Color discrimination conditioning in two octopus Octopus aegina and O-vulgaris. [Japanese]

摘要

In order to investigate the color vision in Octopoda, color discrimination conditioning and transposition tests were done with two octopuses, Octopus aegina and O. vulgaris in tanks. The animals were trained to discriminate by touch between blue (25 mm in diameter, reflectance lambda (max) = 460 nm) and white or light shaded balls (negative balls) for a food reward. The balls were presented simultaneously in front of a shelter wherein each animal resided. After the completion of the conditioning, the negative balls were substituted with ones of different shades of gray (G1 to G5 in the order of reflectance), and transposition tests were done to examine the possibility of darkness-based discrimination.