Abstract
The sexual dimorphism in size, morphology and color of the lizard Liolaemus occipitalis Boulenger, 1885 was studied. Thirty-two adult males and twenty-eight adult females were sampled from a population in the Jardim do Éden beach, near Tramandaí, Rio Grande do Sul, Brazil. Size related sexual dimorphism occurred in all compared body dimensions. The largest female was 59.6 mm in snout-vent length, and the largest male was 69.3 mm. Males and females also presented differences in ventral and dorsal color pattern, and in the presence of pre-cloacal pores. The results suggest that, in Liolaemus occipitalis, sexual dimorphism in size is determined by sexual selection, competition between males and by the high energetic cost for females a few months after hatching.
Highlights
Sexual dimorphism can be observed in morphology, color pattern and behavior
According to CAROTHERS (1984), sexual dimorphism can be the result of sexual selection as a mechanism for reducing competition for food between males and females
Numerous studies on insectivorous lizards have shown that size differences between sexes are related to segregation of food resources (RAND, 1967; SELANDER, 1972; SCHOENER, 1977; STAMPS, 1977a)
Summary
Sexual dimorphism can be observed in morphology, color pattern and behavior. Some authors discuss the evolution of size related sexual dimorphism in birds (SELANDER, 1972), primates (CROOK, 1972), amphibians (WOOLBRIGHT, 1983), insectivorous lizards (STAMPS, 1983), omnivorous lizards (ROCHA, 1996) and herbivorous lizards (CAROTHERS, 1984).According to CAROTHERS (1984), sexual dimorphism is determined by three factors: female reproductive strategy (TINKLE et al, 1970), sexual selection (CAROTHERS, 1984) and competition for food resources (SCHOENER, 1967). ANDERSON & VITT (1990) suggest that the causes of sexual dimorphism in size could be related to several factors: competition between males; differential mortality between sexes due to differences in longevity; larger amount of energy allocated by females for reproduction; males are more active because they need to search for females and present a larger predation risk. ANDERSON & VITT (1990) suggest that the causes of sexual dimorphism in size could be related to several factors: competition between males; differential mortality between sexes due to differences in longevity; larger amount of energy allocated by females for reproduction; males are more active because they need to search for females and present a larger predation risk. These authors suggest that sexual dimorphism could be connected to the feeding strategy which is directly related to phylogenetic characteristics of the family. When a larger body size is favored in male choice by females, selection tends to promote an increase in male size relative to female size (VITT & COOPER, 1985)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
