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Bastos RF, Condini MV, Barbosa EF, Oliveira RL, Almeida LL, Garcia AM, Hostim-Silva M. Seeing further into the early steps of the endangered atlantic goliath grouper (Epinephelus itajara): Eye lenses high resolution isotopic profiles reveal ontogenetic trophic and habitat shifts. MARINE ENVIRONMENTAL RESEARCH 2024; 198:106517. [PMID: 38657369 DOI: 10.1016/j.marenvres.2024.106517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 04/12/2024] [Accepted: 04/15/2024] [Indexed: 04/26/2024]
Abstract
Estuarine mangroves are often considered nurseries for the Atlantic Goliath grouper juveniles. Yet, the contributions of different estuarine primary producers and habitats as sources of organic matter during early ontogenetic development remain unclear. Given the species' critically endangered status and protection in Brazil, obtaining biological samples from recently settled recruits in estuaries is challenging. In this study, we leveraged a local partnership with fishers and used stable isotope (C and N) profiles from the eye lenses of stranded individuals or incidentally caught by fishery to reconstruct the trophic and habitat changes of small juveniles. The eye lens grows by the apposition of protein-rich layers. Once these layers are formed, they become inert, allowing to make inferences on the trophic ecology and habitat use along the development of the individual until its capture. We used correlations between fish size and the entire eye lens size, along with estuarine baselines, to reconstruct the fish size and trophic positions for each of the lens layers obtained. We then used dominant primary producers and basal sources from mangrove sheltered, exposed estuarine and marine habitats to construct an ontogenetic model of trophic and habitat support changes since maternal origins. Our model revealed marine support before the juveniles reached 25 mm (standard length), followed by a rapid increase in reliance on mangrove sheltered sources, coinciding with the expected size at settlement. After reaching 60 mm, individuals began to show variability. Some remained primarily supported by the mangrove sheltered area, while others shifted to rely more on the exposed estuarine area around 150 mm. Our findings indicate that while mangroves are critical for settlement, as Goliath grouper juveniles grow, they can utilize organic matter produced throughout the estuary. This underscores the need for conservation strategies that focus on seascape connectivity, as protecting just one discrete habitat may not be sufficient to preserve this endangered species and safeguard its ecosystem functions.
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Affiliation(s)
- Rodrigo F Bastos
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Programa de Pós-graduação Em Oceanografia Ambiental, Universidade Federal Do Espírito Santo - Av. Fernando Ferrari, 514 - Goiabeiras, Vitória, ES, 29075-910, Brazil.
| | - Mario V Condini
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Programa de Pós-graduação Em Oceanografia Ambiental, Universidade Federal Do Espírito Santo - Av. Fernando Ferrari, 514 - Goiabeiras, Vitória, ES, 29075-910, Brazil
| | - Ester F Barbosa
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil
| | - Rafael L Oliveira
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Programa de Pós-Graduação Em Ciências Biológicas (Biologia Animal - PPGBAN), Departamento de Ciências Biológicas, Universidade Federal Do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil
| | - Lorena L Almeida
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Instituto Meros Do Brasil, Rua Benjamin Constant 67, Conj. 1104, CEP: 80060-020, Curitiba, PR, Brazil
| | - Alexandre M Garcia
- Laboratório de Ictiologia, Instituto de Oceanografia, Universidade Federal Do Rio Grande, Av. Itália Km 8, Carreiros. 96.201-900, Rio Grande, RS, Brazil
| | - Maurício Hostim-Silva
- Laboratório de Ecologia de Peixes Marinhos/LEPMAR, Departamento de Ciências Agrárias e Biológicas, CEUNES, Universidade Federal do Espírito Santo, BR-101, Km 60, Litorâneo, São Mateus, ES, 29932-540, Brazil; Programa de Pós-graduação Em Oceanografia Ambiental, Universidade Federal Do Espírito Santo - Av. Fernando Ferrari, 514 - Goiabeiras, Vitória, ES, 29075-910, Brazil; Programa de Pós-Graduação Em Ciências Biológicas (Biologia Animal - PPGBAN), Departamento de Ciências Biológicas, Universidade Federal Do Espírito Santo, Av. Fernando Ferrari, 514, Goiabeiras, CEP: 29055-460, Vitória, ES, Brazil; Instituto Meros Do Brasil, Rua Benjamin Constant 67, Conj. 1104, CEP: 80060-020, Curitiba, PR, Brazil
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Song A, Liang S, Li H, Yan B. Effects of biodiversity on functional stability of freshwater wetlands: a systematic review. Front Microbiol 2024; 15:1397683. [PMID: 38650885 PMCID: PMC11033414 DOI: 10.3389/fmicb.2024.1397683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 03/27/2024] [Indexed: 04/25/2024] Open
Abstract
Freshwater wetlands are the wetland ecosystems surrounded by freshwater, which are at the interface of terrestrial and freshwater ecosystems, and are rich in ecological composition and function. Biodiversity in freshwater wetlands plays a key role in maintaining the stability of their habitat functions. Due to anthropogenic interference and global change, the biodiversity of freshwater wetlands decreases, which in turn destroys the habitat function of freshwater wetlands and leads to serious degradation of wetlands. An in-depth understanding of the effects of biodiversity on the stability of habitat function and its regulation in freshwater wetlands is crucial for wetland conservation. Therefore, this paper reviews the environmental drivers of habitat function stability in freshwater wetlands, explores the effects of plant diversity and microbial diversity on habitat function stability, reveals the impacts and mechanisms of habitat changes on biodiversity, and further proposes an outlook for freshwater wetland research. This paper provides an important reference for freshwater wetland conservation and its habitat function enhancement.
