1
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Goldberg JF, Fraser DF, Lamphere BA, Reznick DN. Differential habitat use and recruitment facilitate coexistence in a community with intraguild predation. Ecology 2021; 103:e03558. [PMID: 34622952 DOI: 10.1002/ecy.3558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/30/2021] [Accepted: 07/26/2021] [Indexed: 11/10/2022]
Abstract
Theory predicts that species engaged in intraguild predation (IGP) can only coexist under limited conditions, yet IGP is common in nature. Habitat complexity can promote coexistence by reducing encounter rates, but little information is known about the contribution of differential habitat use. We hypothesized that differential use of alternative habitats promotes coexistence of an intraguild (IG) predator and prey. We evaluated predictions of this hypothesis with an experimental introduction of an IG predator fish into four natural stream communities that previously contained only the IG prey fish. We monitored the development of this IGP over the course of four years to determine how each species used alternative stream habitats. The introduced species preferred pool habitats while the resident species was more evenly distributed across pools and riffles. The density of the resident decreased in the pool habitat preferred by the invader, accompanied by a local increase in the mean of the resident size distribution. Selective predation by the invader on hatchling residents appears to impact the residents' demographic response. The continued recruitment of resident juveniles in riffles, where the introduced species is rare, facilitated the persistence of the resident. This differential use of habitats was not accompanied by a change in the resident's growth rates in either habitat. Our results showed that differential habitat selection and recruitment promoted persistence during an invasion involving IGP, which helps to bridge the gap between theory and observation in explaining coexistence in IGP systems.
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Affiliation(s)
- Joshua F Goldberg
- Department of Evolution, Ecology and Organismal Biology, University of California-Riverside, Riverside, California, 92521, USA
| | - Douglas F Fraser
- Department of Biology, Siena College, Loudonville, New York, 12211, USA
| | - Bradley A Lamphere
- Department of Biological Sciences, University of Mary Washington, 1301 College Avenue, Fredericksburg, Virginia, 22401, USA
| | - David N Reznick
- Department of Evolution, Ecology and Organismal Biology, University of California-Riverside, Riverside, California, 92521, USA
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2
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Anaya-Rojas JM, Bassar RD, Potter T, Blanchette A, Callahan S, Framstead N, Reznick D, Travis J. The evolution of size-dependent competitive interactions promotes species coexistence. J Anim Ecol 2021; 90:2704-2717. [PMID: 34389988 DOI: 10.1111/1365-2656.13577] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 08/04/2021] [Indexed: 12/01/2022]
Abstract
Theory indicates that competing species coexist in a community when intraspecific competition is stronger than interspecific competition. When body size determines the outcome of competitive interactions between individuals, coexistence depends also on how resource use and the ability to compete for these resources change with body size. Testing coexistence theory in size-structured communities, therefore, requires disentangling the effects of size-dependent competitive abilities and niche shifts. Here, we tested the hypothesis that the evolution of species- and size-dependent competitive asymmetries increased the likelihood of coexistence between interacting species. We experimentally estimated the effects of size-dependent competitive interactions on somatic growth rates of two interacting fish species, Trinidadian guppies Poecilia reticulata and killifish Rivulus hartii. We controlled for the effects of size-dependent changes in the niche at two competitive settings representing the early (allopatric) and late (sympatric) evolutionary stages of a killifish-guppy community. We fitted the growth data to a model that incorporates species- and size-dependent competitive asymmetries to test whether changes in the competitive interactions across sizes increased the likelihood of species coexistence from allopatry to sympatry. We found that guppies are competitively superior to killifish but were less so in sympatric populations. The decrease in the effects of interspecific competition on the fitness of killifish and increase in the interspecific effect on guppies' fitness increased the likelihood that sympatric guppies and killifish will coexist. However, while the competitive asymmetries between the species changed consistently between allopatry and sympatry between drainages, the magnitude of the size-dependent competitive asymmetries varied between drainages. These results demonstrate the importance of integrating evolution and trait-based interactions into the research on how species coexist.
