{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T00:39:24Z","timestamp":1792543164672,"version":"4.5.0"},"reference-count":55,"publisher":"The Royal Society","issue":"10","license":[{"start":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T00:00:00Z","timestamp":1792540800000},"content-version":"vor","delay-in-days":14,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100023581","name":"National Science Foundation (NSF) Graduate Research Fellowship Program","doi-asserted-by":"publisher","award":["2035702"],"award-info":[{"award-number":["2035702"]}],"id":[{"id":"10.13039\/100023581","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000001","name":"NSF","doi-asserted-by":"publisher","award":["DEB\u20131146374"],"award-info":[{"award-number":["DEB\u20131146374"]}],"id":[{"id":"10.13039\/100000001","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,10,7]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Low body condition can promote risky foraging, but whether condition dependence differs across life stages remains unclear. Using field and laboratory studies, we tested whether residual body condition (RBC) predicted foraging under moonlight-mediated predation risk in the Amazonian sand knifefish, Gymnorhamphichthys rondoni. This species has a 2-year lifespan and a single late second-year breeding season. Because adults have less time than juveniles to recover condition before breeding, we predicted stronger condition dependence in adults. Among wild fish pooled across life stages, stomach fullness increased overnight on dark (lower-risk) but not bright moonlit (higher-risk) nights, when most stomachs were empty and non-empty stomachs occurred mainly in low-RBC fish. In experiments under laboratory-recreated moonlight, lower-RBC adults were active longer than higher-RBC adults on full-moon nights, as quantified by electric organ discharge rate. RBC did not predict adult activity on new-moon nights or juvenile activity on full- or new-moon nights. A full-moon interaction model showed a significantly stronger RBC\u2013activity relationship in adults than in juveniles. In light-ramping trials, lower-RBC adults remained active at higher illuminance before hiding, whereas most juveniles did not hide. Our results are consistent with the asset-protection prediction of stronger condition-dependent risk-taking in adults facing late-life constraints than in juveniles.<\/jats:p>","DOI":"10.1098\/rsos.260914","type":"journal-article","created":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T00:12:52Z","timestamp":1792541572000},"source":"Crossref","is-referenced-by-count":0,"title":["Life stage shapes condition-dependent foraging under predation risk in an electric fish"],"prefix":"10.1098","volume":"13","author":[{"given":"Lok","family":"Poon","sequence":"first","affiliation":[{"name":"Department of Biology, University of Central Florida , Orlando, FL 32816, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2892-8065","authenticated-orcid":false,"given":"William G. R.","family":"Crampton","sequence":"additional","affiliation":[{"name":"Department of Biology, University of Central Florida , Orlando, FL 32816, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"175","published-online":{"date-parts":[[2026,10,21]]},"reference":[{"key":"2026102020124723400_RSOS260914C1","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1038\/380215a0","article-title":"State-dependent life histories","volume":"380","author":"McNamara","year":"1996","journal-title":"Nature"},{"key":"2026102020124723400_RSOS260914C2","first-page":"20180180","article-title":"State-dependent risk-taking","volume-title":"Proc. R. Soc. B","author":"Barclay","year":"2018"},{"key":"2026102020124723400_RSOS260914C3","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1111\/brv.13011","article-title":"A general framework for modelling trade-offs in adaptive behaviour","volume":"99","author":"Houston","year":"2024","journal-title":"Biol. Rev."