Date of Award


Document Type


Degree Name

Master of Science




The effects of constant photoperiod (14 hours of light) and decreasing photoperiod (13-8 hours of light) on the regressive phase of the ovarian cycle of the lizard Anolis carolinensis were investigated. Changes in body, liver, ovary and oviduct weights were measured and microscopic examinations of several ovarian parameters were made. In both light regimens body and liver weights decreased over the first four weeks of the experiment but both increased at the sixth week. In addition, ovary weight was highly variable but exhibited a decreasing trend and oviduct weight decreased. There were decreases in the number of previtellogonic follicles and in the diameter of the largest previtelogenic follicles in anoles subjected to a decreasing photoperiod. There were no changes in these parameters in anoles kept at a constant photoperiod. On the basis of these data, decreasing photoperiod is proposed to be the environmental cue for regression in Anolis carolinesis

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