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Affiliation(s)
- Aiwen Song
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shen Liang
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Huai Li
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
| | - Baixing Yan
- State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
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Guo F, Fry B, Yan K, Huang J, Zhao Q, O'Mara K, Li F, Gao W, Kainz MJ, Brett MT, Bunn SE, Zhang Y. Assessment of the impact of dams on aquatic food webs using stable isotopes: Current progress and future challenges. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:167097. [PMID: 37716688 DOI: 10.1016/j.scitotenv.2023.167097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/10/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
Dams have disrupted natural river systems worldwide and although population and community level effects on aquatic biota have been well documented, food web responses remain poorly understood and difficult to characterize. The application of stable isotope analysis (SIA) provides a means to assess the effect of dams on food webs. Here we review the effect of dams on aquatic food webs using SIA, aiming to detect knowledge gaps in the field of dam impacts on aquatic food webs and propose a conceptual framework to help formulate hypotheses about dam impacts on food webs guided by food web theory. Dams can affect aquatic food webs via two pathways: a bottom-up pathway with altered basal food sources and their transfer to consumers through changes in flow, nutrients, temperature and sediment, and a top-down pathway with consumer species composition altered mainly through habitat fragmentation and related physiochemical changes. Taking these mechanisms into consideration, the impact of dams on food web attributes derived from SIA was evaluated. These studies generally apply mixing models to determine how dams alter the dominant carbon sources supporting food webs, use δ15N to examine how dams alter food-chain length, or use Layman metrics of isotope variability to assess niche changes for invertebrate and fish assemblages. Most studies compare the patterns of SIA metrics spatially (e.g. upstream vs reservoir vs downstream of dams; regulated vs unregulated rivers) and temporally (before vs after dam construction), without explicit hypotheses and/or links to theoretical concepts of food webs. We propose several steps to make SIA studies of dam impacts more rigorous and enhance their potential for producing novel insights. Future studies should quantify the shape and strength of the effect of dams on SIA-measured food web response, be conducted at larger temporal and spatial scales (particularly along the river longitudinal continuum and the lateral connected ecosystems (e.g., floodplains)), and consider effects of dams on food web resilience and tipping points.
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Affiliation(s)
- Fen Guo
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China.
| | - Brian Fry
- Australian Rivers Institute, Griffith University, Nathan, Qld 4109, Australia
| | - Keheng Yan
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Juan Huang
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Qian Zhao
- Institute of Environment and Ecology, Shandong Normal University, Jinan 250358, China
| | - Kaitlyn O'Mara
- Australian Rivers Institute, Griffith University, Nathan, Qld 4109, Australia
| | - Feilong Li
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Wei Gao
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
| | - Martin J Kainz
- WasserCluster Lunz - Inter-University Centre for Aquatic Ecosystem Research, Lunz am See, Austria
| | - Michael T Brett
- Department of Civil and Environmental Engineering, University of Washington, Seattle, WA, USA
| | - Stuart E Bunn
- Australian Rivers Institute, Griffith University, Nathan, Qld 4109, Australia
| | - Yuan Zhang
- Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, China
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Chejanovski ZA, Giery ST, Kolbe JJ. Effects of urbanization on the trophic niche of the brown anole, a widespread invasive lizard. FOOD WEBS 2022. [DOI: 10.1016/j.fooweb.2022.e00257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Riesch R, Araújo MS, Bumgarner S, Filla C, Pennafort L, Goins TR, Lucion D, Makowicz AM, Martin RA, Pirroni S, Langerhans RB. Resource competition explains rare cannibalism in the wild in livebearing fishes. Ecol Evol 2022; 12:e8872. [PMID: 35600676 PMCID: PMC9109233 DOI: 10.1002/ece3.8872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 03/10/2022] [Accepted: 04/12/2022] [Indexed: 11/10/2022] Open
Affiliation(s)
- Rüdiger Riesch
- Department of Biological Sciences Centre for Ecology, Evolution and Behaviour Royal Holloway University of London Egham UK
| | - Márcio S. Araújo
- Instituto de Biociências Universidade Estadual Paulista (UNESP) Rio Claro Brazil
| | - Stuart Bumgarner
- Department of Biological Sciences North Carolina State University Raleigh North Carolina USA
| | - Caitlynn Filla
- Department of Biological Sciences North Carolina State University Raleigh North Carolina USA
- Department of Anthropology University of Florida Gainesville Florida USA
| | - Laura Pennafort
- Department of Biological Sciences Centre for Ecology, Evolution and Behaviour Royal Holloway University of London Egham UK
| | - Taylor R. Goins
- Department of Biological Sciences North Carolina State University Raleigh North Carolina USA
| | - Darlene Lucion
- Department of Biological Sciences Centre for Ecology, Evolution and Behaviour Royal Holloway University of London Egham UK
| | - Amber M. Makowicz
- Department of Biological Sciences Florida State University Tallahassee Florida USA
| | - Ryan A. Martin
- Department of Biology Case Western Reserve University Cleveland Ohio USA
