Sexual dimorphism in size and shape in the viviparous lizard Abronia taeniata (Squamata: Anguidae) in central Mexico

Abstract

AbstractIn the present study, we analyse sexual dimorphism in size and shape of morphological attributes in a population of Abronia taeniata in central Mexico. The variables analysed were snout–vent length (SVL), head length (HL), head width (HW), head height (HH), tibia length (TL) and femur length (FL). In the size attributes, males and females had similar SVL, and males were larger in the rest of the variables analysed (HL, HW, HH and FL), except TL. In the case of shape, the females had larger dimensions in the relative logSVL variable, and the males were larger in the relative logHL, relative logHW and relative logHH variables. The variables relative logFL and relative logTL showed no sexual shape dimorphism. The similarity in the sizes and the sexual dimorphism between sexes in attributes of the head and extremities are explained by the hypothesis of sexual selection directed to the structures of the head in males, and in the case of shape in females, to the fecundity hypothesis. Comparative studies that analyse a greater number of morphological variables are necessary to determine the factors that promote the different patterns of sexual dimorphism in the group.