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Behavioral Physiology of Fish in Capturing Process of Mid-Water Trawl

中层拖网捕捞过程中鱼类的行为生理

基本信息

批准号：
01460233
负责人：
ARIMOTO Takafumi
金额：
$ 2.69万
依托单位：
Tokyo University of Fisheries
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01460233/
关键词：
Mid-water trawl Capturing process Walleye pollock Visual physiology Swimming behaviour Fishing Gear designing Electrophysiology Telemetry 運動生理疲労

项目摘要

The research project deals with the behavioral physiology of target species in relation ot the gear geometry in the capturing process of mid-water trawl fishing, consisted of three main themes ; the analysis of gear geometry and control, the reaction of targeted fish towards the gear, as well as the visual physiology and the swimming physiology of walleye pollock, Theragra chalcogramma.On board the northern off-shore trawlers, the acoustic telemetry observation was conducted to understand the static and dynamic geometry or net gear ; such as the depth, height and width of net mouth and the otterdoors distance. These factors of net shape during towing were corresponded to the Lowing speed and warp length. From the acoustic results, the deck working cycle for the net shooting and hauling procedures was analyzed and discussed.Concerning the visual physiology of walleye polloock, on-board sampling of eyeball was conducted for the purpose to identify the retina adaptation in relation to the … More towing depth and time of day. The microscopic examination-snowed that the retina was not fully light-adapted Pven with the daytime sampling in the fishing ground of 200m or deeper. It indicates the incapability of colour discrimination but the higher sensitivity to the weak light intensity. Besides, with the data of lens size arid visual cell density on the retina, the visual acuity was determined so as to estimate the maximum sighting distance accordinig to the size of fish in the ideal condition. T. n order to determine Lhe light sedsitivity of walleye pollock, the electrophysiological experiments were also conducted with the variation of the wave-length, durationl/frequencies and intensity of light, stimuli, in comparison between light and dark adaptation of retina under the various lighting conditions.Another important factor of behavioral physiology is the swimming performance of fish as the muscle activity in relation to the reaction of fish toward the towed gear. On-board and laboratory experiments was conducted to measure the muscle contraction time from the view point of the scale and temperature effect. From the results, the maximum tail beat frequency was determined. In addition, the swimming behaviour in tank was video-recorded to obtain the data for the stride length per I tail beat. As the final, the maximum swimming speed was estimated with the special reference of the temperature dependence. The results of temperature effect on muscle contraction time indicate better swimming performance of fish at higher temperatures. This implies that a relatively higher towing speed is required in mid-water trawling in which water temperature is relatively high. Less

本研究项目涉及中水拖网捕捞过程中与渔具几何形状有关的目标物种的行为生理学，包括三个主题；分析渔具的几何形状和控制，目标鱼对渔具的反应，以及狭鳕（Theragra chalcogramma）的视觉生理和游泳生理。在北方近海拖网渔船上，进行了声学遥测观测，了解网渔具的静、动几何形状；如网口的深度、高度和宽度与水獭门的距离。拖曳过程中网形的影响因素与拖曳速度和经纱长度有关。从声学结果出发，分析和讨论了放网和拖网过程的甲板工作周期。关于青鳉鱼的视觉生理，为了确定视网膜对拖曳深度和时间的适应性，对其眼球进行了船上采样。显微镜检查显示，即使在200米或更深的渔场进行白天采样，视网膜也不完全适应光线。这表明它不能辨色，但对弱光强度有较高的灵敏度。此外，根据晶状体尺寸和视网膜上的视细胞密度数据，确定视敏度，以便在理想状态下根据鱼的大小估算最大视距。为了确定狭鳕的光敏感性，我们还进行了光刺激波长、持续时间/频率和强度变化的电生理实验，比较了不同光照条件下视网膜的光适应和暗适应。行为生理学的另一个重要因素是鱼的游泳表现，因为肌肉活动与鱼对拖曳装置的反应有关。从尺度和温度效应的角度对肌肉收缩时间进行了测量。根据实验结果，确定了最大尾拍频率。此外，还对池中的游动行为进行了视频记录，以获得每尾拍的步幅数据。最后，在考虑温度依赖性的情况下，对最大游泳速度进行了估计。温度对肌肉收缩时间的影响结果表明，温度越高，鱼类的游泳性能越好。这意味着在水温较高的中水拖网作业中，需要较高的拖网速度。少