The impacts of temperature on feeding behaviors in tautog (Family: Labridae; Tautoga onitis)

Abstract

Changing environmental temperatures can impact ectotherm behavior in a number of ways, many of which can be crucial for survival. Prey capture behaviors have been shown to change with changing temperature. While temperature effects are clearly important to fishes that rely on rapid buccal expansion to create suction, less is known regarding temperature impacts on fishes that rely on biting. To understand this better, we exposed tautog (Tautoga onitis) to 10, 25, and 28 °C and recorded their feeding behaviors on sandworms and Asian shore crabs. When feeding on crabs, the only kinematic variable that differed with temperature was the time it took to capture prey. When feeding on sandworms, the only variable that differed was the velocity of gape expansion. Gape opening velocity and time to prey capture were faster when feeding on sandworms compared to crabs. Despite a 15 °C difference in our treatments, increasing temperature had a minimal impact on feeding performance. However, prey type appeared to cause a behavioral shift from suction feeding (sandworm) to biting (crab). This modulation of behavior is remarkable given the anatomical specializations tautog have to favor biting. Interestingly, the tautog’s realized trophic niche, as confirmed with gut content studies, does not match their hypothesized trophic niche based on feeding performance metrics described here.