Reproduction and Sexual Dimorphism in the Tropical Teiid Lizard Cnemidophorus ocellifer

Abstract

The reproductive cycles of male and female Cnemidophorus ocellifer were studied from March 1977-Feb. 1978 in a caatinga habitat of northeast Brazil. Females with oviductal eggs occurred in every month except June. A large proportion of females contained oviductal eggs and vitellogenic follicles suggesting production of multiple clutches. The seasonal distribution of reproductive state of females suggests three clutches may be produced annually. Clutch size varied from 1-5 with a mean of 2.67. Larger females tended to produce larger clutches than smaller females. Males also were reproductive throughout the year, with enlarged testes and convoluted epididymides. There was no apparent association between reproduction and wet-dry seasonality as reported in certain other lizard species at the same locality. Mass of abdominal fat bodies in males and females, however, was associated with seasonality in rainfall. Fat bodies were largest during the wet season and smallest during the dry season. Apparent sexual dimorphism in size was evident with males larger than females. Sexual dimorphism in head size was pronounced. Observations on social behavior suggest that sexual dimorphism results from sexual selection.