In diurnal animals, the chromosomes in the nucleus are densest around the edges, which means that any absorbed light is scattered around the edges. In nocturnal animals, the densest material is in the center of the nucleus, effectively focusing all of the available light in one area. One can only guess at what nocturnal animals see. Most nocturnal animals also have a highly developed sense of hearing, touch e. Many animals designed for night vision have only rod cells in their retinas, and lack cone cells entirely.
What disadvantages would such an arrangement have for seeing in daylight? The creature was standing in the dark beneath a towering pine. Wonderful piece. Thank you! To ensure a respectful dialogue, please refrain from posting content that is unlawful, harassing, discriminatory, libelous, obscene, or inflammatory. Northern Woodlands assumes no responsibility or liability arising from forum postings and reserves the right to edit all postings. Thanks for joining the discussion.
Cones work in bright light and register detail, while rods work in low light, detecting motion and basic visual information. It is the rods that become highly specialized in nocturnal animals. In fact, many bats, nocturnal snakes and lizards have no cones at all, while other nocturnal animals have just a few.
Tapetum Many nocturnal eyes are equipped with a feature designed to amplify the amount of light that reaches the retina. Called a tapetum, this mirror-like membrane reflects light that has already passed through the retina back through the retina a second time, giving the light another chance to strike the light-sensitive rods.
Whatever light is not absorbed on this return trip passes out of the eye the same way it came in—through the pupil. The presence of the tapetum can be observed at night when a pair of glowing eyes reflects back a flashlight or some other light source. Interestingly, different animals have different color tapeta, a fact that can aid in nighttime animal identification.
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