Ecology of Freshwater Fish最新文献

{"title":"Prey Availability and Diet of Early Life Stages of Lake Whitefish (Coregonus clupeaformis) in the Fishing Islands of Lake Huron","authors":"Issac Hébert,&nbsp;Erin S. Dunlop","doi":"10.1111/eff.70010","DOIUrl":"https://doi.org/10.1111/eff.70010","url":null,"abstract":"<p>Declines in recruitment of lake whitefish (<i>Coregonus clupeaformis</i>) in the Laurentian Great Lakes have been attributed to a reduction in the amount of zooplankton prey available to young life stages, stemming from the ecosystem effects of invasive dreissenid mussels. Here, we examine the diets of two life stages of lake whitefish, the larval and post-larval stages, in relation to zooplankton availability in the environment at a historically important spawning shoal complex in Lake Huron to better understand the potential for food limitation to influence the growth and survival of these critical early life stages. The digestive tracts of larval (size range 12–26 mm) and post-larval (size range 23–43 mm) lake whitefish were extracted, and contents were identified and enumerated to describe feeding strategies and calculate electivity indices to assess selection for specific prey groups and sizes. We found that the amount of food consumed varied among years and there was an ontogenetic shift in feeding strategy, with larval fish having a more generalist diet than post-larval fish. The most important prey items were calanoid copepods for larvae and copepods and adult/pupa staged dipterans for post-larval fish. Zooplankton densities in the environment were often low, variable among years, and mostly comprised of the smallest zooplankton taxa, nauplii, which were the least preferred prey group of larval fish. The peak in zooplankton density was variable among years, including being absent, and occurred after the peak of larval abundance. Thus, it is possible that low zooplankton availability is increasing the scope for food limitation and contributing to recruitment variation in this population.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144140468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mesohabitat Evaluation Reveals Variable Abundances and Habitat Choice in Juvenile Atlantic Salmon Across Diverse Habitats in the Main Stem of a Large Sub-Arctic River","authors":"Tuomas Metsäniemi,&nbsp;Panu Orell,&nbsp;Anders Foldvik,&nbsp;Jorma Kuusela,&nbsp;Mika Kurkilahti,&nbsp;Jaakko Erkinaro","doi":"10.1111/eff.70009","DOIUrl":"https://doi.org/10.1111/eff.70009","url":null,"abstract":"<p>Large main stem rivers typically provide a variety of mesohabitat types, but their abundance, distribution and role in providing habitat for juvenile salmonids have rarely been analysed. The quantity of meso-scale habitats and their juvenile Atlantic salmon abundance was surveyed in the large sub-arctic River Teno in northernmost Fennoscandia. Different habitat types were mapped using the Norwegian Mesohabitat Classification Method (NMCM). Juvenile salmon abundance in different mesohabitats, on various substrates, depths and lateral positions across the channel was estimated by electrofishing boat surveys. Most of the Teno main stem (67%) was dominated by fine substrate and &gt; 50 cm s⁻¹ flow velocity. Typical juvenile salmon-rearing habitats, such as rapids, riffles and glides, comprised 32% of the riverbed. Data from NMCM and electrofishing surveys were used in generalised linear models to describe the relationship between habitat variables and juvenile salmon (YOY and parr) abundance. Juvenile abundance varied a lot across and within mesohabitats; in general, abundance was higher in areas with depth ≤ 70 cm than in deeper areas, and in middle sections of the river compared to those near shorelines. Juvenile salmon were documented also in sandy areas, although in low abundances, and in relatively high abundances in areas deeper than typically considered important for juvenile salmon. These areas should be considered in assessing habitat potential for juvenile salmon production. NMCM proved to be a fast, cost-effective method for surveying large areas for habitat assessment.