Development of a bivalve predation detector by eagle ray (Aetobatus flagellum) and other living organisms

Abstract

The purpose of this research is to develop a bivalve predation detector. Clam predators like eagle ray (Aetobatus flagellum) crash clam shell to eat it. Firstly, we reveal the fact that eagle ray creates shot sounds when it eats short-necked clams through a sea water tank experiment. Secondly we make computer programs to count the pulse number included in a shot. The sounds created by the ray tend to include several pulses in a shot, whereas the sounds created by the crab tend to include only one or two pulses. A shot including more than three pulses can be the proof of the predation of the ray with 48% accuracy. This technique can be utilized for a ray migration monitoring system and/or a trigger device for a predation prevention system such as electric shocker.