ding to horizontal, longitudinal and vertical movements, respectively; Fig. 1). The sampling rate of the data loggers was set at 100 Hz. In order to attach the data loggers to the fish, 4 hooks with barbs were fastened around the data loggers using nylon thread and used to fix them on the dorsal surface of the fish, anterior to the dorsal fin and parallel to the body axis, in the first 10 fish (Fig. 1).