REPRODUCTION AND GROWTH OF THE OPOSSUM MONODELPHIS-DOMESTICA (MAMMALIA, DIDELPHIDAE) IN NORTHEASTERN BRAZIL

The reproduction and growth of the grey short-tailed opossum, Monodelphis domestica were studied at seven localities in semi-arid northeastern Brazil. Data were gathered from 1031 specimens stored in the Museu Nacional do Rio de Janeiro. The data allowed us to determine the degree of sexual dimorphism, number of embryos, the relationship between post-partum development and reproduction, and the breeding season. Adult M. domestica have marked sexual dimorphism, but juveniles do not. Females reduce growth when they attain puberty and produce their first litter. However, growth of males is not interrupted during their first reproductive season. This may reflect differences in reproductive investment between sexes. The mean number of embryos was 7.9 with a range from 2 to 16. The species reproduces seasonally probably in response to variation in day length.232455156