| | - Sara Pirroni
- Department of Biological Sciences Centre for Ecology, Evolution and Behaviour Royal Holloway University of London Egham UK
| | - R. Brian Langerhans
- Department of Biological Sciences North Carolina State University Raleigh North Carolina USA
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6
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Alp M, Cucherousset J. Food webs speak of human impact: Using stable isotope-based tools to measure ecological consequences of environmental change. FOOD WEBS 2022. [DOI: 10.1016/j.fooweb.2021.e00218] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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7
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Santos RO, James WR, Nelson JA, Rehage JS, Serafy J, Pittman SJ, Lirman D. Influence of seascape spatial pattern on the trophic niche of an omnivorous fish. Ecosphere 2022. [DOI: 10.1002/ecs2.3944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Rolando O. Santos
- Institute of Environment Florida International University Miami Florida USA
- Department of Biological Sciences Florida International University Miami Florida USA
| | - W. Ryan James
- Institute of Environment Florida International University Miami Florida USA
- Department of Biological Sciences Florida International University Miami Florida USA
- Department of Earth and Environment Florida International University Miami Florida USA
| | - James A. Nelson
- Department of Biology University of Louisiana Lafayette Louisiana USA
| | - Jennifer S. Rehage
- Institute of Environment Florida International University Miami Florida USA
- Department of Earth and Environment Florida International University Miami Florida USA
| | - Joseph Serafy
- NOAA, National Marine Fisheries Service Southeast Fisheries Science Center Miami Florida USA
- Rosenstiel School of Marine and Atmospheric Science University of Miami Miami Florida USA
| | - Simon J. Pittman
- Oxford Seascape Ecology Lab, School of Geography and the Environment University of Oxford Oxford UK
| | - Diego Lirman
- Rosenstiel School of Marine and Atmospheric Science University of Miami Miami Florida USA
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8
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OUP accepted manuscript. J Mammal 2022. [DOI: 10.1093/jmammal/gyac024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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9
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Oliveira M, Moser CF, Rebelato MM, Camargo PB, Tozetti AM. Trophic ecology of two amphibian species in patches and core forest of Atlantic Forest: A dietary and isotopic approach. AUSTRAL ECOL 2021. [DOI: 10.1111/aec.13107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mateus Oliveira
- Laboratório de Ecologia de Vertebrados Terrestres Universidade do Vale do Rio dos Sinos Av. Unisinos, 950, Bairro Cristo Rei São Leopoldo RS 93022‐750 Brasil
| | | | - Marluci Muller Rebelato
- Departamento de Zoologia Instituto de Biociências Universidade Federal do Rio Grande do Sul Porto Alegre RS Brasil
| | | | - Alexandro Marques Tozetti
- Laboratório de Ecologia de Vertebrados Terrestres Universidade do Vale do Rio dos Sinos Av. Unisinos, 950, Bairro Cristo Rei São Leopoldo RS 93022‐750 Brasil
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10
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Vinterstare J, Ekelund Ugge GMO, Hulthén K, Hegg A, Brönmark C, Nilsson PA, Zellmer UR, Lee M, Pärssinen V, Sha Y, Björnerås C, Zhang H, Gollnisch R, Herzog SD, Hansson LA, Škerlep M, Hu N, Johansson E, Langerhans RB. Predation risk and the evolution of a vertebrate stress response: Parallel evolution of stress reactivity and sexual dimorphism. J Evol Biol 2021; 34:1554-1567. [PMID: 34464014 DOI: 10.1111/jeb.13918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 08/12/2021] [Indexed: 11/29/2022]
Abstract
Predation risk is often invoked to explain variation in stress responses. Yet, the answers to several key questions remain elusive, including the following: (1) how predation risk influences the evolution of stress phenotypes, (2) the relative importance of environmental versus genetic factors in stress reactivity and (3) sexual dimorphism in stress physiology. To address these questions, we explored variation in stress reactivity (ventilation frequency) in a post-Pleistocene radiation of live-bearing fish, where Bahamas mosquitofish (Gambusia hubbsi) inhabit isolated blue holes that differ in predation risk. Individuals of populations coexisting with predators exhibited similar, relatively low stress reactivity as compared to low-predation populations. We suggest that this dampened stress reactivity has evolved to reduce energy expenditure in environments with frequent and intense stressors, such as piscivorous fish. Importantly, the magnitude of stress responses exhibited by fish from high-predation sites in the wild changed very little after two generations of laboratory rearing in the absence of predators. By comparison, low-predation populations exhibited greater among-population variation and larger changes subsequent to laboratory rearing. These low-predation populations appear to have evolved more dampened stress responses in blue holes with lower food availability. Moreover, females showed a lower ventilation frequency, and this sexual dimorphism was stronger in high-predation populations. This may reflect a greater premium placed on energy efficiency in live-bearing females, especially under high-predation risk where females show higher fecundities. Altogether, by demonstrating parallel adaptive divergence in stress reactivity, we highlight how energetic trade-offs may mould the evolution of the vertebrate stress response under varying predation risk and resource availability.
