When giant amphibians rule the river: Community trophic structure of Japanese giant salamander ecosystems

food web structure; freshwater ecosystems; gigantism; isotopic niche; rivers; stable isotope analysis; top predator; trophic interactions; Andrias japonicus; Cryptobranchidae; Giant salamander; river communities; Apex predator; niche partitioning; Japan; trophic ecology; food web; feeding; food; Trophic position; fish; prawns; turles; frogs; crabs; Geothelphusa dehaani; Buergeria buergeri; Rhynchocypris oxycephala; Palaemon paucidens; Rhinogobius flumineus; Nipponocypris temminckii; Layman's metrics; carbon sources

Abstract :

[en] Top predators strongly influence food webs, often because they reach large body sizes. Amphibians are typically regarded as prey in such systems, but giant salamanders are a rare exception. Because gigantism entails extreme ontogenetic body size variation, it is expected to drive strong trophic niche shifts and reshape interactions within and among species as individuals grow.

Research Center/Unit :

FOCUS - Freshwater and OCeanic science Unit of reSearch - ULiège

Disciplines :

Environmental sciences & ecology
Zoology
Aquatic sciences & oceanology

Author, co-author :

Duret, Clément ; Université de Liège - ULiège > Freshwater and OCeanic science Unit of reSearch (FOCUS) ; Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Laboratoire d'Écologie et de Conservation des Amphibiens (LECA)

Lejeune, Benjamin ; Université de Liège - ULiège > Freshwater and OCeanic science Unit of reSearch (FOCUS) ; Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Laboratoire d'Écologie et de Conservation des Amphibiens (LECA)

Lepoint, Gilles ; Université de Liège - ULiège > Freshwater and OCeanic science Unit of reSearch (FOCUS) ; Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Laboratoire d'Ecologie trophique et isotopique

Bartet, Tiphanie; Laboratory of Ecology and Conservation of Amphibians (LECA), Freshwater and OCeanic science Unit of reSearch (FOCUS), University of Liège, Liège, Belgium

Okada, Sumio; The Hanzaki Research Institute of Japan, Asago, Japan

Fukushima, Keitaro; Faculty of Food and Agricultural Sciences, Fukushima University, Fukushima City, Fukushima, Japan

Kishida, Osamu; Field Science Center for Northern Biosphere, Wakayama Experimental Forest, Hokkaido University, Sapporo, Japan

Denoël, Mathieu ; Université de Liège - ULiège > Freshwater and OCeanic science Unit of reSearch (FOCUS) ; Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Laboratoire d'Écologie et de Conservation des Amphibiens (LECA)

Language :

English

Title :

When giant amphibians rule the river: Community trophic structure of Japanese giant salamander ecosystems

Publication date :

2026

Journal title :

Ecology

ISSN :

0012-9658

eISSN :

1939-9170

Publisher :

Wiley

Volume :

107

Issue :

Pages :

e70473

Peer reviewed :

Peer Reviewed verified by ORBi

Development Goals :

14. Life below water

Additional URL :

https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/ecy.70473

Funders :

FRIA - Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture
F.R.S.-FNRS - Fonds de la Recherche Scientifique
JSPS - Japan Society for the Promotion of Science
ULiège FSR - Université de Liège. Fonds spéciaux pour la recherche

Funding number :

1.E.058.22F; 22H04983; 22H05644; 23K23957; Topsalamander; Freshwater Predator

Available on ORBi :

since 04 September 2026

Statistics

Number of views

39 (2 by ULiège)

Number of downloads

45 (1 by ULiège)

