Development of color vision in goldfish: selective delayed maturation of blue vision

Wavelength discriminations in juvenile and adult goldfish were measured among three sensitivity maxima (450, 525 and 625 nm) of goldfish cone photoreceptors using a "go/no-go" (electroshock avoidance) task. The ability of juveniles to discriminate was significantly poorer in 450/525 nm and 450/625 nm discriminations than that of adults. While only a few juveniles acquired clear discriminative responses, there was a greater proportion of adults. In contrast to those discriminations, the ability of juveniles to discriminate between 525 and 625 nm was similar to that of adults. These results suggest that juveniles, in contrast to adults, have selective delayed development of the blue-sensitive mechanism. Some possible explanations for the poor blue discrimination of juveniles are proposed.