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hierarchical Modelling Reveals Local Environmental Metrics as Key Predictors of Fish Stream Assemblage Structure","authors":"Fabiane Barreto Souza,&nbsp;Alexandre Clistenes Alcântara Santos,&nbsp;André Teixeira da Silva,&nbsp;Nuno Caiola","doi":"10.1111/eff.70006","DOIUrl":"https://doi.org/10.1111/eff.70006","url":null,"abstract":"<div>\u0000 \u0000 <p>Environmental factors act at multiple spatial scales, shaping the fish assemblage structure in streams. Understanding catchment-stream relationships through hierarchical classification can aid in the conservation and management of freshwater ecosystems. The main goal of our work was to use the Hierarchical Modelling of Species Communities framework to answer the following questions: Which environmental variables are more important in structuring stream assemblages? Do ecomorphological traits influence species' responses to environmental conditions? What is the pattern of species co-occurrences along the streams? We fitted models with two alternative response datasets: a community matrix (site × species) with presence/absence data (PA) and abundance data (ABU). Species ecomorphological traits were also included in the models. We tested models considering the environmental variables at each scale separately (local and catchment) and considering all variables together. Variables at the local scale explained 57.1% (PA) and 53.3% (ABU) of the overall variance portion partitioning, while catchment variables explained only 36.6% and 23.3%, respectively. Traits explained only 47.9% (PA) and 18.93% (ABU) of the variation. No significant correlation between species co-occurrences was found. Our results suggest that local-scale metrics better predict the structure of fish assemblages in headwater streams from the Chapada Diamantina region of Caatinga.</p>\u0000 </div>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diet, Trophic Plasticity and Niche Dynamics of Four Barbel Species Across Elevational and Seasonal Gradients in a Mediterranean Stream","authors":"Abdelilah Ahnich,&nbsp;Fayçal Aitboumallassa,&nbsp;Hanane Khalki,&nbsp;Mohamed Naimi","doi":"10.1111/eff.70007","DOIUrl":"https://doi.org/10.1111/eff.70007","url":null,"abstract":"<div>\u0000 \u0000 <p>Conservation and effective management of freshwater ecosystems require detailed insights into species-specific dietary strategies, resource partitioning and ecological interactions, including competition for shared resources. This study investigates seasonal dietary shifts within four barbel species (<i>Atlantor reinii</i>, <i>Luciobarbus magniatlantis</i>, <i>Luciobarbus ksibi</i> and <i>Carasobarbus fritschii)</i> in the Zat Basin (Morocco). The study's objective is to inform conservation and ecosystem management planning that should be considered for threatened species, such as <i>A. reinii</i> and <i>L. magniatlantis</i>. We evaluated feeding strategies and niche partitioning across species and seasons using stomach content analysis and alimentary indices, including Dietary Index (DI) and occurrence (OC). <i>L. ksibi</i> demonstrated the highest insect consumption (OC = 51.11%, DI = 0.84%). <i>L. magniatlantis</i> showed the most diverse animal prey composition, with the highest <i>Mollusca</i> occurrence (OC = 76.67%, DI = 0.59%), substantial insect intake (OC = 54.07%, DI = 1.43%) and significant <i>Arachnida</i> presence (OC = 60%, DI = 0.54%). <i>A. reinii</i> displayed the highest selectivity for insects (DI = 1.14%). <i>C. fritschii</i> exhibited moderate insect consumption (OC = 36.30%, DI = 0.88%) and an equal preference for <i>Mollusca</i> and <i>Tubellaria</i> (both OC = 53.33%, DI = 0.38% and 0.64%, respectively). NMDS analyses revealed partial dietary overlap among species, with <i>A. reinii</i> and <i>C. fritschii</i> exhibiting distinct clustering, while <i>L</i>. <i>ksibi</i> and <i>L</i>. <i>magniatlantis</i> displayed broader nutritional niches. Moderate-to-high dietary niche overlap, particularly between <i>C. fritschii</i> and <i>L. ksibi</i>, highlights the potential for significant competition for shared prey resources, which may intensify during periods of resource scarcity. This study highlights species-specific dietary flexibility, emphasising the importance of adaptive foraging strategies in conservation planning and the ecological resilience of freshwater fish in Mediterranean streams.