Meeting Abstract
Fish sense water flow with two types of receptor in the lateral line system. Although neurophysiological and biomechanical studies have demonstrated how these types differ in their sensitivity to flow, it remains unclear what roles these two submodalities play in behavior. We studied how the lateral line permits foraging in the dark in juvenile and adult zebrafish (Danio rerio). The lateral line of this species is similar to a broad diversity of fishes because it includes only superficial neuromasts in juveniles and then develops canal neuromasts by the adult stage. We learned that fish at both stages of growth strike at a vibrating sphere and this behavior ceased if the lateral was compromised by exposure to neomycin sulfate. Juveniles exhibited the greatest probability of striking at the sphere when it was oscillating at a frequency between 28 and 60 Hz. Adults exhibited similar sensitivity, but were additionally responsive to higher frequencies, up to the 100 Hz permitted by our experimental setup. Therefore, changes in the lateral line permit zebrafish to respond to higher frequency signals as they grow. This suggests that the development of canal neuromasts extends the trophic niche available to a fish as it grows by detecting a more broad range of flow stimuli.
