Spectral sensitivity and color vision of fish as indicated by S-potential

Abstract

1. 1. Black porgy, chidai and neko shark seem to be color blind, since no chromatic type of S-potential was recorded in their retinas. 2. 2. From the presence of the chromatic responses in the retina, the ability to discriminate colors is thought to exist in mullet, carp, goldfish, suzuki, bluegill, yellow-tail and sting ray, and is especially well developed in the first three. 3. 3. A luminosity response, having a maximum between 584 and 612 mμ, was only found in carp, goldfish, bluegill and mullet. The high percentage of the occurrence of this response in these fishes suggests that they are most sensitive to the wavelengths around 600 mμ, which are also the prevailing wavelengths in their usual habitats. 4. 4. A shift of the maximum L-response to shorter wavelengths was observed in marine fishes such as suzuki, yellow-tail, sting ray, black porgy, chidai and neko shark. This is explained in terms of the adaptation to the environment where light of shorter wavelengths prevails. 5. 5. The S-potential method is suggested as a useful way to investigate color vision and spectral sensitivity of the fishes, especially those which are not suitable for training or behavioral experiments.