</p>\u0000 </div>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143889179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-Term Impact of Multiple Invasions on Fish Community Composition and Functional Richness","authors":"Fernando Córdova-Tapia,&nbsp;Abigail Santiago-Arellano,&nbsp;Isabel Salazar-Rueda,&nbsp;Alfredo F. Ojanguren,&nbsp;Morelia Camacho-Cervantes","doi":"10.1111/eff.12832","DOIUrl":"https://doi.org/10.1111/eff.12832","url":null,"abstract":"<div>\u0000 \u0000 <p>Invasive species are among the biggest threats to biodiversity and represent billions of dollars to the global economy. Invasive species pose a threat to the biodiversity of freshwater ecosystems, which are among the most vulnerable due to their isolation by terrestrial ecosystems and the impact of human activities. While invasive species in freshwater ecosystems are known to cause extinctions and therefore reduce species richness, little attention has been paid to their effects on functional richness. Here, we aimed to evaluate the species and functional richness of a wetland fish community that has been subjected to the introduction of exotic species in repeated events over four decades. Our study site, La Mintzita, was home to 15 native species, some of them endemic to the Central Mexican Plateau; the ongoing changes in the fish community have led to a current state where the richness of invasive species matches that of native species. Over the decades, functional richness has declined, dropping from 8.1 before 1985 to 2.8 in the 2020s. We found that in the 2020s, functional richness was significantly lower than expected by chance. The native species that might be locally extinct are those occupying similar functional niches as the invaders or those that are the most sensitive, thus indicating a process of fauna homogenisation. We highlight the importance of focusing conservation efforts on maintaining functional richness to preserve services derived from freshwater ecosystems.</p>\u0000 </div>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143770007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Diets of Invasive Blue Catfish: Differences Across Rivers and Ontogenetic Stages","authors":"Victoria D. Davis,&nbsp;Peter C. Sakaris,&nbsp;Timothy F. Bonvechio,&nbsp;Peter D. Hazelton,&nbsp;Martin J. Hamel","doi":"10.1111/eff.70001","DOIUrl":"https://doi.org/10.1111/eff.70001","url":null,"abstract":"<p>Blue Catfish (<i>Ictalurus furcatus</i>) are an invasive species with expanding populations in freshwater systems, posing significant ecological challenges to native fauna. To assess their potential impacts in diverse aquatic ecosystems, we examined and compared the diets of non-native Blue Catfish from four rivers in Georgia, USA, two of which drain into the Atlantic Ocean. A total of 936 Blue Catfish were collected from the Altamaha, Ocmulgee, Oconee, and Satilla rivers, with 90.38% of stomachs containing identifiable prey. Stomach content analysis revealed that Asian Clam (<i>Corbicula fluminea</i>) dominated their diet in terms of number (96.76%), weight (69.33%), and to a lesser degree, frequency (36.96%). Across rivers, smaller Blue Catfish (≤ 300 mm TL) had diets with a higher relative importance of insects and vegetation. Ontogenetic dietary trends showed increasing consumption of fishes and crustaceans as fish size increased in the Altamaha, Ocmulgee, and Oconee rivers. In contrast, the Satilla River population exhibited broader dietary diversity and distinct ontogenetic shifts. Stable isotope analysis (δ¹³C and δ¹⁵N) revealed significant differences between Blue Catfish from the Altamaha and Satilla rivers, underscoring their opportunistic feeding strategies in varying habitats. Bayesian niche overlap analysis indicated that size classes within the Altamaha and Satilla rivers had substantial intraspecific overlap, with Satilla subadults exhibiting the broadest niche (SEA_B: 3.83). Factors such as prey availability, density dependence, and environmental conditions likely influence prey selection and feeding strategies in these systems. Understanding these dynamics is crucial for managing the ecological impacts of invasive Blue Catfish in freshwater systems of North America.