Trophic niche of the invasive gregarious species Crepidula fornicata, in relation to ontogenic changes

Date 2020
Author(s) Androuin ThibaultORCID1, 2, Dubois StanislasORCID2, Hubas CédricORCID3, Lefebvre Gwendoline4, Le Grand Fabienne4, Schaal GauthierORCID4, Carlier AntoineORCID2
Affiliation(s) 1 : ISMER, UQAR, Rimouski, Canada
2 : IFREMER, DYNECO-LEBCO, Technopole Brest-Iroise, CS10070, Plouzané, France
3 : UMR BOREA, Muséum National d’Histoire Naturelle, Concarneau, France
4 : UMR CNRS 6539, LEMAR-IUEM-UBO, Plouzané, France
DOI 10.17882/75809
Publisher SEANOE
Keyword(s) Crepidula fornicata, trophic niche, ontogenic shift, fatty acids, stable isotopes, pigments, Bay of Brest
Abstract

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) suggest 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 showed well discriminated compositions over the studied 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. Over the studied 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. However, 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). 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 from ontogenic physiological changes (differential growth rates, metabolic rate or gametogenesis) rather than diet discrepancies. This study revealed that multiple trophic markers allow high complementary to characterize organic matter as well as food partitioning between conspecific organisms.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) suggest 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 showed well discriminated compositions over the studied 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. Over the studied 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. However, 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). 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 from ontogenic physiological changes (differential growth rates, metabolic rate or gametogenesis) rather than diet discrepancies. This study revealed that multiple trophic markers allow high complementary to characterize organic matter as well as food partitioning between conspecific organisms.

Licence CC-BY-NC-SA
Data
File Size Format Processing Access
Stable isotopes data of three potential food sources 3 KB CSV Raw data Open access
HPLC pigments data of three potential food sources 13 KB CSV Raw data Open access
Fatty acids data of three potential food sources 34 KB CSV Raw data Open access
Stable isotopes data of three ontogenic classes of Crepidula fornicata 5 KB CSV Raw data Open access
Fatty acids data of three ontogenic classes of Crepidula fornicata 66 KB CSV Raw data Open access
FA concentration 1 KB CSV Raw data Open access
R code 24 KB R code Open access
R code 13 KB R Code Open access
R code 9 KB R Code Open access
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How to cite 

Androuin Thibault, Dubois Stanislas, Hubas Cédric, Lefebvre Gwendoline, Le Grand Fabienne, Schaal Gauthier, Carlier Antoine (2020). Trophic niche of the invasive gregarious species Crepidula fornicata, in relation to ontogenic changes. SEANOE. https://doi.org/10.17882/75809