Distribution of populations of broad-snouted caiman (Caiman latirostris, Daudin 1802, Alligatoridae) in the São Francisco River basin, Brazil

We surveyed populations of the broad-snouted caiman, Caiman latirostris, throughout the São Francisco River basin, from Três Marias reservoir, State of Minas Gerais, to the river delta, at the boarder of Sergipe and Alagoas states. We registered the occurrence of crocodilians in 61% of all surveyed localities (n = 64), in which the presence of C. latirostris was confirmed in 44% of the surveyed sites. Caimans occurred in both lentic and lotic habitats, although there was a preference for small dams, oxbow lakes and wetlands. Despite the hunting pressure and human impact on natural habitats, our results indicate that the populations of C. latirostris in the São Francisco basin are not fragmented

Genetic Diversity of New World Crocodilians

Genetic diversity is one of the most important attributes of any population; it is defined as the variation in the amount of genetic information within and among individuals of a population, species, assemblage, or community. It can be expressed as differences between individuals at different levels, such as morphological features, structure and chromosomal number, and polymorphisms of sequences of DNA or proteins. An assessment of genetic diversity is fundamental to population genetic studies and has extremely important applications in conservation biology and the development of management and sustainable use plans. This chapter discusses the main indices that allow analyzing genetic variability and population structure of New World crocodilian populations, the methodologies used to estimate these indices, and the principal population genetic data available for these species. The effective population size concept is also discussed, a fundamental parameter in the study of principally those crocodile populations that have been drastically reduced in size and/or suffered fragmentation of their environments.Fil: Amavet, Patricia Susana. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Barban Zucoloto, Rodrigo. Universidade Federal da Bahia; BrasilFil: Hrbek, Tomas. Universidad Federal del Amazonas.; BrasilFil: Pires Farias, Izeni. Universidad Federal del Amazonas.; Brasi