Behaviour of personality-screened juvenile Oreochromis niloticus in different challenges: Bold fish present more exploratory capacity and learning to face imposed challenges

Abstract

The investigation of cultivation and management techniques that take into account behaviour and animal welfare becomes important due to their direct relationship with animal performance. This study aimed to classify juvenile Oreochromis niloticus by personality and compare their performance at exploration and competition tasks. The new object test was used to select bold and shy animals, which were then tested to see which first approached an object. The food competition test involved placing three feed pellets inside a cylinder and measuring the time taken until the pellet was eaten. The new object test found bold animals with a shorter mean time to approach the object than shy animals approaching 65% of the first object when compared to shy. The food competition test found that the bold animals ingested the first pellet more times and with a shorter average time of ingestion than shy animals, no difference in the second intake, whereas the results for the third were same as those for the first. Shy animals had higher intake of the second pellet. Bold animals explored their environment faster in both challenges, while shy individuals exhibited ability to learn from the challenges imposed in the study.

Key words
Stress; new object; feeding; personality