Characterization of the growth of rainbow trout (Oncorhynchus mykiss) in Lake Titicaca using nonlinear models

Abstract

This research was carried out with the objective of characterizing the growth of rainbow trout (Oncorhynchus mykiss) in Lake Titicaca using nonlinear models, from which points of biological and economic interest were identified, as well as predictions of food requirements to improve the productive and economic performance. The information used corresponds to the company Perú Pacífico located in the district of Capachica, province of Puno. The models analyzed were Logistic, Gompertz and Richards that were estimated using SAS ® NLIN and the Marquardt algorithm. The Richards model showed a higher coefficient of determination (R²). That is, it adequately describes and predicts trout growth in Lake Titicaca, under specific management conditions. The Logistic and Gompertz models showed lower predictive capacity when overestimating and underestimating the weight in the initial phase of growth, while in the final phase, they underestimate and overestimate, respectively. The growth profile shows slow weight increases in the adaptation phase to the environment, accelerated to the point of inflection, tends toward an asymptotic value as it approaches adulthood, and has a sigmoid shape, typical in trout. Finally, it has been determined the period of adaptation to the environment, the point of inflection, the time in which they would reach commercial weight (200, 250, 330 and 500 gr), and the requirement of food at certain times of a productive cycle of 269 days.