漁網の色に関する研究-IV : 照度変化が魚群の行動に及ぼす影響について

スポンサーリンク

概要

論文の詳細を見る
Chief results of the present observations are summarized as follows: 1) A school of fish (Salmo gairdnerii irideus (GIBBONS)) meeting with a coloured net behaves differently as the illumination changes. Where-as it is the wave length of the light reflected by the net what is influential in the day time, both the kind and the depth of colour of the net affect the fish behaviour in twilight. 2) In the light of day time fish passage through a coloured net seems to be independent of the maximum distance at which, the net is visible in water. But in twilight the more readily fishes become entangled in a net, the shorter the range of vision for the net. 3) No particular relationship seems to prevail between the brightness of the reflected light on a coloured net and the passage of a fish school through the net. In twilight, however, where fish enmeshing was observed instead of fish passage using a net of smaller sized mesh, it may be said that with nets of the same kind of colour, fish enmeshing takes place the more frequently in the darker colour of the net. 4) As for a coloured net in twilight there holds a good parallelism between the invisibility of the net to the naked eye and the tendency of fish to be entangled in the net. 5) Barring effect of a coloured net against fish passage is greater in the day time than in twilight.

著者

関連論文

もっと見る

スポンサーリンク