All organisms are limited in the amount of energy they can spend, and therefore an increased spending in one function results in decrease in spending in another, creating an energetic trade-off. Androgens are known to increase signal size in male weakly electric fish, and a larger signal size requires more power and therefore more energy. I investigated if androgens act as a regulator for an energetic trade-off between signaling and cellular metabolism in male Brachyhypopomus gauderio. I measured the male’s oxygen consumption in a respirometry chamber under varying pharmacological challenges to partition the energy budget. Then I implanted the fish with 5α- dihydrotesosterone (DHT) and repeated the respirometry and pharmacological trials. I found that with elevated DHT levels males exert more power per signal and consume more oxygen for communication and less for standard metabolic functions. This research is the first to demonstrate an energetic trade-off between signaling and metabolism in electric fish.
