Dinâmica e conservação de peixes anuais (cyprinodontiformes: rivulidae) no parque nacional da Lagoa do Peixe

Abstract

Annual fish includes a diverse group of small fishes of the order Cyprinodontiformes, divided into two taxonomic families, and distributed in Africa and the Americas. The life cycle of these species is closely related to the temporal dynamics of temporary wetlands. The characteristic of their life cycle makes the annual fish excellent biological models for laboratory studies and development of ecological theories. In South America, this group is represented by the family Rivulidae, and most of its species are found in Brazil. In Rio Grande do Sul State (RS) are found the genera Austrolebias and Cynopoecilus, and highly representative of their species demonstrate the importance of this region as a center of endemism of this group. The combination of its specialized life cycle, with their small sizes, restricted range, limited dispersal ability, and the widespread destruction of wetlands make numerous species of the family Rivulidae are threatened of extinction. Despite their high productivity and biological diversity, wetlands are one of the most threatened and vulnerable ecosystems. In Rio Grande do Sul, 90% of these areas have been lost due to agriculture and urbanization. In this sense Conservation Units can be a key to the conservation of these ecosystems and the annual fish endemic and threatened. However the total protected area is insufficient to maintain its high diversity and records of annual fish in protected areas are scarce. The lack of ecological information on annual fish populations in protected areas is one of the key constraints to support the adoption of conservation strategies and management plans for the species of this group. Accordingly, we analyze the variation in abundance and body size of Austrolebias minuano and Cynopoecilus fulgens, two species endemic to the Coastal Plain of Rio Grande do Sul, in temporary wetlands of the Lagoa do Peixe National Park, an important conservation area, considered a Ramsar site. These species have no record in any other protected area and our study showed that they are found in higher densities at the beginning of its life cycle, when they have small sizes. The endangered species, A. minuano showed a low density, demonstrating the importance of specific plans for their conservation.