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Affiliation(s)
- Jaime M Anaya-Rojas
- Department of Biological Science, Florida State University, Tallahassee, FL, USA.,Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Ronald D Bassar
- Department of Biology, Williams College, Williamstown, MA, USA
| | - Tomos Potter
- Department of Zoology, University of Oxford, Oxford, UK
| | - Allison Blanchette
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Shay Callahan
- University of Illinois at Urbana-Champaign, Urbana-Champaign, IL, USA
| | - Nick Framstead
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - David Reznick
- Department of Evolution, Ecology and Organismal Biology, University of California, Riverside, CA, USA
| | - Joseph Travis
- Department of Biological Science, Florida State University, Tallahassee, FL, USA
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3
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Tuckett QM, Deacon AE, Fraser D, Lyons TJ, Lawson KM, Hill JE. Unstable intraguild predation causes establishment failure of a globally invasive species. Ecology 2021; 102:e03411. [PMID: 34028015 DOI: 10.1002/ecy.3411] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/29/2020] [Accepted: 02/22/2021] [Indexed: 11/06/2022]
Abstract
Biotic resistance is often posited, but rarely known, to be the cause of invasion failure. Competition and predation are the most frequently identified processes that may prevent or limit the establishment of nonnative species. Interactions between nonnative and native species that involve intraguild predation (IGP) are very common in nature, although theory predicts most IGP systems should be unstable and lead to extinction. If this prediction is true, the frequency of invasion failures due to IGP may be underappreciated because of their fleeting nature and, thus, studies of unstable IGP systems are lacking, despite the opportunities they offer for understanding the factors affecting their unstable dynamics. We investigated a failed invasion involving an IGP relationship. In Florida, the guppy (Poecilia reticulata), a worldwide invader, fails to establish in the presence of eastern mosquitofish (Gambusia holbrooki). We tested whether and how resident mosquitofish cause guppy invasion failure using replicated mesocosm and aquarium trials. Both the predator and competitor components of the IGP relationship were strongly asymmetrical, with large impacts on guppies. We identified two effects, direct consumption of neonates and aggressive interference competition, that limited survival and recruitment. The highly unstable nature of this IGP relationship is the primary cause of the failure of the guppy to establish in Florida. Our study shows that the transient nature of an ephemeral IGP relationship can yield important insights into the underlying causes of invasion failure, including the role of strong biotic resistance.
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Affiliation(s)
- Quenton M Tuckett
- Tropical Aquaculture Laboratory, Program in Fisheries and Aquatic Sciences, School of Forest Resources and Conservation, University of Florida, Ruskin, Florida, 33570, USA
| | - Amy E Deacon
- Department of Life Sciences, The University of the West Indies, St Augustine, Trinidad and Tobago
| | - Douglas Fraser
- Department of Biology, Siena College, Loudonville, New York, 12211, USA
| | - Timothy J Lyons
- Tropical Aquaculture Laboratory, Program in Fisheries and Aquatic Sciences, School of Forest Resources and Conservation, University of Florida, Ruskin, Florida, 33570, USA
| | - Katelyn M Lawson
- Department of Biological Sciences, Auburn University, Auburn, Alabama, 36849, USA
| | - Jeffrey E Hill
- Tropical Aquaculture Laboratory, Program in Fisheries and Aquatic Sciences, School of Forest Resources and Conservation, University of Florida, Ruskin, Florida, 33570, USA
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4
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Novel parasite invasion leads to rapid demographic compensation and recovery in an experimental population of guppies. Proc Natl Acad Sci U S A 2020; 117:22580-22589. [PMID: 32848066 DOI: 10.1073/pnas.2006227117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The global movement of pathogens is altering populations and communities through a variety of direct and indirect ecological pathways. The direct effect of a pathogen on a host is reduced survival, which can lead to decreased population densities. However, theory also suggests that increased mortality can lead to no change or even increases in the density of the host. This paradoxical result can occur in a regulated population when the pathogen's negative effect on survival is countered by increased reproduction at the lower density. Here, we analyze data from a long-term capture-mark-recapture experiment of Trinidadian guppies (Poecilia reticulata) that were recently infected with a nematode parasite (Camallanus cotti). By comparing the newly infected population with a control population that was not infected, we show that decreases in the density of the infected guppy population were transient. The guppy population compensated for the decreased survival by a density-dependent increase in recruitment of new individuals into the population, without any change in the underlying recruitment function. Increased recruitment was related to an increase in the somatic growth of uninfected fish. Twenty months into the new invasion, the population had fully recovered to preinvasion densities even though the prevalence of infection of fish in the population remained high (72%). These results show that density-mediated indirect effects of novel parasites can be positive, not negative, which makes it difficult to extrapolate to how pathogens will affect species interactions in communities. We discuss possible hypotheses for the rapid recovery.