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Affiliation(s)
- Jerker Vinterstare
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Gustaf M O Ekelund Ugge
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden.,School of Bioscience, University of Skövde, Skövde, Sweden
| | - Kaj Hulthén
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Alexander Hegg
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Christer Brönmark
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Per Anders Nilsson
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Ursula Ronja Zellmer
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Marcus Lee
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Varpu Pärssinen
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Yongcui Sha
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Caroline Björnerås
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Huan Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Raphael Gollnisch
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Simon D Herzog
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Lars-Anders Hansson
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Martin Škerlep
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Nan Hu
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Emma Johansson
- Aquatic Ecology Unit, Ecology Building, Department of Biology, Lund University, Lund, Sweden
| | - Randall Brian Langerhans
- Department of Biological Sciences, W.M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC, USA
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11
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Jenkins MR, Cummings JM, Cabe AR, Hulthén K, Peterson MN, Langerhans RB. Natural and anthropogenic sources of habitat variation influence exploration behaviour, stress response, and brain morphology in a coastal fish. J Anim Ecol 2021; 90:2446-2461. [PMID: 34143892 DOI: 10.1111/1365-2656.13557] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 06/16/2021] [Indexed: 11/27/2022]
Abstract
Evolutionary ecology aims to better understand how ecologically important traits respond to environmental heterogeneity. Environments vary both naturally and as a result of human activities, and investigations that simultaneously consider how natural and human-induced environmental variation affect diverse trait types grow increasingly important as human activities drive species endangerment. Here, we examined how habitat fragmentation and structural habitat complexity affect disparate trait types in Bahamas mosquitofish Gambusia hubbsi inhabiting tidal creeks. We tested a priori predictions for how these factors might influence exploratory behaviour, stress reactivity and brain anatomy. We examined approximately 350 adult Bahamas mosquitofish from seven tidal-creek populations across Andros Island, The Bahamas that varied in both human-caused fragmentation (three fragmented and four unfragmented) and natural habitat complexity (e.g. fivefold variation in rock habitat). Populations that had experienced severe human-induced fragmentation, and thus restriction of tidal exchange from the ocean, exhibited greater exploration of a novel environment, stronger physiological stress responses to a mildly stressful event and smaller telencephala (relative to body size). These changes matched adaptive predictions based mostly on (a) reduced chronic predation risk and (b) decreased demands for navigating tidally dynamic habitats. Populations from sites with greater structural habitat complexity showed a higher propensity for exploration and a relatively larger optic tectum and cerebellum. These patterns matched adaptive predictions related to increased demands for navigating complex environments. Our findings demonstrate environmental variation, including recent anthropogenic impacts (<50 years), can significantly affect complex, ecologically important traits. Yet trait-specific patterns may not be easily predicted, as we found strong support for only six of 12 predictions. Our results further highlight the utility of simultaneously quantifying multiple environmental factors-for example had we failed to account for habitat complexity, we would not have detected the effects of fragmentation on exploratory behaviours. These responses, and their ecological consequences, may be complex: rapid and adaptive phenotypic responses to anthropogenic impacts can facilitate persistence in human-altered environments, but may come at a cost of population vulnerability if ecological restoration was to occur without consideration of the altered traits.
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Affiliation(s)
- Matthew R Jenkins
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC, USA
| | - John M Cummings
- Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA
| | - Alex R Cabe
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Kaj Hulthén
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC, USA
| | - M Nils Peterson
- Fisheries, Wildlife, and Conservation Biology Program, North Carolina State University, Raleigh, NC, USA
| | - R Brian Langerhans
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC, USA
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12
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Steube TR, Altenritter ME, Walther BD. Distributive stress: individually variable responses to hypoxia expand trophic niches in fish. Ecology 2021; 102:e03356. [PMID: 33811651 PMCID: PMC8244237 DOI: 10.1002/ecy.3356] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 01/05/2021] [Accepted: 02/05/2021] [Indexed: 01/18/2023]
Abstract
Environmental stress can reshape trophic interactions by excluding predators or rendering prey vulnerable, depending on the relative sensitivity of species to the stressor. Classical models of food web responses to stress predict either complete predator exclusion from stressed areas or complete prey vulnerability if predators are stress tolerant. However, if the consumer response to the stress is individually variable, the result may be a distributive stress model (DSM) whereby predators distribute consumption pressure across a range of prey guilds and their trophic niche is expanded. We test these models in one of the largest hypoxic “Dead Zones” in the world, the northern Gulf of Mexico, by combining geochemical tracers of hypoxia exposure and isotope ratios to assess individual‐level trophic responses. Hypoxia‐exposed fish occupied niche widths that were 14.8% and 400% larger than their normoxic counterparts in two different years, consistent with variable displacement from benthic to pelagic food webs. The degree of isotopic displacement depended on the magnitude of hypoxia exposure. These results are consistent with the DSM and highlight the need to account for individually variable sublethal effects when predicting community responses to environmental stress.
