Display vigour and subsequent fight performance in the siamese fighting fish, betta splendens.

The display of 24 individual male Siamese fighting fish to an unresponsive stimulus conspecific was measured, and the fish were then placed together in pairs. For 11 of the 12 pairs, the outcome of the aggressive interaction which ensued was predicted by the gill cover erection durations obtained in the pre-fight isolate tests. The implications of this result for theories of display function are discussed.