Abstract
A stochastic model on the hooking mechanism representing the capture probability of fish which bit on a hook was made. It was assumed that a fish could not remove a hook once a hook had stuck. Notice was taken of hook movement in the mouth cavity of a fish, so that the difficulty in a hook entering the mouth cavity wasshown by the hard entering coefficient, which indicated the possibility of stop of the inward movement of the hook, and the ease of hooking was shown by the hooking coefficient, which indicated the possibility of hooking for the outward movement of the hook. The stop probability of the inward movement of the hook and the hooking probability were expressed by using these coefficients. The capture probability was derived from these probabilities. The model fitted well with observations from experimental pole-and-line fishing. Consequently, the hard entering coefficient and the hooking coefficient could be represented by functions which consist of two variables, hook width and total length of fish.
