返し網付垣網の誘導効果に関する基礎的研究

抄録

Water tank experiments on fish behaviour towards model nets were conducted using tilapia Oreochromis niloticus to compare the leading effects between a straight leader-net and a leader-net with Kaeshi-ami. The difference in leading effects between the two different types was evaluated by the swimming distance along the leader-net and the leading rate of the leader-net. The results showed that the swimming distance along the leader-net with Kaeshi-ami was much longer than that of the straight leader-net. The leading rates of the straight leader-net and leader-net with Kaeshi-ami were 12% and 48%, respectively. Moreover, it was sug-gested that improvements in the construction of Kaeshi-ami can increase its leading effect.