Quantitative chemobehaviour of fish: an improved methodology

A behavioural-monitoring system (an octagonal fluviarium), and a time-series analytical technique, were developed to quantitatively determine the responses of fish to waterborne chemicals. The system used a quasi-circular channel in which fish moved freely through any one of 8 areas, receiving a predetermined dose of chemical stimulus. Response was monitored on video and spatio-temporal preferences recorded. The advantages were control of water-flow dynamics, elimination of wall-hugging, determination of temporal changes in response, and ability to correlate these last with odoriferous cues. Using zebrafish (Brachydanio rerio), the system showed that they could detect and respond to very low levels of L-alanine .001 M. The system is claimed to have extensive applications in studies of the chemoresponses of aquatic organisms generally (eg pheromones and pollutants).