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Lotic Environmental Conditions on Larval Fish Growth and Prey Consumption","authors":"Erik M. Griffen,&nbsp;Michael J. Weber","doi":"10.1111/eff.70004","DOIUrl":"https://doi.org/10.1111/eff.70004","url":null,"abstract":"<p>Rivers throughout the United States have undergone extensive modifications, altering their original dynamic state. Knowledge of how flow and temperature regime alterations may affect foraging and growth of larval fishes is limited. We investigated the effects of discharge, growing degree days (GDD) and zooplankton densities on larval Sciaenidae and Catostomidae feeding success (probability of prey encountered in the stomach), prey consumption (number of prey consumed) and growth (length at age). We sampled ichthyoplankton and zooplankton from the Des Moines and Iowa rivers, Iowa, USA from April–June 2021 and 2022. Catostomidae feeding success on cladocerans and rotifers was negatively associated with prey density, while feeding success on copepods was positively associated with prey density; consumption of cladocerans was negatively associated with prey density, and consumption of copepods and rotifers was positively associated with prey density. Discharge was positively associated with Sciaenidae feeding success and consumption of cladocerans and Catostomidae consumption of cladocerans but negatively associated with Sciaenidae feeding success on copepods, Catostomidae feeding success on cladocerans, and Catostomidae feeding success and consumption of copepods. Water temperature was negatively associated with Sciaenidae and Catostomidae feeding success and consumption of cladocerans and positively associated with Catostomidae feeding success and consumption of copepods. Larval Sciaenidae growth was positively associated with copepod density, while Catostomidae growth was positively associated with cladoceran and rotifer densities. Catostomidae growth was negatively associated with copepod density and GDD. We did not find an effect of discharge for growth of either taxa. Our results suggest zooplankton density is an important limiting factor for larval fish growth, while environmental factors such as discharge and water temperature influence larval fish foraging in lotic systems.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upstream Migration Dynamics of Juvenile American Eels (Anguilla rostrata) Towards a Hydropower Dam in a Large River","authors":"Felix Eissenhauer,&nbsp;Tommi Linnansaari,&nbsp;Thomas C. Pratt,&nbsp;R. Allen Curry,&nbsp;Philip M. Harrison","doi":"10.1111/eff.70003","DOIUrl":"https://doi.org/10.1111/eff.70003","url":null,"abstract":"<p>Young American eels (\u0000 <i>Anguilla rostrata</i>\u0000 ) undergo a remarkable migration from oceanic spawning grounds to continental growth habitats. Impaired river connectivity can prevent facultatively catadromous eels from completing their upstream migration. The effects of barriers on the upstream migration dynamics of this endangered species remain poorly understood. This study evaluated the timing of juvenile eel migration and the spatial distribution and size/age structure of migrating eels within the tidal and hydropower-regulated Wolastoq | Saint John River in Canada. Upstream eel migration in this river is restricted by the Mactaquac Dam and Generating Station, located 150 km upstream of the sea. Approximately 36,000 eels were caught with fyke nets at various locations between the river mouth and the Mactaquac Dam, measured for length, and a subsample (<i>n</i> = 401) was aged via sagittal otolith readings. While glass eels (not fully pigmented juvenile eels) were observed up to 90 km upstream, approximately 20 km beyond the point of saltwater intrusion, eels arriving at the Mactaquac Dam were exclusively fully pigmented, with 80% being continental age 1+ or 2+. The mean length of juvenile eels increased with distance upstream. These results indicate that upstream eel migration in the Wolastoq | Saint John River can take multiple years and involves phases of juvenile residency. Our study provides important insights into juvenile eel migration in large rivers and implications for effective management of passage success at barriers such as hydropower dams.