Sabadel, AmandineGay, MelanieLane, Henry SBourgau, OdileBury, Sarah JDelgado, JosetteDuflot, Maureen2025-05-132025-05-132024-11-11Journal of Fish Diseases, ISSN: 0140-7775 (Print); 1365-2761 (Online), Wiley, 48(2), e14043-. doi: 10.1111/jfd.140430140-77751365-2761http://hdl.handle.net/10292/19189Anisakis simplex larvae, commonly found in marine fish, cause anisakiasis in humans, resulting in gastric to gastro-allergic symptoms. Despite known health risks, the impact of Anisakidae larvae on fish hosts is less understood. This study aimed to investigate this interaction by assessing the feeding strategy of A. simplex. Anisakis larvae were isolated from North Sea Merluccius merluccius tissues (stomach, body cavity, liver and muscle) and were analysed for carbon (δ13C) and nitrogen (δ15N) isotope values. Significant differences in δ13C values were found among host tissues, with the liver differing from muscle and stomach tissues. In contrast, no differences were noted for the associated parasites. Additionally, δ15N values indicated that the host occupied a significantly higher relative trophic position than its parasite. This suggests a lack of direct nutrient transfer from host to parasite, as the parasite would typically exhibit higher stable isotope values than the tissue they feed on. Therefore, A. simplex's stable isotope values might reflect those of its previous host (crustacean and/or small fish), providing insights into diet and movement of the paratenic M. merluccius host. Further research is needed to confirm these findings across different fish species and to explore A. simplex as a proxy for trophic ecology.This is the peer reviewed version of the following article: [see Source], which has been published in final form at https://doi.org/10.1111/jfd.14043. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.AnisakidaeNorth Seacarbonfeeding behaviourfish hosthakenitrogennutrientδ13Cδ15N30 Agricultural, Veterinary and Food Sciences3005 Fisheries SciencesDigestive Diseases2.2 Factors relating to the physical environment0608 Zoology0704 Fisheries Sciences0707 Veterinary SciencesFisheries3009 Veterinary sciencesAnimalsAnisakisFish DiseasesNitrogen IsotopesAnisakiasisCarbon IsotopesGadiformesLarvaHost-Parasite InteractionsFeeding BehaviorAnimalsGadiformesAnisakisAnisakiasisFish DiseasesCarbon IsotopesNitrogen IsotopesFeeding BehaviorLarvaHost-Parasite InteractionsAnimalsAnisakisFish DiseasesNitrogen IsotopesAnisakiasisCarbon IsotopesGadiformesLarvaHost-Parasite InteractionsFeeding BehaviorJournal ArticleOpenAccess10.1111/jfd.14043