Efeito da coloração do ambiente sobre o comportamento e aprendizado de tilápia do Nilo

Abstract

Environmental characteristics are capable of modulating the physiology and behavior of individuals. The objective of this study was to investigate the influence of environment color on the behavior and learning ability of Nile Tilapia, Oreochromis niloticus, in T maze. Eighty-four tilapias with 12.81 ± 0.38cm and 35.98 ± 8.33g were used in the experiment. They were separated into six groups of fourteen individuals and placed in blue, green and black tanks and acclimatized for 15 days prior to behavioral observations. For the learning test, which lasted 15 days, three T maze were set up, one of each environment color. After the learning test, the T maze color was changed for 5 days. At the blue and black tanks, fish remained mostly at the top of the tank. At the green tank, they remained equally distributed in the water column. There were more agonistic encounters at the blue environment. Fish trained in the lack maze needed nine days to learn the task of leaving latency and feed. Those trained in the green maze needed 10 days, while individuals at the blue maze failed to learn the task. The color change affected the performance of the task learned by the animals in all colors. It can be concluded that the blue color stimulated agonistic behavior and interfered in the performance of learning tasks. The black environment was best suited for maintenance and testing of learning in Nile tilapia.