Abstract
Several effects of fighting behavior on feeding was studied in the guppy, Poecilia reticulata. The size of males' fish used in this experiment was from 15mm to 23mm. The fish was placed alone without food during more than 72 hours.
Experiment 1 : Two fishes were put together in one aquarium. And then the fighting behavior of them were observed in 30 minutes (Exp. 1-1). After the observation they were removed separately into each cell of the basket, which was divided into two cells with a glass, and were given Daphnia as the food of them. All the social behavior of them in each cell was noticed for 30 minutes (Exp. 1-2).
Experiment 2 : Exp. 2-1 was carried out in the same method as Exp. 1-1. All the social behavior of the fish was observed in the aquarium used in Exp. 2-1 (Exp. 2-2), in order to eliminate the effect of the glass (Exp. 1-2) on the fish.
The results obtained are as follows :
1) The fighting behavior of the fish was the most active in the first ten minutes, so that the social order were established between them (Exp. 1).
2) The total numbers of Daphnia eaten ascended in about ten minutes in each fish (Exp. 1).
3) The dominant fishes ate occasionally small numbers of Daphnia from 10 to 30 minutes. On the other hand, the subordinate ones took food little in the period (Exp. 1).
4) When 100 numbers of Daphnia were given in the aquarium, two guppies fed them at first, and then the fighting behavior was observed in the pair. The subordinate fishes were prevented from the feeding behavior by the fighting behavior of the dominant ones (Exp. 2).
5) The dominant fishes ate more numbers of Daphnia than the subordinate did, though there was no statistical significant difference between them (Exp. 2).
