Role of sensory mechanisms in predatory feeding behavior of juvenile red drum Sciaenops ocellatus

Abstract

The red drum Sciaenops ocellatus Linnaeus is an exotic aquaculture species in Taiwan. As a carnivore it preys on a variety of food organisms, including fishes and invertebrates. Isolating the sensory mechanisms that govern its predatory behavior would help clarify its feeding habit. The present study focused on predation responses influenced by vision, olfaction and lateral line in captive juvenile red drum. Results showed that the lateral line had themost significant influence on predatory behavior of the fish. Blocking mechanoreception of the lateral line system resulted in complete loss of ability to catch prey. Ablation of olfaction, in contrast, caused a booster effect on the predation rate. Experimental fish with scorched olfactory rosettes showed active predatory behavior. Nearor complete darkness had insignificant influence on the predation rate. When the lateral line system was blocked, the fish could not prey normally, even when vision and olfaction were left intact. It was concluded that mechanoreception plays the primary role and vision the secondary role in predatory behavior of the red drum.