},{"key":"2026102020124723400_RSOS260914C4","volume-title":"Models of adaptive behaviour: an approach based on state","author":"Houston","year":"1999"},{"key":"2026102020124723400_RSOS260914C5","doi-asserted-by":"crossref","first-page":"1364","DOI":"10.1111\/ele.12832","article-title":"A \u2018dynamic\u2019 landscape of fear: prey responses to spatiotemporal variations in predation risk across the lunar cycle","volume":"20","author":"Palmer","year":"2017","journal-title":"Ecol. Lett."},{"key":"2026102020124723400_RSOS260914C6","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1111\/eth.70030","article-title":"Condition-dependent responses to risk in a small mammal","volume":"132","author":"Lopez-Hervas","year":"2026","journal-title":"Ethology"},{"key":"2026102020124723400_RSOS260914C7","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1007\/BF02464838","article-title":"Risk-sensitive foraging: a review of the theory","volume":"54","author":"McNamara","year":"1992","journal-title":"Bull. Math. Biol."},{"key":"2026102020124723400_RSOS260914C8","doi-asserted-by":"crossref","first-page":"e03660","DOI":"10.1002\/ecs2.3660","article-title":"Survival of the fattest: linking body condition to prey availability and survivorship of killer whales","volume":"12","author":"Stewart","year":"2021","journal-title":"Ecosphere"},{"key":"2026102020124723400_RSOS260914C9","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.fishres.2019.03.013","article-title":"The utility of length, age, liver condition, and body condition for predicting maturity and fecundity of female sablefish","volume":"216","author":"Rodgveller","year":"2019","journal-title":"Fish. Res."},{"key":"2026102020124723400_RSOS260914C10","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1093\/beheco\/5.2.159","article-title":"Antipredator behavior and the asset-protection principle","volume":"5","author":"Clark","year":"1994","journal-title":"Behav. Ecol."},{"key":"2026102020124723400_RSOS260914C11","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1007\/s00442-019-04395-z","article-title":"State-dependent foraging among social fish in a risky environment","volume":"190","author":"Balaban-Feld","year":"2019","journal-title":"Oecologia"},{"key":"2026102020124723400_RSOS260914C12","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1111\/brv.12655","article-title":"Poor nutritional condition promotes high-risk behaviours: a systematic review and meta-analysis","volume":"96","author":"Moran","year":"2021","journal-title":"Biol. Rev."},{"key":"2026102020124723400_RSOS260914C13","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1006\/anbe.1996.0151","article-title":"Predation risk and state-dependent foraging in scorpions: effects of moonlight on foraging in the scorpion Buthus occitanus","volume":"52","author":"Skutelsky","year":"1996","journal-title":"Anim. Behav."},{"key":"2026102020124723400_RSOS260914C14","first-page":"1443","article-title":"Ontogeny of energy allocation reveals selective pressure promoting risk-taking behaviour in young fish cohorts","volume-title":"Proc. R. Soc. B","author":"Biro","year":"2005"},{"key":"2026102020124723400_RSOS260914C15","doi-asserted-by":"crossref","first-page":"15","DOI":"10.1016\/0169-5347(92)90192-E","article-title":"Optimal allocation of resources to growth and reproduction: implications for age and size at maturity","volume":"7","author":"Koz\u0142owski","year":"1992","journal-title":"Trends Ecol. Evol."},{"key":"2026102020124723400_RSOS260914C16","doi-asserted-by":"crossref","first-page":"686","DOI":"10.1086\/285069","article-title":"Life-history strategies for energy gain and predator avoidance under time constraints","volume":"135","author":"Ludwig","year":"1990","journal-title":"Am. Nat."},{"key":"2026102020124723400_RSOS260914C17","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1093\/cz\/zoy091","article-title":"Ontogenetic shifts in perceptions of safety along structural complexity gradients in a territorial damselfish","volume":"65","author":"Chan","year":"2019","journal-title":"Curr. Zool."