Detecting Predators by Kinetic Dialogs in Schooling Fish
L. Levin

When a potential prey perceives a movement in its environment, it may flee, hide, or freeze, with different costs in energy, time, and danger in relation to a would-be predator. After some time with no new stimulus, by and by, the potential prey may risk a probe movement: the animal moves on out of its refuge exploring the area. If a predator is there it will probably react by orienting to the stimulus in preparation for an attack. This increases his own exposure to the interact or in a very short time after the probe movement. The reciprocal situation occurs when the initiator is the predator. This sequence, together with the relative direction of the movements (approach/withdrawal) we call “kinetic dialogs (DK)”. The rules of kinetic dialogs are based on the temporal correlation (temporal contiguity or contingency) of the reactor’s movements with those of the actor, and on the relative direction of those movements. A period of increased sensitivity would follow the probe during which even a very subtle moving away or approaching object will elicit attack or escape reactions. Thus, the KD system would be a two- component discriminator formed by contingency and sign, which aid the individual in discriminating hidden predators or preys. In this work, we test the case of detecting predators by KD in the following way. We arranged a computer-driven tracking system which directed a small ball to any fish in a school of 12 palmettos (Mettynis Luna) which appeared over a black screen (a probe movement). This contingent group showed a propagated hiding reaction not demonstrated by a similar group of fish which saw the same, yoked stimulus whose movements were independent of those of the fish. This result gives support to the idea that during predator-prey recognition kinetic dialogs, based on coupled interactions, operate.

Full Text: PDF     DOI: 10.15640/aijb.v4n1a2