More statistics

Scopus citations^®

Scopus citations^®
without self-citations

OpenAlex citations

Bibliography

Anaya-Rojas, J. M., R. D. Bassar, B. Matthews, J. F. Goldberg, L. King, D. Reznick, and J. Travis. 2023. “Does the Evolution of Ontogenetic Niche Shifts Favour Species Coexistence? An Empirical Test in Trinidadian Streams.” Journal of Animal Ecology 92: 1601–1612. https://doi.org/10.1111/1365-2656.13912.
Bascompte, J., C. J. Melián, and E. Sala. 2005. “Interaction Strength Combinations and the Overfishing of a Marine Food Web.” Proceedings of the National Academy of Sciences 102: 5443–5447. https://doi.org/10.1073/pnas.0501562102.
Belouard, N., E. J. Petit, J. Cucherousset, and J.-M. Paillisson. 2024. “Variation of the Stable Isotope Niches of Native Amphibians in Ponds Invaded by the Red Swamp Crayfish.” NeoBiota 93: 245–262. https://doi.org/10.3897/neobiota.93.120477.
Bissattini, A. M., P. J. Haubrock, V. Buono, P. Balzani, N. Borgianni, L. Stellati, A. F. Inghilesi, et al. 2021. “Trophic Structure of a Pond Community Dominated by an Invasive Alien Species: Insights from Stomach Content and Stable Isotope Analyses.” Aquatic Conservation: Marine and Freshwater Ecosystems 31: 948–963. https://doi.org/10.1002/aqc.3530.
Bonett, R. M., N. M. Ledbetter, A. J. Hess, M. A. Herrboldt, and M. Denoël. 2022. “Repeated Ecological and Life Cycle Transitions Make Salamanders an Ideal Model for Evolution and Development.” Developmental Dynamics 251: 957–972. https://doi.org/10.1002/dvdy.373.
Brett, M. T., S. E. Bunn, S. Chandra, A. W. E. Galloway, F. Guo, M. J. Kainz, P. Kankaala, et al. 2017. “How Important Are Terrestrial Organic Carbon Inputs for Secondary Production in Freshwater Ecosystems?” Freshwater Biology 62: 833–853. https://doi.org/10.1111/fwb.12909.
Brose, U. 2010. “Body-Mass Constraints on Foraging Behaviour Determine Population and Food-Web Dynamics.” Functional Ecology 24: 28–34. https://doi.org/10.1111/j.1365-2435.2009.01618.x.
Charrad, M., N. Ghazzali, V. Boiteau, and A. Niknafs. 2014. “NbClust: An R Package for Determining the Relevant Number of Clusters in a Data Set.” Journal of Statistical Software 61: 1–36. https://doi.org/10.18637/jss.v061.i06.
Chételat, J., F. R. Pick, A. Morin, and P. B. Hamilton. 1999. “Periphyton Biomass and Community Composition in Rivers of Different Nutrient Status.” Canadian Journal of Fisheries and Aquatic Sciences 56: 560–569. https://doi.org/10.1139/f98-197.
Claessen, D., C. Van Oss, A. M. de Roos, and L. Persson. 2002. “The Impact of Size-Dependent Predation on Population Dynamics and Individual Life History.” Ecology 83: 1660–1675. https://doi.org/10.1890/0012-9658(2002)083[1660:TIOSDP]2.0.CO;2.
Cohen, J. E., T. Jonsson, and S. R. Carpenter. 2003. “Ecological Community Description Using the Food Web, Species Abundance, and Body Size.” Proceedings of the National Academy of Sciences 100: 1781–1786. https://doi.org/10.1073/pnas.232715699.
Cole, J. J., S. R. Carpenter, J. Kitchell, M. L. Pace, C. T. Solomon, and B. Weidel. 2011. “Strong Evidence for Terrestrial Support of Zooplankton in Small Lakes Based on Stable Isotopes of Carbon, Nitrogen, and Hydrogen.” Proceedings of the National Academy of Sciences 108: 1975–1980. https://doi.org/10.1073/pnas.1012807108.
