Development of the Size Selectivity Theory of Angling Gear

在这项研究中，鱼的大小的影响和影响的主要组成部分的钓鱼齿轮的特性进行了调查。建立了这些因素与尺寸选择性之间的关系，发展了斜齿轮的尺寸选择性理论。1）鱼钩进入口腔模型的过程是流体阻力作用的结果。模型中大钩或大饵的最大入水距离大于小钩或小饵。但大钩的进入率低于小钩。2）对于长型弯钩，当弯钩柄部接触模型入口上部时，弯钩最大进入距离发生变化。对于圆形钩，当柄接触入口时，最大进入距离似乎没有变化。3）根据钓鱼试验估算的硬入系数，对给定的鱼体大小，存在一个合适的饵料尺寸。饵粒大小与硬入系数有关。由于不存在线性关系，难以建立数学模型。4）在钩挂机构的随机模型中引入了入距限制，使得该模型能适用于更多的偏角现象。进入距离的限制与口腔、钩和诱饵的大小或形状之间的关系将在未来进行研究。

In this study, the influence of fish size and the influence of the characteristics of the main components of angling gear were investigated. A relation between those factors and size selectivity was found, so the size selectivity theory of angling gear was developed.1) The entering process of a hook into the model of a mouth cavity occurred by fluid resistance. The maximum entering distance of a big hook or a big bait in the model was longer than a small one. But the ratio of entrance of a big hook was lower than for a small one. Considering the ratio of entrance, the total average of the maximum entering distance of the big hook was shorter than for the small one.2) For the long type hook, the maximum entering distance changed when the shank touched the upper part of the entrance of the model. For the round type hook, it did not appear that the maximum entering distance changed when the shank touched the entrance. And this hook had an advantage for hooking because the hook point easily touched the upper inside of the model.3) It was shown that a suitable bait size existed for a given fish size, according to the hard entering coefficient estimated by angling experiments. Bait size was related to the hard entering coefficient. Because there was not a simple relation, such as liner, it was difficoult to construct a mathematical model.4) As the limit of entering distance was introduced in the stochastic model of the hooking mechanism, this model could be fit on many more cases of angling phenomenon. The relation between the limit of the entering distance and size or shape of a mouth cavity, a hook, and a bait will have to be investigated in the future.