Response of Male Goby, Padogobius Martensii, To Aggressive Sound Playback Following Pre-Experimental Visual Stimulation

Abstract

AbstractThree playback experiments with a freshwater goby, Padogobius martensii, examined the effects of recent aggressive experience on the response of the territorial fish to the aggressive sound alone. Experiments 1 and 2 were conducted on a first group of fifteen resident males (i.e. males individually housed within laboratory tanks for at least 5 days). Experiment 1 simply consisted of playing back the sound to the resident male not exposed to social stimulation for at least 48 h. In experiment 2 the same male was exposed to its mirror image before the start of playback. Results showed that in experiment 1 males ignored or even tended to avoid the site of sound stimulation, whereas in experiment 2 they attended the sound site more frequently during the sound playback. In both experiments the mirror and the loudspeaker were placed on the same side of the tank. The third playback experiment was therefore developed to include mirror and loudspeaker on opposite sides of the tank. A different group of sixteen males was used for these experiments. Results showed that the sound playback may be more important than the mirror site in directing the approach response of the male. Furthermore, the magnitude of sound interference was positively correlated with the level of mirror aggressiveness shown by the male before playback. Functional implications of the responses to the aggressive sound alone for the territorial fish are discussed.