Ecologia trÃfica do Octocoral Carijoa riisei (Duchassaing &Michelotti, 1860) (Cnidaria, Alcyonacea) em Porto de Galinhas (Pernambuco, Brasil)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Carijoa riisei is the most abundant species of octocoral for the coast of Pernambuco. To know the importance of local species in the food chain, a search was conducted, divided into two stages: the first aiming to discover the food composition and possible seasonal and bathymetric fluctuations, and the second focusing on the degree of selectivity of the octocoral prey available on plankton. The colonies of octocoral were collected on the beach of Porto de Galinhas, on two and six meters deep, in January, June, October 2006 and March 2007 for the first study, and in January, March and June for the second study. We analyzed the contents of the gastric cavity of C. riisei polyps and samples of plankton. The results of the first study revealed the presence of 102 phytoplankton organisms and 25 zooplanktonts in the content of the polyps. The cyanophytes representing 46% of the total biomass ingested. Significant differences were found with regard to wealth, between the months of June and October to 2m. Regarding the abundance and diversity, both had significant differences with respect to seasonality and bathymetry. The results of the second work shows that the sizes of the items of prey were lower when compared to the items available on plankton. There was no significant difference with respect to size between January and March, but in June showed smaller sizes. There was a significant positive correlation between the abundance of prey available on plankton and the content of polyps of C. riisei. The diatom Mastogloia sp. and the cyanophyte Oscillatoria sp. had the highest rates of positive selectivity. The results reviewed, the octocoral C. riisei, in the Brazilian Northeast coast is behaving as opportunistic species poliphagous with suspensive and filter food habit liabilities

ASSUNTO(S)

ecology porto de galinhas oportunista suspensive suspensÃvora ecologia opportunistic ecologia porto de galinhas

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