MEPS 240:291-295 (2002)  -  doi:10.3354/meps240291

δ13C versus δ15N of co-occurring molluscs within a community dominated by Crassostrea gigas and Crepidula fornicata (Oosterschelde, The Netherlands)

P. Riera1,2,*, L. J. Stal2, J. Nieuwenhuize2

1Station Biologique de Roscoff, Université Pierre & Marie Curie Paris VI - CNRS, Place Georges-Teissier, BP 74, 29682 Roscoff cedex, France
2Centre for Estuarine and Coastal Ecology, Netherlands Institute of Ecology (NIOO-CEMO), Postbus 140, 4400 AC Yerseke, The Netherlands

ABSTRACT: The aim of this study was to investigate, by use of δ13C and δ15N, the diet of co-occurring intertidal molluscs species within a community dominated by the oyster Crassostrea gigas and its epibiont, the common Atlantic slipper limpet Crepidula fornicata. The results showed that the δ13C versus δ15N values of C. gigas differed from those of the deposit feeders considered but also from the other suspension-feeding molluscs (i.e. Mytilus edulis, Cerastoderma edule and C. fornicata), being more depleted in 13C and in 15N. The results suggest more similarities in the assimilated food sources of C. fornicata, C. edule and M. edulis. In particular, the δ13C and δ15N differences between C. gigas and C. fornicata suggest that these associated suspension feeders in many shellfish culture areas may not necessarily be competitors for food sources when food is not limited.

KEY WORDS: Benthic food web · δ13C · δ15N · Molluscs · Crassostrea gigas · Crepidula fornicata · Oosterschelde

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