Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Bacterivory in the common foraminifer Ammonia tepida: isotope tracer experiment and the controlling factors

Abstract : The majority of sediment dweller foraminifera are deposit feeders. They use their pseudopodia to gather sediment with associated algae, organic detritus and bacteria. Uptake of bacteria by foraminifera have been observed but rarely quantified. We measured uptake of bacteria by the common foraminifera Ammonia tepida using 15N pre-enriched bacteria as tracers. In intertidal flats, seasonal, tidal and circadian cycles induce strong variations in environmental parameters. Grazing experiments were performed in order to measure effects of abiotic (temperature, salinity and irradiance) and biotic (bacterial and algal abundances) factors on uptake rates of bacteria. In mean conditions, A. tepida grazed 78 pgC ind-1 h-1 during the first eight hours of incubation, after which this uptake rate decreased. Uptake of bacteria was optimal at 30°C, decreased with salinity and was unaffected by light. Above 7 × 108 bacteria ml wt sed-1, uptake of bacteria remained unchanged when bacterial abundance increased. Algal abundance strongly affected algal uptake but did not affect uptake of bacteria. As uptake of bacteria represented 8 to 19% of microbes (algae plus bacteria) uptake, Ammonia seemed to be mainly dependant on algal resource.
Type de document :
Article dans une revue
Liste complète des métadonnées

Littérature citée [61 références]  Voir  Masquer  Télécharger
Contributeur : Pierre-Yves Pascal <>
Soumis le : vendredi 4 juillet 2008 - 19:04:51
Dernière modification le : mardi 8 décembre 2020 - 09:59:05
Archivage à long terme le : : vendredi 28 mai 2010 - 23:12:09


Fichiers produits par l'(les) auteur(s)




Pierre-Yves Pascal, Christine Dupuy, Pierre Richard, Nathalie Niquil. Bacterivory in the common foraminifer Ammonia tepida: isotope tracer experiment and the controlling factors. Journal of Experimental Marine Biology and Ecology, Elsevier, 2008, pp.55-61. ⟨10.1016/j.jembe.2008.02.018⟩. ⟨hal-00293541⟩



Consultations de la notice


Téléchargements de fichiers