FN Archimer Export Format PT J TI Trophic niche of the invasive gregarious species Crepidula fornicata , in relation to ontogenic changes BT AF Androuin, Thibault Dubois, Stanislas Hubas, Cédric Lefebvre, Gwendoline Le Grand, Fabienne Schaal, Gauthier Carlier, Antoine AS 1:1,2;2:2;3:3;4:4;5:4;6:4;7:2; FF 1:PDG-ODE-DYNECO-LEBCO;2:PDG-ODE-DYNECO-LEBCO;3:;4:;5:;6:;7:PDG-ODE-DYNECO-LEBCO; C1 ISMER, UQAR, Rimouski, Canada IFREMER, DYNECO-LEBCO, Technopole Brest-Iroise, CS10070, Plouzané, France UMR BOREA, Muséum National d’Histoire Naturelle, Concarneau, France UMR CNRS 6539, LEMAR-IUEM-UBO, Plouzané, France C2 UNIV QUEBEC (UQAR-ISMER), CANADA IFREMER, FRANCE MNHN, FRANCE CNRS, FRANCE SI BREST SE PDG-ODE-DYNECO-LEBCO PDG-RBE-PFOM-LPI UM LEMAR TC 0 UR https://archimer.ifremer.fr/doc/00764/87639/93079.pdf LA English DT Article CR EVOCREP-2014 BO Albert Lucas DE ;Crepidula fornicata;trophic niche;ontogenic shift;fatty acids;stable isotopes;pigments;Bay of Brest AB The slipper limpet Crepidula fornicata is a common and widespread invasive gregarious species along the European coast. Among its life-history traits, well documented ontogenic changes in behavior (i.e., motile male to sessile female) suggests a potential shift in feeding strategy across its life stages. Considering the ecological significance of this species in colonized areas, understanding how conspecifics share the trophic resource is crucial. Using fatty acids (FA) and stable isotopes (SI) as complementary trophic markers, we conducted a field survey between late winter and spring to investigate the trophic niche of three ontogenic stages of C. fornicata that bear different sexual (male/female) and motility (motile/sessile) traits. Potential trophic sources were characterized by their pigment, FA and SI compositions and discriminated well over the study period. We showed that the biofilm covering C. fornicata shells harbored a higher biomass of primary producers (i.e., chlorophytes and diatoms) than the surrounding sediment surface. Over the study period, we observed a covariation between the three ontogenic stages for both FA and SI compositions which suggest that the trophic niche of C. fornicata does not change significantly across its benthic life. During periods of low food availability, slipper limpets displayed an opportunistic suspension-feeding behaviour, relying on both fresh and detrital organic matter, likely coming from superficial sedimentary organic matter. During high food availability (i.e., spring phytoplankton bloom), all ontogenic stages largely benefited from this fresh supply of organic matter (pelagic diatoms in this case). However, the three ontogenic stages showed consistent differences in FA composition, and to a lesser extent in SI composition. These differences persist over time, as they originate more likely from ontogenic physiological changes (e.g., differential growth rates, metabolic rate or gametogenesis) rather than diet discrepancies. PY 2020 PD JAN SO BioRxiv PU Cold Spring Harbor Laboratory DI 10.1101/2020.07.30.229021 ID 87639 ER EF