Influence of temperature on the population dynamics of the guppy (Poecilia reticulata)

In the present study, a mathematical model was developed to evaluate fish demography under different temperature conditions. The target organism was Poecilia reticulata whose population reared under controlled conditions was subjected to different temperatures (24, 28 and 30 degrees C) in order to understand how this affects the organisms. Individual fish lengths were recorded before and after the experiment, as well as data related to birth and mortality before, during and after the acclimatization period. From the life cycle of P. reticulata, six differential equations were derived, one for each stage of development, which allowed us to better model population growth as a function of time and environmental variables, in this case, water temperature. Subsequently, the stationary points of these equations were calculated, which allowed a stability analysis of the system to be carried out. In addition, a population projection was made using the data obtained from the proposed model, which allowed to better understand how different temperatures affect the size and dynamics of the P. reticulata population. Significant differences were found in Dunn's test for fish length among the different temperature treatments, suggesting a direct relationship between water temperature and the growth of these organisms. This study provides valuable information on how environmental conditions can influence the population dynamics of P. reticulata.