Role of sensory mechanisms in predatory feeding behaviorof juvenile red drum Sciaenops ocellatus
The red drum Sciaenops ocellatus Linnaeus is an exoticaquaculture species in Taiwan. As a carnivore it preys on a varietyof food organisms, including fishes and invertebrates. Isolatingthe sensory mechanisms that govern its predatory behavior wouldhelp clarify its feeding habit. The present study focused on predationresponses influenced by vision, olfaction and lateral line in captivejuvenile red drum. Results showed that the lateral line had themost significant influence on predatory behavior of the fish. Blockingmechanoreception of the lateral line system resulted in completeloss of ability to catch prey. Ablation of olfaction, in contrast,caused a booster effect on the predation rate. Experimental fishwith scorched olfactory rosettes showed active predatory behavior. Nearor complete darkness had insignificant influence on the predationrate. When the lateral line system was blocked, the fish could notprey normally, even when vision and olfaction were left intact. Itwas concluded that mechanoreception plays the primary role and visionthe secondary role in predatory behavior of the red drum.