About the sense organs of crayfish

Despite the fact that crayfish (Astacus fluviatilis L, etc.) are very widespread and well-known animals, and in zoological laboratories they are favorite objects for studying the type of crustaceans, the psychophysiology of their sense organs is still in its infancy. Until now, they argue whether the crayfish have a hearing or not, whether they are capable of a sense of taste, whether they have a sense of smell, whether they distinguish colors, whether they can see words in our usual sense, etc. or these animals, only reflex acts are possible, automatic phototaxis, ototaxis, chemotaxis, rheotropism, negative or positive, etc., and the presence of the psyche is completely excluded. Difficult for the decision has to be considered the question of chemotaxis, as it eliminates the very separation of understanding of taste and smell. It is also difficult to differentiate the auditory response from such to the vibration of water, which is inevitably accompanied by sounds. One of the essential difficulties in resolving these, as well as other similar questions, is that the crayfish is water; have to be considered with somewhat different conditions for physical and chemical influences than on land.