Observing Fish Behavior

On today's dive, we went out to observe the behavior of the threespot damselfish. In general, damselfish species are territorial, thus show aggression towards other fish species when in close proximity to their territory. We each had to local an individual threespot damselfish guarding it's own area, which is usually an algae garden. Once we located a fish, we observed for a few minutes to figure out how big their territory was, so we could place a 50cm bar in the middle to help in determining the distance the fish would travel to attack an approaching fish. After placing the bar, we waited five minutes to allow the fish to acclimate to the disturbance and tour presence. When this period was over, we began recording the number of attacks with the estimated distance the fish would travel. We also recorded the number of fish that were able to be within the damselfish's territory without being attacked. This observation period lasted for 30 minutes. When this was completed we headed back to the surface to start data analysis.