Gut content metabarcoding of six crustaceans provides detailed diet description and insights into their roles as predators and scavengers

• Published in: Journal of Sea Research
• Main Authors: Boët, Pauline, Kopp, Dorothée, Méhault, Sonia, Morfin, Marie, Bonin, Aurélie, Lejeune, Benjamin
• Other Authors: Dynamique et durabilité des écosystèmes : de la source à l’océan (DECOD), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Laboratoire d'Ecologie Alpine (LECA ), Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Centre d'Ecologie et des Sciences de la COnservation (CESCO), Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: North-East Atlantic; DNA molecular analysis; Diet composition; Benthic invertebrates; Crustacean decapods; Trophic ecology; [SDV.SA.STP]Life Sciences [q-bio]/Agricultural sciences/Sciences and technics of fishery; North East Atlantic
• Online Access: https://hal.inrae.fr/hal-04646798; https://doi.org/10.1016/j.seares.2024.102509

International audience While many studies have analyzed the diet of marine consumers using traditional morphology-based methods, the integral diet of many species of functionally important groups such as benthic invertebrates remains poorly resolved. This hinders our ability to precisely establish trophic links among species, which is necessary to understand food webs and ecosystem dynamics. Here, we applied DNA metabarcoding to obtain a high resolution picture of the animal fraction of the diet of six species of crustaceans in the Bay of Biscay; the edible crab Cancer pagurus, the velvet crab Necora puber, the circular crab Atelecyclus undecimdentatus, the spider crab Maja brachydactyla, the shrimp Crangon crangon, and the hermit crab Pagurus bernhardus. We used two pairs of primers targeting the 18S rDNA (generalist) and 12S rDNA (fish-specific) regions to identify prey that makes up the animal fraction of the diet. Based on occurrence data, 54 prey taxa belonging to 5 different phylum mostly represented by teleost fishes and malacostracans were identified. Through a high-level of prey detection, results indicate a scavenging strategy across all consumers mostly based on the consumption of preys likely originating from fishing discards. This study also reveals patterns of niche overlaps among consumers differentiating C. crangon from others and suggesting high overlap in animal resource use between N. puber and M. brachydactyla as well as C. pagurus. High resolution diet description revealed the complexity of trophic interactions on a local scale.