The effects of color patterns on the aggressive behavior of Tilapia mariae (Boulenger)

The present study uses dummy presentations to explore the effects of color patterns on behavior. Four patterns are used: spotted, barred, spotted/barred, and plain. Of 15 behaviors observed only 5 were found to be affected by color patterns. These were: Lateral Display, Frontal Display, Charge, Tailbeat, and Bite. The results demonstrate that the spotted pattern, indicative of a territorial animal, elicits high levels of Frontal Display, Bite, Tailbeat, and Charge and low levels of Lateral Display while the barred pattern, indicative of a submissive or escaping animal, has the opposite effect. The spotted/barred pattern elicits intermediate levels of Bite, Charge, and Lateral Display but levels of Frontal Display and Tailbeat similar to that seen in the presence of the barred pattern. The plain pattern elicits low levels of all the above behaviors. These results are discussed in terms of internal state changes.