Macroecologia das comunidades de metazoários parasitos de Cichla kelberi e C. piquiti (Osteichthyes, Cichlidae).

Abstract

The macroecology search geographical patterns of distribution and abundance of a species in large-scale, and represents one of the central themes of biogeography. The parasites communities have a fundamental role in the models for studies of biodiversity and biogeography, two ecosystems may differ in the composition of parasitic fauna. According to environmental conditions, life cycles and the availability of intermediate hosts in each ecosystem may show variations in prevalence and abundance of infection/infestation by a given parasite. Biological invasions have increased in recent years representing a threat to global biodiversity. This study had two objectives: test the hypothesis that extrinsic factors (e.g. aquatic ecosystem) is the key factor that modulates the communities of parasites in populations of Cichla kelberi and C. piquiti from six Brazilian aquatic ecosystems, using their parasites as predictor variables and discriminant of host populations; and test the hypothesis of decreasing similarity among infracommunities and component communities of parasites of C. kelberi and C. piquiti with increasing geographical distance. The first chapter notes that the component community of parasites of C. kelberi is less diverse and abundant than C. piquiti, and those communities components of both host species were mainly influenced by ectoparasites. The canonical discriminant analysis and correspondence analysis showed that the parasitic abundance and prevalence in individuals of C. kelberi and C. piquiti is a good indicator to discriminate and correspond host populations. Thus, the component communities of parasites in host populations of areas biogeographically distinct show infection levels, life cycle, composition, richness and dominance of species characteristic of the environment in which it placed. These results may be related to stability of population and environmental and, mainly, the anthropogenic actions of introductions of peacock bass in these ecosystems. The subsequent chapter refuted the hypothesis of the decline of similarity with increasing geographical distance to the parasite communities of C. kelberi and C. piquiti because it is introduced host species that change and suffer different ecological processes from native species, suggesting that the phenomenon of the decline of similarity is not universal as viewed in previous studies, taking place a break of dispersion limits imposed by geographical barriers to introduced species due to human activities.