幼稚魚が流れ藻に伴う機構についての実験的研究-II

照度の影響についての実験

抄録

Regarding the gathering behavior of juvenile fishes under drifting seaweeds, the effect of reduction in light intensity was studied through experiments with a variable light aquarium (Fig. 1).
Most of the juvenile fishes used in the experiments gathered in the light part of the aquarium rather than in the dark part. None of the fish species tested gathered positively in the dark part.
Sensitivities to changes in light intensity vary specifically, and Rudarius encodes are extremely sensitive (Table 2). It seems that those fishes living in a closer spatial relation with drifting seaweeds are less sensitive.
Factors other than the reduction in light intensity must play more important roles in causing the gathering of juvenile fishes under drifting seaweeds. Further studies into the factors are necessary.