Effect to age on the geographic variation in morphometric traits among populations of Boana cordobae (Anura: Hylidae)

Abstract

The morphometric variation of body size is an important topic of the natural history of the species which has been received particular interest. In this study, we estimated differences in body size and age structure of six populations of Boana cordobae living at different altitudes, 808-2 310 m.a.s.l. in Córdoba and San Luis provinces (Argentina). We measured 15 morphometric variables and used skeletochronology to age determination of 79 individuals. Morphometric variables showed significant differences between sexes, being females larger than males, even when the effect of age was taken into account. We found a significant relationship between age and most of the morphometric variables. When removing the effects of age, we found significant inter-population differences in body size. Males from the high-elevation populations were larger than individuals from low-elevation populations. These results suggest that a difference in age structure between populations is a main factor for the geographic variation in body size of this species.