},{"key":"2026102020124723400_RSOS260914C18","doi-asserted-by":"crossref","first-page":"1242","DOI":"10.2307\/1941098","article-title":"Life history and the relationship between food availability and foraging effort","volume":"72","author":"Abrams","year":"1991","journal-title":"Ecology"},{"key":"2026102020124723400_RSOS260914C19","doi-asserted-by":"crossref","first-page":"1081","DOI":"10.1111\/j.1095-8649.2001.tb00173.x","article-title":"Association between growth, body condition and anti-predator behaviour in maturing and immature brown trout parr","volume":"59","author":"Dannewitz","year":"2001","journal-title":"J. Fish Biol."},{"key":"2026102020124723400_RSOS260914C20","doi-asserted-by":"crossref","first-page":"535","DOI":"10.1006\/anbe.1999.1345","article-title":"Antipredator vigilance of juvenile and adult thirteen-lined ground squirrels and the role of nutritional need","volume":"59","author":"Arenz","year":"2000","journal-title":"Anim. Behav."},{"key":"2026102020124723400_RSOS260914C21","doi-asserted-by":"crossref","first-page":"867","DOI":"10.2307\/1940164","article-title":"Size-related effects of predation on habitat use and behavior of porcupines (Erethizon dorsatum)","volume":"73","author":"Sweitzer","year":"1992","journal-title":"Ecology"},{"key":"2026102020124723400_RSOS260914C22","doi-asserted-by":"crossref","first-page":"e70133","DOI":"10.1002\/ecy.70133","article-title":"A sensory ecology of fear: eye size predicts moonlight avoidance responses in neotropical electric fishes","volume":"106","author":"Poon","year":"2025","journal-title":"Ecology"},{"key":"2026102020124723400_RSOS260914C23","doi-asserted-by":"crossref","first-page":"e190006","DOI":"10.1590\/1982-0224-20190006","article-title":"Spatial and temporal distribution of Gymnorhamphichthys rondoni (Gymnotiformes: Rhamphichthyidae) in a long-term study of an Amazonian terra firme stream, Leticia\u2013Colombia","volume":"17","author":"Escamilla-Pinilla","year":"2019","journal-title":"Neotrop. Ichthyol."},{"key":"2026102020124723400_RSOS260914C24","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1007\/BF00299291","article-title":"Activity rhythm of an electric fish, Gymnorhamphichthys hypostomus, Ellis","volume":"51","author":"Lissmann","year":"1965","journal-title":"Z. Vgl. Physiol."},{"key":"2026102020124723400_RSOS260914C25","first-page":"187","volume-title":"Rhythmic activity of fishes","author":"Schwassmann","year":"1978"},{"key":"2026102020124723400_RSOS260914C26","doi-asserted-by":"crossref","first-page":"20250704","DOI":"10.1098\/rsbl.2025.0704","article-title":"Timescapes of fear: exogenous and endogenous control of moonlight-mediated circalunar foraging rhythms in a weakly electric fish","volume":"22","author":"Poon","year":"2026","journal-title":"Biol. Lett."},{"key":"2026102020124723400_RSOS260914C27","doi-asserted-by":"crossref","first-page":"233","DOI":"10.1006\/anbe.1993.1185","article-title":"The effect of body condition on the trade-off between vigilance and foraging in Belding's ground squirrels","volume":"46","author":"Bachman","year":"1993","journal-title":"Anim. Behav."},{"key":"2026102020124723400_RSOS260914C28","doi-asserted-by":"crossref","first-page":"917","DOI":"10.1890\/03-3002","article-title":"Apprehension and time allocation in gerbils: the effects of predatory risk and energetic state","volume":"85","author":"Kotler","year":"2004","journal-title":"Ecology"},{"key":"2026102020124723400_RSOS260914C29","doi-asserted-by":"crossref","first-page":"1799","DOI":"10.1890\/10-2222.1","article-title":"The effects of variable predation risk on foraging and growth: less risk is not necessarily better","volume":"92","author":"Trussell","year":"2011","journal-title":"Ecology"},{"key":"2026102020124723400_RSOS260914C30","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1111\/jfb.13922","article-title":"Electroreception, electrogenesis and electric signal evolution","volume":"95","author":"Crampton","year":"2019","journal-title":"J. Fish Biol."},{"key":"2026102020124723400_RSOS260914C31","unstructured":"Garcia\n              EQ\n            \n          . 2019Biologia e uso de h\u00e1bitat por Gymnorhamphichthys rondoni (Rhamphichthyidae: Gymnotiformes). PhD thesis, Instituto Nacional de Pesquisas da Amaz\u00f4nia, Manaus, Brazil."