COMPOSITION AND DIVERSITY OF CRABS (DECAPODA, BRACHYURA) OF BRAZILIAN NORTHEAST MANGROVE

Crustaceans, Diversity, Taxonomy, Abiotic factors.

Abstract

The composition and species diversity are basic information to understand the processes that involve the balance of the communities and/or ecosystems. The mangrove forest is one of the most threatened tropical ecosystems due to the growth of adjacent cities, logging, overfishing, agricultural plantations and in the light of climate change. Thus, the aim of this study was to describe the composition and diversity of crabs (Crustacea: Brachyura) of mangrove forest of Formoso River, State of Pernambuco, Brazil. For this, we have been collected monthly from March 2009 to April 2010, covering four sampling sites. The temperature of the air, temperature and salinity of the burrows were measured and correlated to the abundance of species. To determine patterns in the structure and composition of the assemblage of brachyuran multivariate analyzes were performed and the calculation of the total diversity indices and for each sampling sites. They recorded 7,544 individual of crabs belonging to 23 species, 15 genera and seven families. Families with higher richness were Ocypodidae and Panopeidae. In relation to the four sampling sites (P1 to P4), the species richness followed the following order (number of species): P4 (18)> P1 (15)> P2 (13)> P3 (08). The higher abundance, in turn, followed the order (number of individuals): P1 (2,242)> P3 (2039)> P2 (1,820)> P4 (1443). Among the species sampled crabs, Leptuca thayeri and Leptuca leptodactyla were the most abundant. Analysis of the Rényi diversity index showed the same hierarchical order registered to richness. The higher diversity occurred in P4, including the higher number of rare species and species more abundant, while the lowest diversity was in P3, with the second place in specimens collected and where two species were dominant. Most tropical mangroves have not been well evaluated for their diversity, there also several species to be described and / or discovered. This study may contribute to the knowledge of taxocenose local crabs, providing subsidies to conservation projects and management of this estuarine area where human action is growing.