Aquatic insects exhibit many respiratory adaptations that allow them to survive the low oxygen conditions of their environment. Ethological adaptations often free insects from the oxygen constraints of water by allowing them to rely heavily or entirely on atmospheric oxygen. 12 male and 12 female Abedus herberti individuals were observed at different depths and their respiratory behaviors described. Two respiratory behaviors were observed, gaping and fanning. Gaping occurs when the bug depresses the abdomen and exposes the subalar air store to the water. Fanning usually occurs after a period of gaping, and consists of repeatedly bringing the abdomen into contact with the wings and depressing it again in a rhythmic fashion. There was no significant difference in the gaping or fanning behaviors between males and females, but the frequency of gaping and fanning behaviors, time spent performing both behaviors, and the rate of fanning were all positively associated with water depth. These behaviors apparently increase the submersion time of the bugs by promoting gas exchange with the water and ventilation, thus increasing the efficiency of the subalar air store. A. herberti are extremely buoyant insects, so an increased submersion time should decrease the cost of submersion by decreasing the number of trips to the surface necessary to support respiration. This, in turn, increases the amount of time they can devote to capturing food and decreases the likelihood of predation at the surface.