Accession Number : AD0619235

Title :   EXPERIMENTAL ANALYSIS OF THE VISUAL SYSTEM OF THE FOUR-EYED FISH ANABLEPS MICROLEPIS,

Corporate Author : CALIFORNIA UNIV LOS ANGELES

Personal Author(s) : Schwassmann,Horst O. ; Kruger,Lawrence

Report Date : 15 JAN 1965

Pagination or Media Count : 15

Abstract : Specialization of optical structures in the Anableps eye allows simultaneous vision in air and water in two different optical axes. The tectal projection of the aerial and aquatic visual field was mapped by electrophysiological methods and was found to be similar to that in freshwater fishes, except for an area above the waterline with greatly enlarged tectal magnification in Anableps, correlated with increased ganglion cell density in the corresponding retinal region. Size threshold for movement perception is lower in the aerial visual field than in the aquatic field and seems correlated with higher cone density in the ventral retina. Finger-like iris flaps between the two pupillary apertures prevent double-image formation due to light refraction at the waterline. (Author)

Descriptors :   (*FISHES, VISION), (*VISION, FISHES), EYE, RETINA, VISUAL ACUITY, NERVE CELLS, GANGLIA, THRESHOLDS(PHYSIOLOGY), ADAPTATION(PHYSIOLOGY), MORPHOLOGY(BIOLOGY), OPTICAL IMAGES, LIGHT, REFRACTION

Distribution Statement : APPROVED FOR PUBLIC RELEASE