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Affiliation(s)
- Tyler R Steube
- Department of Life Sciences, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, Texas, 78412, USA
| | - Matthew E Altenritter
- Department of Life Sciences, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, Texas, 78412, USA.,Department of Environmental Science & Ecology, The College at Brockport, State University of New York, 350 New Campus Drive, Brockport, New York, 14420, USA
| | - Benjamin D Walther
- Department of Life Sciences, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Corpus Christi, Texas, 78412, USA
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13
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Hulthén K, Hill JS, Jenkins MR, Langerhans RB. Predation and Resource Availability Interact to Drive Life-History Evolution in an Adaptive Radiation of Livebearing Fish. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.619277] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Predation risk and resource availability are two primary factors predicted by theory to drive the evolution of life histories. Yet, disentangling their roles in life-history evolution in the wild is challenging because (1) the two factors often co-vary across environments, and (2) environmental effects on phenotypes can mask patterns of genotypic evolution. Here, we use the model system of the post-Pleistocene radiation of Bahamas mosquitofish (Gambusia hubbsi) inhabiting blue holes to provide a strong test of the roles of predation and resources in life-history evolution, as the two factors do not co-vary in this system and we attempted to minimize environmental effects by raising eight populations under common laboratory conditions. We tested a priori predictions of predation- and resource-driven evolution in five life-history traits. We found that life-history evolution in Bahamas mosquitofish largely reflected complex interactions in the effects of predation and resource availability. High predation risk has driven the evolution of higher fecundity, smaller offspring size, more frequent reproduction, and slower growth rate—but this predation-driven divergence primarily occurred in environments with relatively high resource availability, and the effects of resources on life-history evolution was generally greater within environments having high predation risk. This implies that resource-driven selection on life histories overrides selection from predators when resources are particularly scarce. While several results matched a priori predictions, with the added nuance of interdependence among selective agents, some did not. For instance, only resource levels, not predation risk, explained evolutionary change in male age at maturity, with more rapid sexual maturation in higher-resource environments. We also found faster (not slower) juvenile growth rates within low-resource and low-predation environments, probably caused by selection in these high-competition scenarios favoring greater growth efficiency. Our approach, using common-garden experiments with a natural system of low- and high-predation populations that span a continuum of resource availability, provides a powerful way to deepen our understanding of life-history evolution. Overall, it appears that life-history evolution in this adaptive radiation has resulted from a complex interplay between predation and resources, underscoring the need for increased attention on more sophisticated interactions among selective agents in driving phenotypic diversification.
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Langerhans RB, Goins TR, Stemp KM, Riesch R, Araújo MS, Layman CA. Consuming Costly Prey: Optimal Foraging and the Role of Compensatory Growth. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2020.603387] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Some prey are exceptionally difficult to digest, and yet even non-specialized animals may consume them—why? Durophagy, the consumption of hard-shelled prey, is thought to require special adaptations for crushing or digesting the hard shells to avoid the many potential costs of this prey type. But many animals lacking specializations nevertheless include hard-bodied prey in their diets. We describe several non-mutually exclusive adaptive mechanisms that could explain such a pattern, and point to optimal foraging and compensatory growth as potentially having widespread importance in explaining costly-prey consumption. We first conducted a literature survey to quantify the regularity with which non-specialized teleost fishes consume hard-shelled prey: stomach-content data from 325 teleost fish species spanning 82 families (57,233 stomach samples) demonstrated that non-specialized species comprise ~75% of the total species exhibiting durophagy, commonly consuming hard-shelled prey at low to moderate levels (~10–40% as much as specialists). We then performed a diet survey to assess the frequency of molluscivory across the native latitudinal range of a small livebearing fish, Gambusia holbrooki, lacking durophagy specializations. Molluscivory was regionally widespread, spanning their entire native latitudinal range (>14° latitude). Third, we tested for a higher frequency of molluscivory under conditions of higher intraspecific resource competition in Bahamian mosquitofish (Gambusia spp.). Examining over 5,300 individuals, we found that molluscivory was more common in populations with higher population density, suggesting that food limitation is important in eliciting molluscivory. Finally, we experimentally tested in G. holbrooki whether molluscivory reduces growth rate and whether compensatory growth follows a period of molluscivory. We found that consumption of hard-shelled gastropods results in significantly reduced growth rate, but compensatory growth following prior snail consumption can quickly mitigate growth costs. Our results suggest that the widespread phenomenon of costly-prey consumption may be partially explained by its relative benefits when few alternative prey options exist, combined with compensatory growth that alleviates temporary costs.
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Pärssinen V, Hulthén K, Brönmark C, Björnerås C, Ekelund Ugge G, Gollnisch R, Hansson L, Herzog SD, Hu N, Johansson E, Lee M, Rengefors K, Sha Y, Škerlep M, Vinterstare J, Zhang H, Langerhans RB, Nilsson PA. Variation in predation regime drives sex‐specific differences in mosquitofish foraging behaviour. OIKOS 2021. [DOI: 10.1111/oik.08335] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Kaj Hulthén
- Lund Univ., Aquatic Ecology, Dept of Biology Lund Sweden
| | | | | | - Gustaf Ekelund Ugge
- Lund Univ., Aquatic Ecology, Dept of Biology Lund Sweden
- Univ. of Skövde, School of Bioscience Skövde Sweden
| | | | | | | | - Nan Hu
- Lund Univ., Aquatic Ecology, Dept of Biology Lund Sweden
| | - Emma Johansson
- Lund Univ., Aquatic Ecology, Dept of Biology Lund Sweden
| | - Marcus Lee
- Lund Univ., Aquatic Ecology, Dept of Biology Lund Sweden
| | | | - Yongcui Sha
- Lund Univ., Aquatic Ecology, Dept of Biology Lund Sweden
| | - Martin Škerlep
- Lund Univ., Aquatic Ecology, Dept of Biology Lund Sweden
| | | | - Huan Zhang
- Lund Univ., Aquatic Ecology, Dept of Biology Lund Sweden
- Chinese Academy of Sciences, Inst. of Hydrobiology Wuhan China
| | - R. Brian Langerhans
- North Carolina State Univ., Dept of Biological Sciences and W.M. Keck Center for Behavioral Biology Raleigh USA
| | - P. Anders Nilsson
