Comunidade de CrustÃceos DecÃpodos InfralitorÃneos dos Recifes da Praia de Porto de Galinhas (PE)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Northeastern Brazilian coral reefs, as found in Porto de Galinhas beach â PE, are known as areas of complex and diverse biological interactions and high biological productivity (primary productivity). In addition, they represent a reproductive zone, and serve as nursery, shelter and alimentation source for a major part of the marine fauna. Porto de Galinhas-PE pertains to Ipojuca, southern littoral of Pernambuco, and represents one of the main tourist attractions of the state. Coral reefs are very complex and fragile ecosystems. Scientific studies are thus of critical importance for effective conservation of marine fauna and long term environmental sustainability of these ecosystems. The objective of this study was to analyze infralittoral decapods crustacean community of the beach of Porto de Galinhas, using and creating a new sampling technique for this group; the visual census. A preliminary bibliographic survey was done and included an analysis of the specimens of the Carcinological collection, to identify the possible faunal composition of infralittoral decapods crustaceans of the reef ecosystem of Porto de Galinhas. Then was realized a preliminary in situ sampling of reef decapods species from April 2003 to May 2004. Sampling was done manually using scuba diving and snorkeling techniques. Specimens were also collected on exposed reefs at low tide. A nocturnal visual census technique was developed for the ecological analysis of the macro-decÃpodol community. This new visual census technique was created based on existing sampling methods and involved a sweep of pre-fixed inclined transects. Twelve visual censuses were performed for each of the twelve sample sites at low-tide during full-moon, from May 2004 to May 2005, for a total of 144 samples for the coral bench of Porto de Galinhas. From the bibliographic survey of this study area, 45 decapods species were identified. During the preliminary in situ sampling, 42 decapods species were encountered. From those, three species came from inter-tidal sampling of exposed reefs and 39 species were collected using snorkeling and scuba diving techniques. Among the species collected using scuba diving techniques, 26 represented new decapods occurrences for the study area. One of them might be a new species as it shows unique morphological attributes. These findings illustrate the importance of scuba diving for sampling of aquatic benthic organisms. From the bibliographic survey and the in situ sampling, the faunal survey totalized 71 different species of decapods for the study area. During the visual censuses of the coral bench, a total of 6.280 individuals from 37 species were observed, for a mean of 5.4 (+/- 0.9) species by site. Species who showed highest abundance and frequency were respectively Cinetorhynchus rigens, Mithraculus forceps, and Panulirus echinatus. From the results of the visual censuses was proposed a zonation pattern for decapods species. The vertical species distribution was identified according to the following zones: reef fringe, reef slope, sea bottom and inferior and superior sections of caves. In the reef fringe and reef slope was found species from the domain of the superfamily Majoidea, at the sea bottom was predominant the domain of the superfamily Paguroidea, and in caves the domain of the superfamily Palinuroidea. This new technique of visual census was shown of great utility and represents a promising technique for nocturnal decapods species studies. Effectively, results from observed and collected species were analogous and the study showed results similar to those of various authors which used traditional sampling techniques. Moreover, this technique could potentially be used to study other nocturnal motile benthic faunal species

ASSUNTO(S)

censo visual recifes decÃpodos decapods reefs nocturne dive visual census porto de galinhas mergulho noturno porto de galinhas engenharia naval e oceanica

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