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5
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Abstract
Natural history is the careful observation of nature, wherever nature is. Ultimately, it is what ecological, evolutionary, and behavioral science are supposed to explain. It is difficult to use natural history alone to test hypotheses in these fields because of the complex paths between process and pattern. Few patterns are predicted by one and only one hypothesis, so experiments are almost always necessary. However, the robustness of experimental results depends on how well experimental conditions reflect the integration of natural history. Natural history also plays a vital role in how well we can apply Krogh's principle to our work. Krogh's principle is that scientists begin with an important hypothesis and find a system (organism, habitat, species interaction) with which to test it. However, natural history is essential for knowing whether the question applies to the system or whether we are forcing the question on the system. There is value in beginning one's research not by identifying an interesting question and searching for the right system but by identifying an interesting system in which to ask the right question. This approach carries the danger of parochialism, which can be avoided only by having a command of theory as well as natural history. A command of both areas allows nature to tell us which question to ask instead of demanding that nature answer the question we find most interesting.
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6
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Dunlap KD, Corbo JH, Vergara MM, Beston SM, Walsh MR. Predation drives the evolution of brain cell proliferation and brain allometry in male Trinidadian killifish, Rivulus hartii. Proc Biol Sci 2019; 286:20191485. [PMID: 31822257 PMCID: PMC6939915 DOI: 10.1098/rspb.2019.1485] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 11/14/2019] [Indexed: 02/03/2023] Open
Abstract
The external environment influences brain cell proliferation, and this might contribute to brain plasticity underlying adaptive behavioural changes. Additionally, internal genetic factors influence the brain cell proliferation rate. However, to date, researchers have not examined the importance of environmental versus genetic factors in causing natural variation in brain cell proliferation. Here, we examine brain cell proliferation and brain growth trajectories in free-living populations of Trinidadian killifish, Rivulus hartii, exposed to contrasting predation environments. Compared to populations without predators, populations in high predation (HP) environments exhibited higher rates of brain cell proliferation and a steeper brain growth trajectory (relative to body size). To test whether these differences in the wild persist in a common garden environment, we reared first-generation fish originating from both predation environments in uniform laboratory conditions. Just as in the wild, brain cell proliferation and brain growth in the common garden were greater in HP populations than in no predation populations. The differences in cell proliferation observed across the brain in both the field and common garden studies indicate that the differences are probably genetically based and are mediated by evolutionary shifts in overall brain growth and life-history traits.
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Affiliation(s)
- Kent D. Dunlap
- Department of Biology, Trinity College, Hartford, CT 06106, USA
| | - Joshua H. Corbo
- Department of Biology, Trinity College, Hartford, CT 06106, USA
| | | | - Shannon M. Beston
- Department of Biology, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Matthew R. Walsh
- Department of Biology, University of Texas at Arlington, Arlington, TX 76019, USA
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7
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Reznick DN, Travis J. Experimental Studies of Evolution and Eco-Evo Dynamics in Guppies (Poecilia reticulata). ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2019. [DOI: 10.1146/annurev-ecolsys-110218-024926] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Guppies in Trinidad range across aquatic environments with fish communities that vary in risk of predation. These communities are often discrete, separated by waterfalls, with high-predation communities downstream and low-predation communities upstream. This gradient is repeated in many rivers; in each one, we see the same divergence between guppy populations in life history, behavior, morphology, and physiology. We have shown that the agent of selection on the life history, behavior, and physiology in low-predation communities is high population density and the cascade of ecological effects that stems from it. In effect, guppy populations modify their ecosystem and, in so doing, impose selection on themselves and shape their own evolution, which further changes the ecosystem. Evolution unfolds rapidly in this system, which has enabled us to study the dynamics of the process, not just its end points. Those studies enable us to answer some very general questions in ecology and evolutionary biology.
