Danny Rejas, Thierry Oberdorff, Steven A. J. Declerck, Monika Winder
{"title":"The introduced Arapaima gigas in the Bolivian Amazon: Trophic position and isotopic niche overlap with native species","authors":"Danny Rejas, Thierry Oberdorff, Steven A. J. Declerck, Monika Winder","doi":"10.1111/eff.12734","DOIUrl":null,"url":null,"abstract":"<p>Non-native fish species may generate major ecological impacts on native assemblages. This study aims to assess the potential impact of the introduced <i>Arapaima gigas</i> on native fish assemblages in two oxbow lakes of the Bolivian Amazon. Stable isotope data were used to determine trophic position (TP) and isotopic niche overlap, to evaluate potential predation and competition interactions, respectively. Results suggest that <i>A. gigas</i> is more an omnivore than a top predator, as often claimed. <i>Arapaima gigas</i> occupied an intermediate TP between detritivore/herbivore and piscivore fish species and showed broader isotopic niche compared to most native species analysed. The isotopic niche of <i>A. gigas</i> significantly overlapped with most native fish species in one lake (i.e. Lake Mentiroso), while there was low niche overlap in the second (i.e. Lake Miraflores). Given its omnivorous tendencies, the predation impact of <i>A. gigas</i> on other fish species is likely less than currently claimed and likely varies with the food web structure of the ecosystem. More precise data on resource availability and use are necessary to infer whether niche overlap will have negative impacts on native fish species through potential competitive interactions. Increasing our understanding on the processes generating impact of these introductions on resident communities through food web ecology will pave the way for better resource management and conservation efforts.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":null,"pages":null},"PeriodicalIF":1.6000,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.12734","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ecology of Freshwater Fish","FirstCategoryId":"97","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/eff.12734","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"FISHERIES","Score":null,"Total":0}
引用次数: 0
Abstract
Non-native fish species may generate major ecological impacts on native assemblages. This study aims to assess the potential impact of the introduced Arapaima gigas on native fish assemblages in two oxbow lakes of the Bolivian Amazon. Stable isotope data were used to determine trophic position (TP) and isotopic niche overlap, to evaluate potential predation and competition interactions, respectively. Results suggest that A. gigas is more an omnivore than a top predator, as often claimed. Arapaima gigas occupied an intermediate TP between detritivore/herbivore and piscivore fish species and showed broader isotopic niche compared to most native species analysed. The isotopic niche of A. gigas significantly overlapped with most native fish species in one lake (i.e. Lake Mentiroso), while there was low niche overlap in the second (i.e. Lake Miraflores). Given its omnivorous tendencies, the predation impact of A. gigas on other fish species is likely less than currently claimed and likely varies with the food web structure of the ecosystem. More precise data on resource availability and use are necessary to infer whether niche overlap will have negative impacts on native fish species through potential competitive interactions. Increasing our understanding on the processes generating impact of these introductions on resident communities through food web ecology will pave the way for better resource management and conservation efforts.
期刊介绍:
Ecology of Freshwater Fish publishes original contributions on all aspects of fish ecology in freshwater environments, including lakes, reservoirs, rivers, and streams. Manuscripts involving ecologically-oriented studies of behavior, conservation, development, genetics, life history, physiology, and host-parasite interactions are welcomed. Studies involving population ecology and community ecology are also of interest, as are evolutionary approaches including studies of population biology, evolutionary ecology, behavioral ecology, and historical ecology. Papers addressing the life stages of anadromous and catadromous species in estuaries and inshore coastal zones are considered if they contribute to the general understanding of freshwater fish ecology. Theoretical and modeling studies are suitable if they generate testable hypotheses, as are those with implications for fisheries. Manuscripts presenting analyses of published data are considered if they produce novel conclusions or syntheses. The journal publishes articles, fresh perspectives, and reviews and, occasionally, the proceedings of conferences and symposia.