally and vertically in front of a 90-litre observation aquarium by means of servo motors remotely controlled via a joystick. Camera focus is also controlled from the joystick. Camera movement and focusing cause voltage variations which are monitored by a PC and transformed into stereo coordinates and stored. Behaviour patterns are registered into the PC by the observer in real time. The aquarium is illuminated with infrared (IR) light to facilitate dark observations with an IR sensitive video camera. The system was tested with cod and plaice larvae and live prey. Results obtained compare well with literature data.