- Lund Univ., Aquatic Ecology, Dept of Biology Lund Sweden
- Karlstad Univ., River Ecology and Management Research Group RivEM, Dept of Environmental and Life Sciences Karlstad Sweden
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Riesch R, Martin RA, Langerhans RB. Multiple traits and multifarious environments: integrated divergence of morphology and life history. OIKOS 2019. [DOI: 10.1111/oik.06344] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rüdiger Riesch
- School of Biological Sciences, Centre for Ecology, Evolution and Behaviour, Royal Holloway, Univ. of London Egham Surrey TW20 0EX UK
| | - Ryan A. Martin
- Dept of Biology, DeGrace Hall, Case Western Reserve Univ. Cleveland OH USA
| | - R. Brian Langerhans
- Dept of Biological Sciences & W. M. Keck Center for Behavioral Biology, North Carolina State Univ. Raleigh NC USA
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Rhoades OK, Best RJ, Stachowicz JJ. Assessing Feeding Preferences of a Consumer Guild: Partitioning Variation Among versus Within Species. Am Nat 2018; 192:287-300. [PMID: 30125236 DOI: 10.1086/698325] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Interspecific variation in resource use is critical to understanding species diversity, coexistence, and ecosystem functioning. A growing body of research describes analogous intraspecific variation and its potential importance for population dynamics and community outcomes. However, the magnitude of intraspecific variation relative to interspecific variation in key dimensions of consumer-resource interactions remains unknown, hampering our understanding of the importance of this variation for population and community processes. In this study, we examine feeding preference through repeated laboratory choice feeding assays of 444 wild-caught individuals of eight invertebrate grazer species on rocky reefs in northern California. Between-species variation accounted for 25%-33% of the total variation in preference for the preferred resource, while between-individual variation accounted for 4%-5% of total variation. For two of the eight species, between-individual variation was significantly different from zero and on average contributed 14% and 17% of the total diet variation, even after accounting for differences due to size and sex. Therefore, even with clearly distinguishable between-species differences in mean preference, diet variation between and within individuals can contribute to the dietary niche width of species and guilds, which may be overlooked by focusing solely on species' mean resource use patterns.
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Giery ST, Layman CA. Dissolved organic carbon and unimodal variation in sexual signal coloration in mosquitofish: a role for light limitation? Proc Biol Sci 2018; 284:rspb.2017.0163. [PMID: 28381625 DOI: 10.1098/rspb.2017.0163] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/07/2017] [Indexed: 11/12/2022] Open
Abstract
Natural selection plays an important role in the evolution of sexual communication systems. Here, we assess the effect of two well-known selection agents, transmission environment and predation, on interpopulation variation in sexual signals. Our model system is a series of 21 populations of Bahamian mosquitofish subjected to independent variation in optical conditions and predation risk. We show that optically diverse environments, caused by locally variable dissolved organic carbon concentrations, rather than spatial variation in predation, drove divergence in fin coloration (fin redness). We found a unimodal pattern of phenotypic variation along the optical gradient indicating a threshold-type response of visual signals to broad variation in optical conditions. We discuss evolutionary and ecological mechanisms that may drive such a pattern as well as the implications of non-monotonic clines for evolutionary differentiation.
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Affiliation(s)
- Sean T Giery
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695, USA
| | - Craig A Layman
- Department of Applied Ecology, North Carolina State University, Raleigh, NC 27695, USA
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Carvalho-Rocha V, Lopes BC, Neckel-Oliveira S. Interindividual patterns of resource use in three subtropical Atlantic Forest frogs. AUSTRAL ECOL 2017. [DOI: 10.1111/aec.12552] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Vítor Carvalho-Rocha
- Departamento de Ecologia e Zoologia; Universidade Federal de Santa Catarina; Florianópolis Brazil
- Vítor Carvalho-Rocha; 88040-900 Florianópolis - SC; Bairro Córrego Grande; Brazil
| | - Benedito Cortês Lopes
- Departamento de Ecologia e Zoologia; Universidade Federal de Santa Catarina; Florianópolis Brazil
| | - Selvino Neckel-Oliveira
- Departamento de Ecologia e Zoologia; Universidade Federal de Santa Catarina; Florianópolis Brazil
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Calizza E, Costantini ML, Careddu G, Rossi L. Effect of habitat degradation on competition, carrying capacity, and species assemblage stability. Ecol Evol 2017; 7:5784-5796. [PMID: 28811883 PMCID: PMC5552933 DOI: 10.1002/ece3.2977] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 03/03/2017] [Accepted: 03/07/2017] [Indexed: 11/11/2022] Open
Abstract
Changes in species’ trophic niches due to habitat degradation can affect intra‐ and interspecific competition, with implications for biodiversity persistence. Difficulties of measuring species’ interactions in the field limit our comprehension of competition outcomes along disturbance gradients. Thus, information on how habitat degradation can destabilize food webs is scarce, hindering predictions regarding responses of multispecies systems to environmental changes. Seagrass ecosystems are undergoing degradation. We address effects of Posidonia oceanica coverage reduction on the trophic organization of a macroinvertebrate community in the Tyrrhenian Sea (Italy), hypothesizing increased trophic generalism, niche overlap among species and thus competition and decreased community stability due to degraded conditions. Census data, isotopic analysis, and Bayesian mixing models were used to quantify the trophic niches of three abundant invertebrate species, and intra‐ and interspecific isotopic and resource‐use similarity across locations differing in seagrass coverage. This allowed the computation of (1) competition strength, with respect to each other and remaining less abundant species and (2) habitat carrying capacity. To explore effects of the spatial scale on the interactions, we considered both individual locations and the entire study area (“‘meadow scale”). We observed that community stability and habitat carrying capacity decreased as P. oceanica coverage declined, whereas niche width, similarity of resource use and interspecific competition strength between species increased. Competition was stronger, and stability lower, at the meadow scale than at the location scale. Indirect effects of competition and the spatial compartmentalization of species interactions increased stability. Results emphasized the importance of trophic niche modifications for understanding effects of habitat loss on biodiversity persistence. Calculation of competition coefficients based on isotopic distances is a promising tool for describing competitive interactions in real communities, potentially extendible to any subset of ecological niche axes for which specimens’ positions and pairwise distances can be obtained.
