Zebra fish help science yet again. The pineal gland in humans secretes melatonin among other hormones.
phys.org
Mind's eye: How fish detect color and brightness with the brain's pineal gland
We see color because photoreceptor cones in our eyes detect light waves corresponding to red, green, and blue, while dimness or brightness is detected by photoreceptor rods. Many non-mammalian vertebrates like fish, however, are known to detect color and brightness with the pineal gland, which...
