Unravelling the distribution of three Ammonia species (Foraminifera, Rhizaria) in French Atlantic Coast estuaries using morphological and metabarcoding approaches

• Published in: Marine Micropaleontology
• Main Authors: Fouet, Marie P.A., Schweizer, Magali, Singer, David, Richirt, Julien, Quinchard, Sophie, Jorissen, Frans, J
• Other Authors: Laboratoire de Planétologie et Géosciences - Angers (LPG-ANGERS), Laboratoire de Planétologie et Géosciences UMR_C 6112 (LPG), Le Mans Université (UM)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Le Mans Université (UM)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), projet FORESTAT (financement OFB et Univ Angers)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: Foraminifera; Biogeography; Pseudo-cryptic species; Invasive species; [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; North Atlantic
• Online Access: https://hal.science/hal-04525229; https://hal.science/hal-04525229/document; https://hal.science/hal-04525229/file/Clear_version_Corrections_Fouet%20et%20al.pdf; https://doi.org/10.1016/j.marmicro.2024.102353

International audience Assessing the distribution of species in natural environments is essential for their use in environmental surveys. Here, we investigate the distribution of three pseudo-cryptic species formerly lumped in the morphospecies Ammonia tepida (Cushman, 1926), commonly found on estuarine mudflats along the European coasts: Ammonia veneta Schultze, 1854 (T1), Ammonia aberdoveyensis Haynes, 1973 (T2) and Ammonia confertitesta Zheng, 1978 (T6). We studied their distribution at 51 sites located in seven estuaries of the French North Atlantic coast (Elorn, Aulne, Odet, Crac'h, Auray, Vilaine, Vie), using both morphological and molecular identification methods. Ammonia veneta was detected by both approaches at most of the stations. While A. aberdoveyensis was frequently identified by the morphological method but not detected with metabarcoding, the presence of A. confertitesta in the eDNA data often contrasted with its absence in the morphological analysis. The absence of A. aberdoveyensis in eDNA of sites where it was identified morphologically could be the consequence of its relative scarcity, and eventually a patchy distribution. Concerning A. confertitesta, we hypothesise that these contradictory results can be explained by the supposedly invasive character of this species. Despite the widespread presence of A. confertitesta genetic material (including adults, juveniles and propagules), a mature population has not yet fully developed everywhere. The seven investigated estuaries seem to represent different stages of replacement of the autochthonous species A. veneta and A. aberdoveyensis by A. confertitesta. Our study demonstrates that the combination of visual observations and molecular approaches is ideal for monitoring the progressive spreading of exotic species.