Diversidade e heterogeneidade espacial da meiofauna: com ênfase em Nematoda em ecossistemas recifais de Alagoas - Brasil

Abstract

The meiofauna has an important role in reef ecosystems, helping in local primary production and serving as food for juvenile fish and small crustaceans. Studies conducted to nematofauna and meiofauna in the coral reefs are scarce and because of this there is still no sampling standard methodology. This paper is divided into two chapters that had the purpose of identifying the most effective methodology for sampling meiofauna of the hard bottom of the reefs (chap.I) and characterize the Nematoda community of the Paripueira reef ecosystem (chap.II). In the reefs of the Pontal do Pebabeach, samples were carried out in two periods, August 2010 and August 2011, in three areas. Two sampling methods were tested: suction pump (with three different times of suction: I = 20s = 1 II 'and III = 5') and scraping (IV). Significant differences were observed in the abundance of meiofauna groups and composition, abundance and diversity of Nematoda genera. Through the scraping method the highest values of this community descriptors were found, indicating this method as the most efficient for the sampling of meiofauna of reefs. In Paripueira reef ecosystem 10meiofauna samples in two reef areas and 10 samples from the tidal pools around the reefs in these two areaswere collected in two periods of sampling. All samples were taken randomly. Ten samples of water column surrounding reefs were also done for the two reef areas. To evaluate the structural complexity of the reef, the chain link method was carried out in the two areas, to estimate the rugosity index. We identified 75 genera of Nematoda in the reef ecosystems. Data were analyzed using univariate and multivariate analysis. The reef areas differ significantly in terms of nematofauna and related to habitat complexity. It can be concluded that reefs have a typical of the nematofauna. The influence of the exploitation of reefs for tourism may have overlapped the habitat complexity as a factor structuring the Nematoda community.