The morphology and density distribution of the cone photoreceptor in the retina of the atlanta stingray, dasyatis sabina
A histological analysis of the retina of the stingray, Dasyatis sabina, revealed the presence of two distinct photoreceptor morphologies. Based upon morphological evidence and literature descriptions it was decided that the two morphotypes represented the rod and the cone photoreceptor. By performing differential counts in multiple regions and expressing cones as a percent of the total number of photoreceptors present, it was possible to determine the cone density through out the retina. Density varied with the location of the retina at which the count had been made. The cone distribution followed two progressive patterns. The density of cones would decrease as ~aunts were taken from the optic disc to the ora serrata and, in those sections which were taken from the rostral and caudal quadrants, a difference in cone density was determined between regions from the same section of tissue. ANOVA testing of these differences determined them to be significant. The pattern of cone distribution was also found to be consistent in all ages and in both genders of this species.
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Laird, Robert J.
Master of Science (M.S.)
College of Arts and Sciences
Length of Campus-only Access
Masters Thesis (Open Access)
Arts and Sciences -- Dissertations, Academic; Dissertations, Academic -- Arts and Sciences
Logiudice, Francis Thomas, "The morphology and density distribution of the cone photoreceptor in the retina of the atlanta stingray, dasyatis sabina" (1990). Retrospective Theses and Dissertations. 4029.