A method for directing the displacement of aquatic crustaceans after feeding by utilizing their biological tendency responding to a bright and dark contrast is provided. This method comprises steps to generate the visual effect of this bright and dark contrast at a predetermined place within the water body of culture. Light coming from light emitters directly or from reflection of protrusions and/or painted patterns/figures, and/or filtration of light filters, with the existence of illuminating light, are used for generating visual effect of the bright and dark contrast.
Methods for guiding aquatic crustaceans by utilizing biological tendency responding to visual effect of bright/dark contrast and brightness