},{"key":"2026102020124723400_RSOS260914C32","doi-asserted-by":"crossref","first-page":"e1499","DOI":"10.1002\/ecm.1499","article-title":"Reproductive effort and terminal investment in a multispecies assemblage of Amazon electric fish","volume":"92","author":"Waddell","year":"2022","journal-title":"Ecol. Monogr."},{"key":"2026102020124723400_RSOS260914C33","doi-asserted-by":"crossref","first-page":"1183","DOI":"10.1111\/jfb.12213","article-title":"Risk-taking behaviour may explain high predation mortality of GH-transgenic common carp Cyprinus carpio","volume":"83","author":"Duan","year":"2013","journal-title":"J. Fish Biol."},{"key":"2026102020124723400_RSOS260914C34","doi-asserted-by":"crossref","first-page":"896","DOI":"10.1046\/j.1365-2656.2000.00432.x","article-title":"Increased risk of predation as a cost of high growth rate: an experimental test in a butterfly","volume":"69","author":"Gotthard","year":"2000","journal-title":"J. Anim. Ecol."},{"key":"2026102020124723400_RSOS260914C35","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1146\/annurev.es.15.110184.002141","article-title":"The ontogenetic niche and species interactions in size-structured populations","volume":"15","author":"Werner","year":"1984","journal-title":"Annu. Rev. Ecol. Syst."},{"key":"2026102020124723400_RSOS260914C36","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1086\/285857","article-title":"The effect of flexible growth rates on optimal sizes and development times in a seasonal environment","volume":"147","author":"Abrams","year":"1996","journal-title":"Am. Nat."},{"key":"2026102020124723400_RSOS260914C37","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1111\/j.1600-0633.1994.tb00102.x","article-title":"The cost of early maturation on growth, body condition and somatic lipid content in a lake pumpkinseed (Lepomis gibbosus) population","volume":"3","author":"Justus","year":"1994","journal-title":"Ecol. Freshw. Fish"},{"key":"2026102020124723400_RSOS260914C38","doi-asserted-by":"crossref","first-page":"e09967","DOI":"10.1111\/oik.09967","article-title":"Geomorphological habitat type drives variation in temporal species turnover but not temporal nestedness in Amazonian fish assemblages","volume":"2023","author":"Bogot\u00e1-Gregory","year":"2023","journal-title":"Oikos"},{"key":"2026102020124723400_RSOS260914C39","doi-asserted-by":"crossref","first-page":"149","DOI":"10.2307\/3544860","article-title":"Predicting risk-taking behaviour from life-history theory using static optimization technique","volume":"60","author":"Leonardsson","year":"1991","journal-title":"Oikos"},{"key":"2026102020124723400_RSOS260914C40","doi-asserted-by":"crossref","first-page":"16280","DOI":"10.1002\/ece3.8311","article-title":"Grow fast, die young: does compensatory growth reduce survival of juvenile blacktip sharks (Carcharhinus limbatus) in the western Gulf of Mexico?","volume":"11","author":"Matich","year":"2021","journal-title":"Ecol. Evol."},{"key":"2026102020124723400_RSOS260914C41","first-page":"741","article-title":"The influence of juvenile and adult environments on life-history trajectories","volume-title":"Proc. R. Soc. B","author":"Taborsky","year":"2006"},{"key":"2026102020124723400_RSOS260914C42","unstructured":"Rold\u00e1n\n              EV\n            \n          . 2019Environmental correlates of sensory sampling rate in the electrosensory system of neotropical electric fishes. Masters thesis, University of Central Florida, Orlando, USA."},{"key":"2026102020124723400_RSOS260914C43","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1111\/2041-210X.14299","article-title":"MoonShine: a software-hardware system for simulating moonlight ground illuminance and re-creating artificial moonlight cycles in a laboratory environment","volume":"15","author":"Poon","year":"2024","journal-title":"Methods Ecol. Evol."},{"key":"2026102020124723400_RSOS260914C44","doi-asserted-by":"crossref","first-page":"e190099","DOI":"10.1590\/1982-0224-20190099","article-title":"A new and improved electric fish finder with resources for printed circuit board fabrication","volume":"17","author":"Haag","year":"2019","journal-title":"Neotrop. Ichthyol."