Bivalve trophic ecology in the Mediterranean: Spatio-temporal variations and feeding behavior

Ariadna Purroy (1) , Mirjana Najdek , Enrique Isla (2) , Ivan Zupan (3) , Julien Thébault (4) , Melita Peharda (1)

1 Faculty of Maritime Studies [Split]
2 ICM - Institute of Marine Sciences / Institut de Ciències del Mar [Barcelona]
3 University of Zadar
4 LEMAR - Laboratoire des Sciences de l'Environnement Marin (LEMAR)

The trophic ecology of two bivalves, the clam Callista chione and the cockle Glycymeris bimaculata was studied using environmental and biochemical variables of the suspended particulate matter and the sediment. Samples were collected from two shallow sites, Pag and Cetina, in the coastal oligotrophic Mediterranean Sea, during a 17 month period. The temporal variation of the particulate matter reflected a mixture between marine and terrestrial sources throughout the year, with a clear marine influence during summer and fall, and predominance of terrestrial inputs during spring and winter. The digestive gland was a useful rapid turnover tissue, where the carbon isotope signal was species-specific and the nitrogen isotope one was site-specific. FA markers in the digestive gland revealed a mixed diet where Callista chione fed more upon fresh material than G. bimaculata which relied largely on bacteria-derived detritus. Overall, little feeding niche overlap was observed between the two species during the year, indicating resource partitioning, expected for a food-limited system. The present trophic ecology study in co-occurring species allowed identifying species-specific feeding adaptations to environmental variability.

Mots clés: ACL; Fatty acids; community structure; Stable isotopes; Bivalves; fatty-acid-composition; Coastal ecosystems; marennes-oleron bay; mytilus-edulis; food sources; phytoplankton blooms; particulate organic-matter; Adriatic sea; Biochemical variables; Feeding ecology; Niche partitioning; nitrogen isotope ratios; Suspension feeder

Domaines: Biodiversité et Ecologie

Ariadna Purroy, Mirjana Najdek, Enrique Isla, Ivan Zupan, Julien Thébault, et al.. Bivalve trophic ecology in the Mediterranean: Spatio-temporal variations and feeding behavior. Marine Environmental Research, 2018, 142, pp.234-249. ⟨10.1016/j.marenvres.2018.10.011⟩. ⟨hal-02640334⟩