Behavioral strategy of adaptation of <i>Polypterus senegalus</i>(Polypteridae) with an increase in ambient temperature

Abstract

This paper investigates the effect of temperature increase on the behaviour of Polypterus under laboratory experimental conditions. To investigate the effect of a change in temperature regime, analysis of video recordings of animal behaviour over eight hours under acclimation conditions and under a constant temperature increase is used. The temperature increase occurred at a rate of 1,125°C/hour. The movement trajectories of the animals under normal conditions and under a sudden increase in ambient temperature are described. The paper presents results on the speed and activity of the fish movements and the number of acts of air entrapment by polypterus from the water surface. The studies show that the increase in temperature leads to an increase in the variability of the animals’ movement trajectories. A steady increase in temperature leads to an increase in the speed and activity of the animals’ movements. As the temperature regime changes, there is an increase in the number of acts of air capture from the water surface. The largest jump in activity change is observed in the second and third hours of temperature increase. The obtained material can serve as a basis for the development of ideas about the behavioural adaptation of bony fishes to the increase in ambient temperature. The observed regularities in the responses to temperature changes will make it possible to improve the technology of polypterus cultivation.