Coplen, T. B. 2011. “Guidelines and Recommended Terms for Expression of Stable-Isotope-Ratio and Gas-Ratio Measurement Results.” Rapid Communications in Mass Spectrometry 25: 2538–2560. https://doi.org/10.1002/rcm.5129.
de Roos, A. M., and L. Persson. 2013. Population and Community Ecology of Ontogenetic Development. Princeton: Princeton University Press.
Denoël, M., and P. Joly. 2001. “Adaptive Significance of Facultative Paedomorphosis in Triturus alpestris (Amphibia, Caudata): Resource Partitioning in an Alpine Lake.” Freshwater Biology 46: 1387–1396. https://doi.org/10.1046/j.1365-2427.2001.00762.x.
Duret, C., T. Bartet, A. Hambuckers, O. Kishida, S. Okada, Y. Taguchi, M. K. Takahashi, and M. Denoël. 2025. “Loss of Habitat Suitability and Distribution Range of the Endangered Japanese Giant Salamander under Climate Change.” Frontiers of Biogeography 18: e133105. https://doi.org/10.21425/fob.18.133105.
Duret, C., B. Lejeune, G. Lepoint, T. Bartet, S. Okada, K. Fukushima, O. Kishida, and M. Denoël. 2026a. “A Giant's Appetite: How Body Size Drives the Diet and Trophic Position of the Japanese Giant Salamander.” Oikos 2026: e11831. https://doi.org/10.1002/oik.11831.
Duret, C., B. Lejeune, G. Lepoint, T. Bartet, S. Okada, K. Fukushima, O. Kishida, and M. Denoël. 2026b. “Data and Code for: When Giant Amphibians Rule the River: Community Trophic Structure of Japanese Giant Salamander Ecosystems [Dataset].” Dryad. https://doi.org/10.5061/dryad.fn2z34v89.
Echeverria, A., S. Botta, M. Marmontel, G. Melo-Santos, P. Fruet, M. Oliveira-da-Costa, M. Pouilly, J. Di Tullio, and P. A. Van Damme. 2022. “Trophic Ecology of Amazonian River Dolphins from Three Rivers in Brazil and Bolivia.” Mammalian Biology 102: 1687–1696. https://doi.org/10.1007/s42991-022-00267-x.
Estes, J. A., J. Terborgh, J. S. Brashares, M. E. Power, J. Berger, W. J. Bond, S. R. Carpenter, et al. 2011. “Trophic Downgrading of Planet Earth.” Science 333: 301–306. https://doi.org/10.1126/science.1205106.
Finlay, J. C., and C. Kendall. 2007. “Stable Isotope Tracing of Temporal and Spatial Variability in Organic Matter Sources to Freshwater Ecosystems.” In Stable Isotopes in Ecology and Environmental Science, 2nd ed., edited by R. Michener and K. Lajtha, 283–333. Oxford: Blackwell Publishing Ltd.
Gao, K.-Q., and N. H. Shubin. 2003. “Earliest Known Crown-Group Salamanders.” Nature 422: 424–428. https://doi.org/10.1038/nature01491.
Hammerschlag, N., O. J. Schmitz, A. S. Flecker, K. D. Lafferty, A. Sih, T. B. Atwood, A. J. Gallagher, D. J. Irschick, R. Skubel, and S. J. Cooke. 2019. “Ecosystem Function and Services of Aquatic Predators in the Anthropocene.” Trends in Ecology & Evolution 34: 369–383. https://doi.org/10.1016/j.tree.2019.01.005.
Hecht, K. A., M. A. Nickerson, and P. B. Colclough. 2017. “Hellbenders (Cryptobranchus alleganiensis) May Exhibit an Ontogenetic Dietary Shift.” Southeastern Naturalist 16: 157–162. https://doi.org/10.1656/058.016.0204.
Heim, N. A., M. L. Knope, E. K. Schaal, S. C. Wang, and J. L. Payne. 2015. “Cope's Rule in the Evolution of Marine Animals.” Science 347: 867–870. https://doi.org/10.1126/science.1260065.