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Affiliation(s)
- Edoardo Calizza
- Department of Environmental Biology Sapienza University of Rome Rome Italy.,CoNISMa Rome Italy
| | | | - Giulio Careddu
- Department of Environmental Biology Sapienza University of Rome Rome Italy
| | - Loreto Rossi
- Department of Environmental Biology Sapienza University of Rome Rome Italy.,CoNISMa Rome Italy
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Warry FY, Reich P, Cook PLM, Mac Nally R, Thomson JR, Woodland RJ. Nitrogen loads influence trophic organization of estuarine fish assemblages. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12647] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fiona Y. Warry
- Water Studies Centre School of Chemistry Monash University Clayton VIC 3800 Australia
- Department of Environment, Land, Water and Planning Arthur Rylah Institute for Environmental Research Heidelberg VIC 3084 Australia
| | - Paul Reich
- Water Studies Centre School of Chemistry Monash University Clayton VIC 3800 Australia
- Department of Environment, Land, Water and Planning Arthur Rylah Institute for Environmental Research Heidelberg VIC 3084 Australia
| | - Perran L. M. Cook
- Water Studies Centre School of Chemistry Monash University Clayton VIC 3800 Australia
| | - Ralph Mac Nally
- Institute for Applied Ecology The University of Canberra Bruce ACT 2617 Australia
| | - James R. Thomson
- Department of Environment, Land, Water and Planning Arthur Rylah Institute for Environmental Research Heidelberg VIC 3084 Australia
| | - Ryan J. Woodland
- Water Studies Centre School of Chemistry Monash University Clayton VIC 3800 Australia
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Riesch R, Easter T, Layman CA, Langerhans RB. Rapid human-induced divergence of life-history strategies in Bahamian livebearing fishes (family Poeciliidae). J Anim Ecol 2015; 84:1732-43. [PMID: 26237432 DOI: 10.1111/1365-2656.12425] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 07/14/2015] [Indexed: 01/12/2023]
Abstract
Human-induced rapid environmental change (HIREC) can have dramatic impacts on ecosystems, leading to rapid trait changes in some organisms and extinction in others. Such changes in traits signify that human actions can lead to cases of increased phenotypic diversity and consequently can strongly impact population-, community- and ecosystem-level dynamics. Here, we examine whether the ecological consequences of habitat fragmentation have led to changes in the life histories of three native species of mosquitofish (Gambusia spp.) inhabiting tidal creeks on six different Bahamian islands. We address two important questions: (i) How predictable and parallel are life-history changes in response to HIREC across islands and species, and (ii) what is the relative importance of shared (i.e. parallel) responses to fragmentation, differences between species or islands and species- or island-specific responses to fragmentation? Phenotypic differences between fragmentation regimes were as great or greater than differences between species or islands. While some adult life histories (lean weight and fat content) showed strong, shared responses to fragmentation, offspring-related life histories (embryo fat and fecundity) exhibited idiosyncratic, island-specific responses. While shared responses to fragmentation appeared largely driven by a reduction in piscivorous fish density, increased conspecific density and changes in salinity, we found some evidence that among-population variation in male reproductive investment and embryo fat content may have arisen via variation in conspecific density. Our results suggest that phenotypic responses to HIREC can be complex, with the predictability of response varying across traits. We therefore emphasize the need for more theoretical and empirical work to better understand the predictability of phenotypic responses to human-induced disturbances.
