Meeting Abstract

38.3  Saturday, Jan. 5  Sensory switching in sharks: the role of multimodal stimuli in prey tracking and capture GARDINER, JM*; ATEMA, J; HUETER, RE; MOTTA, PJ; Mote Marine Laboratory; Boston University; Mote Marine Laboratory; University of South Florida

Hunting involves a sequence of steps with increasing sensory information as the distance between predator and prey decreases. Little is known about multimodal aspects of hunting underwater, where prey can be visible, emit hydrodynamic disturbances, odors, sounds and/or electric fields. We investigated three shark species from different ecological niches: nurse sharks, bonnetheads, and blacktip sharks. We blocked olfaction, vision, the lateral line, and electroreception, alone and in combination, to elucidate their complementary and alternative roles in feeding. Interspecific similarities and differences exist among sharks in terms of which senses they focus on for particular phases of feeding behavior. In most cases, multiple senses can be used for the same behavioral task, allowing sharks to switch to alternative sensory modalities to successfully capture prey. Under our experimental conditions, nurse sharks rely on olfaction for detection and track using olfaction combined with vision, the lateral line, or touch. They orient to prey using the lateral line, vision, or electroreception, but will not strike without olfaction. Capture requires electroreception or touch. Bonnetheads normally use olfaction to detect prey, olfaction combined with vision or the lateral line to track, vision to line up a strike, and electroreception for capture. They can detect, orient, and strike visually in the absence of olfactory cues. Blacktip sharks also detect prey using olfaction or vision, and track using olfaction combined with vision or the lateral line. Long-distance orientation and striking is visually mediated but in the absence of vision, close-range orientation and striking can be lateral line-mediated. Capture requires electroreception or touch. Collectively, these results reveal species-specific sensory hierarchies for shark feeding behavior.