Jackson, A. L., R. Inger, A. C. Parnell, and S. Bearhop. 2011. “Comparing Isotopic Niche Widths Among and Within Communities: SIBER – Stable Isotope Bayesian Ellipses in R.” Journal of Animal Ecology 80: 595–602. https://doi.org/10.1111/j.1365-2656.2011.01806.x.
Jardine, T. D., T. S. Rayner, N. E. Pettit, D. Valdez, D. P. Ward, G. Lindner, M. M. Douglas, and S. E. Bunn. 2017. “Body Size Drives Allochthony in Food Webs of Tropical Rivers.” Oecologia 183: 505–517. https://doi.org/10.1007/s00442-016-3786-z.
Katano, O. 1996. “Foraging Tactics and Home Range of Dark Chub in a Japanese River.” Oecologia 106: 199–205. https://doi.org/10.1007/BF00328599.
Kawai, T., and K. Tanida. 2018. Aquatic Insects of Japan: Manual with Keys and Illustrations, 2nd ed. Kanagawa: Tokai University Press.
Keppeler, F. W., T. Giarrizzo, C. G. Montaña, A. Adite, Ş. Akın, R. Angelini, C. C. Arantes, et al. 2026. “What Determines Trophic Niche Breadth? A Global Analysis of Freshwater Fishes Using Isospaces.” Reviews in Fish Biology and Fisheries 36: 13. https://doi.org/10.1007/s11160-025-10023-2.
Kopf, R. K., S. Banks, L. J. N. Brent, P. Humphries, C. J. Jolly, P. C. Lee, O. J. Luiz, D. Nimmo, and K. O. Winemiller. 2024. “Loss of Earth's Old, Wise, and Large Animals.” Science 387(6729): eado2705. https://doi.org/10.1126/science.ado2705.
Kopf, R. K., L. McPhan, P. J. McInerney, B. Zampatti, J. Thiem, W. Koster, G. L. Butler, N. Bond, and R. M. Thompson. 2025. “Intraspecific Body Size Determines Isotopic Trophic Structure of a Large River Fish Community.” Journal of Animal Ecology 94: 1435–1448. https://doi.org/10.1111/1365-2656.70069.
Layman, C. A., D. A. Arrington, C. G. Montaña, and D. M. Post. 2007. “Can Stable Isotope Ratios Provide for Community-Wide Measures of Trophic Structure?” Ecology 88: 42–48. https://doi.org/10.1890/0012-9658(2007)88[42:CSIRPF]2.0.CO;2.
Lei, J., W. Xiong, X.-Y. Sui, and Y. F. Chen. 2018. “Feeding Habits of the Chinese Minnow Rhynchocypris oxycephalus (Sauvage & Dabry de Thiersant, 1874) from the Upper Yangtze River, China.” Journal of Applied Ichthyology 34: 550–555. https://doi.org/10.1111/jai.13597.
Lejeune, B., L. Bissey, E. A. Didaskalou, N. Sturaro, G. Lepoint, and M. Denoël. 2021. “Progenesis as an Intrinsic Factor of Ecological Opportunity in a Polyphenic Amphibian.” Functional Ecology 35: 546–560. https://doi.org/10.1111/1365-2435.13708.
Lejeune, B., N. Sturaro, G. Lepoint, and M. Denoël. 2018. “Facultative Paedomorphosis as a Mechanism Promoting Intraspecific Niche Differentiation.” Oikos 127: 427–439. https://doi.org/10.1111/oik.04714.
Matsumoto, R., S.-i. Fujiwara, and S. E. Evans. 2024. “The Anatomy and Feeding Mechanism of the Japanese Giant Salamander (Andrias japonicus).” Journal of Anatomy 244: 679–707. https://doi.org/10.1111/joa.14004.
McCauley, D. J., H. S. Young, R. B. Dunbar, J. A. Estes, B. X. Semmens, and F. Micheli. 2012. “Assessing the Effects of Large Mobile Predators on Ecosystem Connectivity.” Ecological Applications 22: 1711–1717. https://doi.org/10.1890/11-1653.1.
McCutchan, J. H., W. M. Lewis, Jr., C. Kendall, and C. C. McGrath. 2003. “Variation in Trophic Shift for Stable Isotope Ratios of Carbon, Nitrogen, and Sulfur.” Oikos 102: 378–390. https://doi.org/10.1034/j.1600-0706.2003.12098.x.
