Ecological consequences of laterality in sticklebacks

Behavioral laterality, the presence of side biases in bilateral animals, is a widespread phenomenon in the animal kingdom. It is believed to provide fitness advantages by facilitating more efficient information processing in the brain. It is hypothesized that behavioral laterality may correlate with personality traits if emotional reactions are processed differently in the brain hemispheres. This potential covariation between laterality and personality could help explain the observed maintenance of variability in personality within populations. However, the existing literature on this topic presents mixed results. To gain a deeper understanding of the relationship between behavioral laterality and brain function, this study focuses on fish, which offer a unique advantage due to the clear separation between the hemispheres. This thesis investigates how the correlation between laterality and personality changes during early development, shedding light on the developmental aspect of laterality. In addition, the effect of growth and sexual maturity on laterality is analyzed through a comparison of different age groups. This examination aims to determine whether changes in laterality occur as individuals progress through different stages of maturation. Finally, the thesis explores the potential link between behavioral laterality and fitness in coping with predators. By examining how laterality influences an individual's ability to respond to predation threats, insights into the adaptive significance of laterality can be gained. Overall, this research project contributes to the current understanding of behavioral laterality by investigating its relationship with personality, developmental changes, and fitness-related aspects.