Influence des conditions trophiques sur le développement larvaire de l'espèce invasive Crepidula fornicata: conséquences sur ses capacités de dispersion
Leroy, F. (2011). Influence des conditions trophiques sur le développement larvaire de l'espèce invasive Crepidula fornicata: conséquences sur ses capacités de dispersion. PhD Thesis. Université Pierre et Marie Curie: Paris. 210 pp.
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| Abstract |
Introductions of exotic species are one of the major causes of alteration of coastal marine ecosystems. The pelagic larval phase of bentho-pelagic cycle invertebrates plays a major role at all stages of the introduction process and can contribute to the success or failure of an introduction. The study of mechanisms modulating larval life history traits is therefore essential for the understanding of the introduction processes. The overall goal of my PhD work is to determine the influence of food availability (in terms of quantity and quality) on larval developmental abilities of Crepidula fornicata, an emblematic gastropod of biological introductions to the ribs. European. This issue is complex because in its area of introduction, C. fornicata has a long reproductive period (from February to November) which implies (1) that the maternal investment for the offspring may vary throughout this period and ( 2) the larvae emitted are in the presence of variable food sources. The results obtained showed, thanks to enriched isotopic tracing (13C), that encapsulated embryos depended mainly on maternal investment for their development. The study of the fatty acid composition (essential energy source for the offspring and quality biomarkers) of females, embryos and larvae showed a better quality of females and embryos in the middle of the reproductive period. The study of larval nutrition, using double isotopic labeling (13C, 15N) and grazing experiments on natural planktonic communities, showed that the larvae of C. fornicata (1) preferentially use nanoplankton ( including diatoms), and (2) have the ability to feed from the bacterial compartment. These results, combined with in situ monitoring data and results from lipid biomarker use, demonstrate the ability of C. fornicata larvae to feed on a wide range of nutrient sources, both qualitatively and quantitatively. . It is proposed that these trophic abilities have contributed to the expansion of this species on European coasts. |
| Dataset |
- Comtet, T; Leroy, F (2019): Phytoplankton monitoring at the Château du Taureau Station in the Western English Channel, from 2009 to 2011, more
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