Nakazawa, T. 2015. “Ontogenetic Niche Shifts Matter in Community Ecology: A Review and Future Perspectives.” Population Ecology 57: 347–354. https://doi.org/10.1007/s10144-014-0448-z.
Okada, S., T. Utsunomiya, T. Okada, Z. I. Felix, and F. Ito. 2008. “Characteristics of Japanese Giant Salamander (Andrias japonicus) Populations in Two Small Tributary Streams in Hiroshima Prefecture, Western Honshu, Japan.” Herpetological Conservation and Biology 3: 192–202.
Ou, C., C. G. Montaña, and K. O. Winemiller. 2017. “Body Size–Trophic Position Relationships among Fishes of the Lower Mekong Basin.” Royal Society Open Science 4: 160645. https://doi.org/10.1098/rsos.160645.
Pace, M. L., J. J. Cole, S. R. Carpenter, and J. F. Kitchell. 1999. “Trophic Cascades Revealed in Diverse Ecosystems.” Trends in Ecology & Evolution 14: 483–488. https://doi.org/10.1016/S0169-5347(99)01723-1.
Parnell, A. C., R. Inger, S. Bearhop, and A. L. Jackson. 2010. “Source Partitioning Using Stable Isotopes: Coping with Too Much Variation.” PLoS One 5: e9672. https://doi.org/10.1371/journal.pone.0009672.
Polis, G. A., W. B. Anderson, and R. D. Holt. 1997. “Toward an Integration of Landscape and Food Web Ecology: The Dynamics of Spatially Subsidized Food Webs.” Annual Review of Ecology, Evolution, and Systematics 28: 289–316. https://doi.org/10.1146/annurev.ecolsys.28.1.289.
Post, D. M. 2002. “Using Stable Isotopes to Estimate Trophic Position: Models, Methods, and Assumptions.” Ecology 83: 703–718. https://doi.org/10.1890/0012-9658%282002%29083%5B0703%3AUSITET%5D2.0.CO%3B2.
Quezada-Romegialli, C., A. L. Jackson, B. Hayden, K. K. Kahilainen, C. Lopes, and C. Harrod. 2018. “tRophicPosition, an R Package for the Bayesian Estimation of Trophic Position from Consumer Stable Isotope Ratios.” Methods in Ecology and Evolution 9: 1592–1599. https://doi.org/10.1111/2041-210X.13009.
Radloff, F. G. T., K. A. Hobson, and A. J. Leslie. 2012. “Characterising Ontogenetic Niche Shifts in Nile Crocodile Using Stable Isotope (δ13C, δ15N) Analyses of Scute Keratin.” Isotopes in Environmental and Health Studies 48: 439–456. https://doi.org/10.1080/10256016.2012.667808.
Rejas, D., T. Oberdorff, S. A. J. Declerck, and M. Winder. 2023. “The Introduced Arapaima gigas in the Bolivian Amazon: Trophic Position and Isotopic Niche Overlap with Native Species.” Ecology of Freshwater Fish 32: 926–937. https://doi.org/10.1111/eff.12734.
Ripple, W. J., J. A. Estes, R. L. Beschta, C. C. Wilmers, E. G. Ritchie, M. Hebblewhite, J. Berger, et al. 2014. “Status and Ecological Effects of the World's Largest Carnivores.” Science 343: 1241484. https://doi.org/10.1126/science.1241484.
Rodríguez-Lozano, P., I. Verkaik, M. Rieradevall, and N. Prat. 2015. “Small but Powerful: Top Predator Local Extinction Affects Ecosystem Structure and Function in an Intermittent Stream.” PLoS One 10: e0117630. https://doi.org/10.1371/journal.pone.0117630.
Rooney, N., K. McCann, G. Gellner, and J. C. Moore. 2006. “Structural Asymmetry and the Stability of Diverse Food Webs.” Nature 442: 265–269. https://doi.org/10.1038/nature04887.
Santos, X., S. Navarro, J. C. Campos, C. Sanpera, and J. C. Brito. 2018. “Stable Isotopes Uncover Trophic Ecology of the West African Crocodile (Crocodylus suchus).” Journal of Arid Environments 148: 6–13. https://doi.org/10.1016/j.jaridenv.2017.09.008.
