Heterotrophic protists as a trophic link between picocyanobacteria and the pearl oyster Pinctada margaritifera in the Takapoto lagoon (Tuamotu Archipelago, French Polynesia)
|Author(s)||Loret Pascale, Le Gall Solange, Dupuy Christine, Blanchot Jean, Pastoureaud Annie, Delesalle Bruno, Caisey Xavier, Jonquieres Gerard|
|Affiliation(s)||Univ Perpignan, URA CNRS 1453, EPHE, F-66860 Perpignan, France.
CREMA, F-17137 Lhoumeau, France.
Univ La Rochelle, LBEM, F-17042 La Rochelle, France.
IRD, Stn Biol Roscoff, F-29682 Roscoff, France.
IFREMER, COP, Tahiti, Fr Polynesia.
|Source||Aquatic Microbial Ecology (0948-3055) (Inter-Research), 2000-10 , Vol. 22 , N. 3 , P. 215-226|
|WOS© Times Cited||31|
|Keyword(s)||Trophic resource, Picoplankton, Pinctada margaritifera, Pearl oysters, Atoll lagoon, Protists|
|Abstract||Pearl oysters are farmed in oligotrophic tropical atoll lagoons where planktonic communities are dominated by production from cyanobacteria smaller than 2 pm. Paradoxically, the pearl oyster Pinctada margaritifera only retains particles larger than 2 Pm. In this study, we assess the relative contribution of hetero/mixotrophic microbiota to the available planktonic resource. In Takapoto Atoll, picocyanobacteria are the dominant biomass (20 mug C l(-1)). The carbon biomass of ciliates and dinoflagellates ranges from 1 to 24 and 0.5 to 5 mug C l(-1) respectively, with a mean of 6 mug C l(-1) for ciliates and 2 mug C l(-1) for dinoflagellates. The possible retention by P. margaritifera on a natural protist suspension was investigated. Due to its high clearance rates (ca 20 l h(-1) g(-1)) the pearl oyster retained 85 mug C h(-1) g(-1) from ciliates and 55 mug C h(-1) g(-1) from dinoflagellates. Conversely, cyanobacteria were not efficiently retained by the bivalve and did not efficiently contribute to its diet. From our experiments, we concluded that hetero/mixotrophic protists rapidly and efficiently process the picoplanktonic resource towards filter-feeders, particularly pearl oysters.|