},{"key":"2026102020124723400_RSOS260914C45","first-page":"155","article-title":"On-going research activities on trophic ecology of swordfish (Xiphias gladius) in the western Indian Ocean","volume":"4","author":"Marsac","year":"2001","journal-title":"IOTC Proceedings"},{"key":"2026102020124723400_RSOS260914C46","doi-asserted-by":"crossref","first-page":"110860","DOI":"10.1016\/j.ecolind.2023.110860","article-title":"Fish morphometric body condition indices reflect energy reserves but other physiological processes matter","volume":"154","author":"Brosset","year":"2023","journal-title":"Ecol. Indic."},{"key":"2026102020124723400_RSOS260914C47","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1080\/19425120.2011.555724","article-title":"A standardized terminology for describing reproductive development in fishes","volume":"3","author":"Brown-Peterson","year":"2011","journal-title":"Mar. Coast. Fish."},{"key":"2026102020124723400_RSOS260914C48","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1016\/S0921-8009(03)00167-8","article-title":"Environmental constraints and sigmoid utility: implications for value, risk sensitivity, and social status","volume":"46","author":"Kuznar","year":"2003","journal-title":"Ecol. Econ."},{"key":"2026102020124723400_RSOS260914C49","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1016\/j.jtbi.2007.03.029","article-title":"State-dependent choice and ecological rationality","volume":"247","author":"Nevai","year":"2007","journal-title":"J. Theor. Biol."},{"key":"2026102020124723400_RSOS260914C50","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1038\/s42003-026-09588-w","article-title":"Co-variation and trade-offs in ontogenetic scaling of growth and metabolic rates in teleost fish","volume":"9","author":"Ros\u00e9n","year":"2026","journal-title":"Commun. Biol."},{"key":"2026102020124723400_RSOS260914C51","doi-asserted-by":"crossref","first-page":"15349","DOI":"10.1038\/s41598-020-72349-0","article-title":"Biogeochemical water type influences community composition, species richness, and biomass in megadiverse Amazonian fish assemblages","volume":"10","author":"Bogot\u00e1-Gregory","year":"2020","journal-title":"Sci. Rep."},{"key":"2026102020124723400_RSOS260914C52","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1016\/S0169-5347(01)02124-3","article-title":"Compensation for a bad start: grow now, pay later?","volume":"16","author":"Metcalfe","year":"2001","journal-title":"Trends Ecol. Evol."},{"key":"2026102020124723400_RSOS260914C53","doi-asserted-by":"crossref","first-page":"1621","DOI":"10.1016\/j.cub.2026.02.026","article-title":"Electric stealth through bidirectional signal suppression in electric eels and their knifefish prey","volume":"36","author":"Poon","year":"2026","journal-title":"Curr. Biol."},{"key":"2026102020124723400_RSOS260914C54","article-title":"Life stage shapes condition-dependent foraging under predation risk in an electric fish","author":"Poon","year":"2026"},{"key":"2026102020124723400_RSOS260914C55","article-title":"Supplementary material from: Life stage shapes condition-dependent foraging under predation risk in an electric fish","author":"Poon","year":"2026"}],"container-title":["Royal Society Open Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/royalsocietypublishing.org\/rsos\/article-pdf\/doi\/10.1098\/rsos.260914\/6172492\/rsos.260914.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/royalsocietypublishing.org\/rsos\/article-pdf\/doi\/10.1098\/rsos.260914\/6172492\/rsos.260914.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T00:12:59Z","timestamp":1792541579000},"score":1,"resource":{"primary":{"URL":"https:\/\/royalsocietypublishing.org\/rsos\/article\/13\/10\/260914\/483805\/Life-stage-shapes-condition-dependent-foraging"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,7]]},"references-count":55,"journal-issue":{"issue":"10","published-print":{"date-parts":[[2026,10,7]]}},"URL":"https:\/\/doi.org\/10.1098\/rsos.260914","relation":{},"ISSN":["2054-5703"],"issn-type":[{"value":"2054-5703","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,7]]},"article-number":"260914"}}