Tago, K. 1931. “The Salamanders of Japan.” Geisho-Do (in Japanese).
Tochimoto, T. 2002. “Studies of the Japanese Giant Salamanders. X. Food Habits I.” Hyogo Biology 12: 134–139 (in Japanese).
Unger, S. D., L. A. Williams, L. Diaz, and C. B. Jachowski. 2020. “DNA Barcoding to Assess Diet of Larval Eastern Hellbenders in North Carolina.” Food Webs 22: e00134. https://doi.org/10.1016/j.fooweb.2019.e00134.
van Leeuwen, A., M. Huss, A. Gårdmark, and A. M. de Roos. 2014. “Ontogenetic Specialism in Predators with Multiple Niche Shifts Prevents Predator Population Recovery and Establishment.” Ecology 95: 2409–2422. https://doi.org/10.1890/13-0843.1.
Vannote, R. L., G. W. Minshall, K. W. Cummins, J. R. Sedell, and C. E. Cushing. 1980. “The River Continuum Concept.” Canadian Journal of Fisheries and Aquatic Sciences 37: 130–137. https://doi.org/10.1139/f80-017.
Vermeij, G. J. 2012. “The Evolution of Gigantism on Temperate Seashores.” Biological Journal of the Linnean Society 106: 776–793. https://doi.org/10.1111/j.1095-8312.2012.01897.x.
Vermeij, G. J. 2016. “Gigantism and Its Implications for the History of Life.” PLoS One 11: e0146092. https://doi.org/10.1371/journal.pone.0146092.
Villamarín, F., T. D. Jardine, S. E. Bunn, A. Malvasio, C. I. Piña, C. M. Jacobi, D. D. Araújo, et al. 2024. “Body Size Predicts Ontogenetic Nitrogen Stable-Isotope (δ15N) Variation, but Has Little Relationship with Trophic Level in Ectotherm Vertebrate Predators.” Scientific Reports 14: 14102. https://doi.org/10.1038/s41598-024-61969-5.
Villamarín, F., T. D. Jardine, S. E. Bunn, B. Marioni, and W. E. Magnusson. 2017. “Opportunistic Top Predators Partition Food Resources in a Tropical Freshwater Ecosystem.” Freshwater Biology 62: 1389–1400. https://doi.org/10.1111/fwb.12952.
Villamarín, F., T. D. Jardine, S. E. Bunn, B. Marioni, and W. E. Magnusson. 2018. “Body Size Is More Important than Diet in Determining Stable-Isotope Estimates of Trophic Position in Crocodilians.” Scientific Reports 8: 2020. https://doi.org/10.1038/s41598-018-19918-6.
Werner, E. E., and J. F. Gilliam. 1984. “The Ontogenetic Niche and Species Interactions in Size-Structured Populations.” Annual Review of Ecology and Systematics 15: 393–425.
Wilbur, H. M. 1980. “Complex Life Cycles.” Annual Review of Ecology and Systematics 11: 67–93.
Williams, T. M., J. A. Estes, D. F. Doak, and A. M. Springer. 2004. “Killer Appetites: Assessing the Role of Predators in Ecological Communities.” Ecology 85: 3373–3384. https://doi.org/10.1890/03-0696.
Woodward, G., B. Ebenman, M. C. Emmerson, J. M. Montoya, J. M. Olesen, A. Valido, P. H. Warren, P. C. de Ruiter, V. Wolters, and J. C. Moore. 2005. “Body Size Determinants of the Structure of and Dynamics of Ecological Networks: Scaling from the Individual to the Ecosystem.” In Dynamic Food Webs – Multispecies Assemblages, Ecosystem Development and Environmental Change, edited by P. C. de Ruiter, V. Wolters, and J. C. Moore, 179–197. Amsterdam: Elsevier.
Woodward, G., and A. G. Hildrew. 2002. “Food Web Structure in Riverine Landscapes.” Freshwater Biology 47: 777–798. https://doi.org/10.1046/j.1365-2427.2002.00908.x.