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Affiliation(s)
- Rüdiger Riesch
- School of Biological Sciences, Centre for Ecology, Evolution and Behaviour, Royal Holloway, University of London, Egham, Surrey, TW20 0EX, UK
| | - Tara Easter
- Department of Biological Sciences, W. M. Keck Center for Behavioral Biology, North Carolina State University, 127 David Clark Labs, Raleigh, NC, 27695-7617, USA
- Center for Biological Diversity, PO Box 11374, Portland, OR, 97211-0374, USA
| | - Craig A Layman
- Department of Applied Ecology, North Carolina State University, 127 David Clark Labs, Raleigh, NC, 27695-7617, USA
| | - Randall Brian Langerhans
- Department of Biological Sciences, W. M. Keck Center for Behavioral Biology, North Carolina State University, 127 David Clark Labs, Raleigh, NC, 27695-7617, USA
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Giery ST, Layman CA, Langerhans RB. Anthropogenic ecosystem fragmentation drives shared and unique patterns of sexual signal divergence among three species of Bahamian mosquitofish. Evol Appl 2015; 8:679-91. [PMID: 26240605 PMCID: PMC4516420 DOI: 10.1111/eva.12275] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 04/13/2015] [Indexed: 12/13/2022] Open
Abstract
When confronted with similar environmental challenges, different organisms can exhibit dissimilar phenotypic responses. Therefore, understanding patterns of phenotypic divergence for closely related species requires considering distinct evolutionary histories. Here, we investigated how a common form of human-induced environmental alteration, habitat fragmentation, may drive phenotypic divergence among three closely related species of Bahamian mosquitofish (Gambusia spp.). Focusing on one phenotypic trait (male coloration), having a priori predictions of divergence, we tested whether populations persisting in fragmented habitats differed from those inhabiting unfragmented habitats and examined the consistency of the pattern across species. Species exhibited both shared and unique patterns of phenotypic divergence between the two types of habitats, with shared patterns representing the stronger effect. For all species, populations in fragmented habitats had fewer dorsal-fin spots. In contrast, the magnitude and trajectory of divergence in dorsal-fin color, a sexually selected trait, differed among species. We identified fragmentation-mediated increased turbidity as a possible driver of these trait shifts. These results suggest that even closely related species can exhibit diverse phenotypic responses when encountering similar human-mediated selection regimes. This element of unpredictability complicates forecasting the phenotypic responses of wild organisms faced with anthropogenic change – an important component of biological conservation and ecosystem management.
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Affiliation(s)
- Sean T Giery
- Marine Sciences Program, Department of Biological Sciences, Florida International University North Miami, FL, USA
| | - Craig A Layman
- Marine Sciences Program, Department of Biological Sciences, Florida International University North Miami, FL, USA ; Department of Applied Ecology, David Clark Labs, North Carolina State University Raleigh, NC, 27695, USA
| | - R Brian Langerhans
- Department of Biological Sciences and W.M. Keck Center for Behavioral Biology, North Carolina State University Raleigh, NC, USA
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Giery ST, Layman CA. Interpopulation Variation in a Condition-Dependent Signal: Predation Regime Affects Signal Intensity and Reliability. Am Nat 2015; 186:187-95. [PMID: 26655148 DOI: 10.1086/682068] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In many models of sexual selection, conspicuous ornaments are preferred by mates because they indicate heritable signaler viability. To function as indicators, ornaments must exhibit a proportional relationship between expression and viability. In cases where the evolutionary interests of signaler and receiver diverge, selection favors exploitative exaggeration by low-viability individuals producing unreliable signals. Theory suggests that the evolutionary stability of such communication systems requires costs that prevent low-viability males from expressing disproportionately intense signals. Therefore, given ecological variation in signaling cost, the reliability of signaling systems will vary concomitantly. In this study, we assess the effect of a variable signal cost, predation, on signal intensity and reliability among 16 populations of Bahamas mosquitofish (Gambusia hubbsi) that use colorful dorsal fins in courtship displays. We found that fin coloration was more intense in low-predation sites and could be used to predict body condition. However, this predictive relationship was apparent only in populations subject to predation risk. We demonstrate an important role for ecological signaling cost in communication and show that ecological heterogeneity drives interpopulation variation in both the intensity and the reliability of a sexual signal.
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Affiliation(s)
- Sean T Giery
- Marine Sciences Program, Department of Biological Sciences, Florida International University, 3000 NE 151st Street, North Miami, Florida 33181
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Heinen-Kay JL, Noel HG, Layman CA, Langerhans RB. Human-caused habitat fragmentation can drive rapid divergence of male genitalia. Evol Appl 2014; 7:1252-67. [PMID: 25558285 PMCID: PMC4275096 DOI: 10.1111/eva.12223] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 08/24/2014] [Indexed: 11/29/2022] Open
Abstract
The aim of this study rests on three premises: (i) humans are altering ecosystems worldwide, (ii) environmental variation often influences the strength and nature of sexual selection, and (iii) sexual selection is largely responsible for rapid and divergent evolution of male genitalia. While each of these assertions has strong empirical support, no study has yet investigated their logical conclusion that human impacts on the environment might commonly drive rapid diversification of male genital morphology. We tested whether anthropogenic habitat fragmentation has resulted in rapid changes in the size, allometry, shape, and meristics of male genitalia in three native species of livebearing fishes (genus: Gambusia) inhabiting tidal creeks across six Bahamian islands. We found that genital shape and allometry consistently and repeatedly diverged in fragmented systems across all species and islands. Using a model selection framework, we identified three ecological consequences of fragmentation that apparently underlie observed morphological patterns: decreased predatory fish density, increased conspecific density, and reduced salinity. Our results demonstrate that human modifications to the environment can drive rapid and predictable divergence in male genitalia. Given the ubiquity of anthropogenic impacts on the environment, future research should evaluate the generality of our findings and potential consequences for reproductive isolation.
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Affiliation(s)
- Justa L Heinen-Kay
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University Raleigh, NC, USA
| | - Holly G Noel
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University Raleigh, NC, USA
| | - Craig A Layman
- Department of Applied Ecology, North Carolina State University Raleigh, NC, USA
| | - R Brian Langerhans
- Department of Biological Sciences and W. M. Keck Center for Behavioral Biology, North Carolina State University Raleigh, NC, USA
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