[Functional structure of the feeding behavior of the crayfish Astacus leptodactylus]

Analysis of the motor component in feeding behaviour of the crayfish enabled to differentiate it into separate fragments with respect to the targets which are reached due to realization of each of these fragments. It is suggested that separate fragments are realized by some functional blocks which are activated from their own receptive zones by trigger mechanisms. With changing the coordinates of food stimulus the whole structure of the behaviour also changes due to the inclusion of additional fragments (locomotions, rearrangement of postures, activation of the claw extremities, etc.). Since this rearrangement favours the animal in reaching its final target, it may be considered as adaptive one.