Ganglion Cell Topography and Retinal Resolution in the Bottlenose Dolphin Tursiops truncatus at an Early Stage of Postnatal Development

Eye sizes and retinal organization were studied in newborn and adult bottlenose dolphins Tursiops truncatus. In the newborn animals, the eye optics and retinal organization were completely formed, including the presence of two zones of increased concentration of retinal ganglion cells. Adult animals had larger eye sizes as compared to the newborn ones, larger retinal thickness, larger retinal area, and more ganglion cells. The peak ganglion cell density in the newborn animals was higher than that in the adult ones; however, the retinal resolution differed insignificantly. It is shown that the postnatal development does not principally modify the eye organization but results in a quantitative shift of the main parameters.