Meeting Abstract
95.2 Monday, Jan. 6 13:45 Foraging archer fish aggressively drive conspecific competitors away from reliable food sources BURNETTE, M.F.*; ASHLEY-ROSS, M.A.; Wake Forest University; Wake Forest University burnmf0@wfu.edu
Archer fishes (Toxotes spp.) are skillful hunters of terrestrial insects; firing streams of water from their mouths, they are capable of dislodging a prey item from overhanging perches positioned several body lengths away. Archer fishes are social, and bystanders will attempt to steal prey knocked down by shooters. Previously published research has found that even in small groups (3 individuals) thieves are highly successful when prey are spatially and temporally unpredictable. We asked what tactics are used by shooters and bystanders when prey are (1) spatially and temporally predictable and (2) when prey are spatially but not temporally predictable. Fish were housed in pairs, giving us the smallest possible group size so that interactions between animals could be better understood. We found that when prey are spatially and temporally predictable, one animal aggressively guarded the area under which the terrestrial prey would appear, and chased other individuals away. This led to high capture success rates by the aggressor when it shot down the prey item. Under the spatially predictable (but temporally unpredictable) prey presentation regime, aggressive individuals guarded the area under which prey would appear, and prey capture rates were also high. We found that, when prey are spatially predictable (regardless of temporal predictability), aggressive individuals were more likely to shoot down prey and have high rates of capture success, while bystanders rarely shot down prey and were less successful at stealing prey. Bystanders were always non-aggressive and were unable to secure a spot for an extended period of time underneath where prey would appear. Future work will quantify circulating hormones in archer fish and seek a physiological understanding of why shooters are aggressive and bystanders are not.
