Meeting Abstract
Archer fishes are social animals that forage for terrestrial insect prey by spitting streams of water from their mouths, causing prey to fall to the water surface, where it can be grabbed and consumed by the shooter. The fish must rotate its entire body in a vertical direction, so that the snout will protrude from the surface of the water, fire its shot, then return to a horizontal orientation so it can swim and capture the dislodged prey. We understand from previously published research that shooters are highly susceptible to conspecific theft of falling prey. It was the goal of the current investigation to quantify archer fish foraging behaviors, in order to determine if shooters can modify any aspect of their foraging behavior in order to reduce intraspecific theft. We investigated the following behaviors in the lab using individual and paired foraging archer fish: (1) maximum vertical rotation during spitting, and (2) vertical rotation time. We predict that altering rotation kinematics might allow shooters to gain an advantage over bystanders, perhaps catching a thief off guard. In pairs of foraging fish, we also investigated (3) time spent under prey, and (4) chasing, which we predicted would give shooters an advantage by patrolling or guarding locations where prey appear. Preliminary data for (2) vertical rotation time indicates that shooters do not alter the speed of rotation in a group compared to foraging alone. Data from (3) and (4) suggests that when in pairs, one aggressive individual will patrol beneath locations where prey will appear and will chase off the bystander, allowing sniped prey to be captured without contest. Overall, our findings suggest that archer fish use aggressive tactics, rather than kinematic changes, to reduce competition for prey when in pairs.