</p>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/eff.70003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143481328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-Year Spawning Migration as a Life-History Strategy of Sea Trout (Salmo trutta L.) in Large, High-Latitude River Systems","authors":"Linus Lähteenmäki,&nbsp;Riina Huusko,&nbsp;Gustav Hellström,&nbsp;Martin Snickars,&nbsp;Atso Romakkaniemi","doi":"10.1111/eff.70002","DOIUrl":"https://doi.org/10.1111/eff.70002","url":null,"abstract":"<div>\u0000 \u0000 <p>Migrating animals are found throughout the animal kingdom, as movement between habitats can be vital for survival, growth, and reproduction. Mature sea trout (<i>Salmo trutta</i> L.) undertake seasonal migrations from marine feeding areas to freshwater spawning habitats, but the migration dynamics may vary considerably between rivers of different morphology and location. In this study, we used radio-telemetry with multi-year tags to observe the riverine movements and spawning migration behaviour of wild sea trout tagged in a large, northern Baltic Sea river system, the Tornio River. Both immature and mature trout were observed to have similar overwintering behaviour as they mainly overwintered in the same locations in the lower river. Many immature trout returned to overwinter for multiple consecutive winters without spawning, a behaviour that has been rarely reported for sea trout in rivers of the northern Baltic Sea. The results from a support vector model highlighted the importance of trout age and previous spawning experience for the direction of the migration, as previously spawned and older trout were more likely to migrate upstream for spawning while their younger counterparts returned to sea in summer after spending the winter in freshwater. The riverine movement patterns indicate that the majority of mature sea trout migrating upstream for spawning in the river system have adopted a spawning migration strategy, which extends for almost two calendar years. Mature sea trout enter freshwater in autumn the year prior to spawning, migrate to spawning habitats and spawn in the year following freshwater entry, and overwinter in-river for a second time post-spawning. This migration strategy has not been previously reported for sea trout native to Baltic Sea river systems. The extended freshwater stays and numerous migrations between sea and river habitats in large, high-latitude rivers need to be considered in management to ensure adequate protection of both immature and mature sea trout.</p>\u0000 </div>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143424216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Rainbow Trout (Oncorhynchus mykiss) Introduction on Andean Stream Food Webs","authors":"Adriana Marcela Forero Cespedes,&nbsp;Sandra Bibiana Correa,&nbsp;Francisco Antonio Villa Navarro","doi":"10.1111/eff.70000","DOIUrl":"https://doi.org/10.1111/eff.70000","url":null,"abstract":"<div>\u0000 \u0000 <p>Introduced species are one of the biggest threats to aquatic ecosystems. Rainbow trout (<i>Oncorhynchus mykiss</i>, Salmonidae) is considered one of the most dangerous introduced predatory fish species, as they often put native species at risk of extinction. This study evaluated the effects of rainbow trout introduction on Andean stream food webs. We tested the hypothesis that the presence of rainbow trout changes Andean stream food webs by changing the diet of other carnivorous species and the energy source supporting native fish species. We sampled streams with and without rainbow trout and with different vegetation cover (i.e., pastures and crops versus forest) and combined data from stomach contents and stable isotopes. We analyed stomach contents from 231 specimens of two native catfish species and 116 rainbow trout specimens. Our results demonstrate that aquatic insects are essential in Andean stream food webs, where collector gatherers and scrapers were the most consumed and assimilated by catfish and rainbow trout species. Leaf litter was predicted to be the primary energy source in streams with forest cover. In contrast, periphyton contributed the most in streams with pastures and crops. We conclude that the presence of trout coupled with use/land cover (i.e., vegetation cover) exerts a substantial effect on Andean stream food webs. Protection of riparian forests of the Andean streams of Colombia is needed to guarantee the stability of aquatic food webs and thus help native species coexist with established non-native species introduced decades ago.</p>\u0000 </div>","PeriodicalId":11422,"journal":{"name":"Ecology of Freshwater Fish","volume":"34 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143380074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}