魚の種類による駆集網の駆集効果

スポンサーリンク

概要

• 論文の詳細を見る

• The author has done experiments to see different effects of net on driving fish schools of 5 species using "Driving to one side method". (Refference 1) 2)) Fish used were 2 Carassius auratus Goldfish of total length 6.5cm., 2 Cyprinus carpio Carp (gold variety) of T. L. 4.5cm., 2 Oryzias latipes Japanese Killifish (gold variety) of T. L. 2.0cm., 2 Acheilognathus lanceolata Common Japanese bitterling of T. L. 6.0cm. and 1 Chaenogobius annularis urotaenia Common Goby in fresh water T. L. 4.5cm.. Numerical values were observed in the experiment to drive the fishes from one side of tank to other side at a speed of 10cm. per minute by a frame of width 25cm. and height 10cm., on which white vinyle tubes of 1mm. dia. are vertically stretched at an interval of 2.0cm. each. When the fishes start to move to the other side through the frame, the position of the frame was observed. Size of the tank was 150cm. long, 26cm. wide and 8cm. water depth, but the length was changed to 60, 80, 100, 120 or 150cm. as observing conditions, when drivings were made. They were done 30 times in every case, through Aug. 31 st--Sep. 5 th, 1956, time being 11.00--14.00 and water temperature 21.5--26.0°C.. The observed values are given in Table 1. and those frequency distributions are expressed in Fig. 1., also their mean values with standard deviation are given Table 2. and Fig. 2. Table 3. expresses degree of effect as ratio of frequency to driven fishes till a certain position by repeating 30 times. Table 4. also expresses degree of driving effect as percentages on the average driven value of distances in cm. by the tank length at the time when the driving started. Summarizing his consideration, the driving effect is less under the starting length at 60cm., and is much under the length over 80cm. There is a remarkable difference in driving effects among each fish which, in the case of Goldfish and Carp are comparatively hard, and in the case of Killifish, Bitterling and the goby are very easy.

• 社団法人 日本水産学会の論文

著者

• 草下 孝也

  東京大学農学部

関連論文

• 垂直網の網目と魚体の大きさとの関係
• 傾斜沈垣網の効果について
• 彩色した沈垣網の効果について
• 狭い場所から開放されたときの魚群の行動
• 魚の種類による駆集網の駆集効果
• 駆集網に関する二つの実験方法による網目の大きさ
• 駆集網の色彩の濃さの効果について

スポンサーリンク