Reproductive traits of two sympatric viviparous skinks (Mabuya macrorhyncha and Mabuya agilis) in a Brazilian restinga habitat

The reproductive cycles, fat body cycles and some life-history traits of th e sympatric viviparous skinks Mabuya macrorhyncha and M. agilis were compar ed in a seasonal "restinga" habitat of south-eastern Brazil. Both male and female reproductive and fat body cycles are very similar between species, w ith gestation lasting 9-12 months and parturition occurring during the earl y wet season. Clutch size of M. macrorhyncha was smaller than that of M. ag ilis. Females mature at a larger size in M. macrorhyncha than in M. agilis, but males of both species appear to mature at similar sizes. In both speci es, females are larger than males, but the latter have proportionately larg er heads. Reproductive traits of M. agilis are typical of Neotropical Mabuy a, but those of M. macrorhyncha have some peculiarities, one of which (smal l clutch size) is believed to result from constraints imposed by its morpho logical adaptation (i.e. relatively flattened body plan) to bromelicolous h abits.