Refractoriness in Female Lizard Reproduction: A Probable Circannual Clock
HECTOR S. CUELLAR 1 and
ORLANDO CUELLAR 2
1 Department of Neurobiology and Anatomy, University of Texas Medical School, Post Office Box 20708, Houston 77025
2 Department of Biology, University of Utah, Salt Lake City 84112
Postreproductive Cnemidophorus uniparens maintained under free-running conditions of constant darkness for 7 months became reproductive at the same time as controls exposed to a long photoperiod. This lizard exhibits a pause in reproductive activity (refractory period) commencing in late summer in nature and terminating in mid-December in captivity. Both groups terminated refractoriness and started reproducing simultaneously in December despite maintenance of the experimental group in darkness since September. These results confirm the hypothesis that the refractory period in this lizard is under endogenous control.
Submitted on January 21, 1977
Revised on March 29, 1977
