Abstract
The effect of DC-pulse electric stimulus on the swimming behavior of larvae of the freshwater mussel Limnoperna fortunei was investigated under flowing water conditions in a pipe. Freshwater mussel larvae were collected for microscopic observation after having been made to pass through an electric field by pumping lake water from a dam through a pipe electrode. Two types of pipe electrode configuration were tested: one with alternating+and-electrodes along the pipe and the other with several+electrodes between two-electrodes. In the case of the latter electrode configuration, 7kV voltage effectively immobilized the larvae and 80% of the larvae were stunned when given an electric stimulus (voltage x total pulse discharge) of approximately 270. Freshwater mussel larvae were effectively stunned with DC-pulse electric stimulus under flowing water conditions. Hence, installation of pipe electrodes upstream of target sites may prove an effective method of protection from mussel fouling by stunning passing larvae. In future studies, the settlement condition of the larvae after passing through the electric field will be investigated as part of our efforts to establish an antifouling method against the freshwater mussel using a DC-pulse electric system.