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Affiliation(s)
- David N. Reznick
- Department of Evolution, Ecology and Organismal Biology, University of California, Riverside, California 92521, USA
| | - Joseph Travis
- Department of Biological Sciences, Florida State University, Tallahassee, Florida 32306, USA
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8
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Reznick DN, Bassar RD, Handelsman CA, Ghalambor CK, Arendt J, Coulson T, Potter T, Ruell EW, Torres-Dowdall J, Bentzen P, Travis J. Eco-Evolutionary Feedbacks Predict the Time Course of Rapid Life-History Evolution. Am Nat 2019; 194:671-692. [DOI: 10.1086/705380] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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9
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Simon TN, Binderup AJ, Flecker AS, Gilliam JF, Marshall MC, Thomas SA, Travis J, Reznick DN, Pringle CM. Landscape patterns in top-down control of decomposition: omnivory disrupts a tropical detrital-based trophic cascade. Ecology 2019; 100:e02723. [PMID: 30973962 DOI: 10.1002/ecy.2723] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 02/11/2019] [Accepted: 03/12/2019] [Indexed: 11/05/2022]
Abstract
Detrital-based trophic cascades are often considered weak or absent in tropical stream ecosystems because of the prevalence of omnivorous macroconsumers and the dearth of leaf-shredding insects. In this study, we isolate top-down effects of three macroconsumer species on detrital processing in headwater streams draining Trinidad's northern mountains. We separated effects of different macroconsumers by experimentally manipulating their temporal access to isolated benthic habitat over the diel cycle. We found no evidence that omnivorous macroconsumers, including a freshwater crab (Eudaniela garmani) and guppy (Poecilia reticulata), increased leaf decomposition via consumption. By contrast, above a waterfall excluding guppies, the insectivorous killifish, Anablepsoides hartii, reduced the biomass of the leaf-shredding insect Phylloicus hansoni 4-fold, which consequently reduced leaf decomposition rates 1.6-fold. This detrital cascade did not occur below the barrier waterfall, where omnivorous guppies join the assemblage and reduce killifish densities; here killifish had no significant effects on Phylloicus or decomposition rates. These patterns of detrital processing were also observed in upstream-downstream comparisons in a landscape study across paired reaches of six streams. Above waterfalls, where killifish were present, but guppies absent, leaf decomposition rates and Phylloicus biomass were 2.5- and ~35-fold lower, respectively, compared to measurements below waterfalls. Moreover, the strength of top-down control by killifish is reflected by the 20- and 5-fold reductions in variability (±SE) surrounding mean Phylloicus biomass and leaf decomposition rates in upstream relative to downstream reaches where no top-down control was detected. Findings show a clear, detrital-based trophic cascade among killifish, a leaf-shredding insect, and leaf decomposition rates. Results also show how omnivorous guppies disrupt this cascade by depressing killifish densities, thereby releasing invertebrate shredders from predation, and significantly increasing decomposition rates. Moreover, this combination of direct and indirect trophic interactions drives patterns in decomposition rates in stream networks at a landscape scale, resulting in significantly lower rates of decomposition above vs. below barrier waterfalls. Our findings reveal that omnivory can result in significant indirect effects on a key ecosystem process, illustrating the importance of these hidden trophic pathways in detrital-based systems and suggesting that resource control in tropical systems may be even more complex than previously envisioned.
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Affiliation(s)
- Troy N Simon
- Odum School of Ecology, University of Georgia, Athens, Georgia, 30602, USA.,Warnell School of Forestry and Natural Resources, University of Georgia, Athens, Georgia, 30602, USA
| | - Andrew J Binderup
- Odum School of Ecology, University of Georgia, Athens, Georgia, 30602, USA
| | - Alex S Flecker
- Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, 14853, USA
| | - James F Gilliam
- Department of Biology, North Carolina State University, Raleigh, North Carolina, 27695, USA
| | - Michael C Marshall
- Odum School of Ecology, University of Georgia, Athens, Georgia, 30602, USA
| | - Steven A Thomas
- School of Natural Resources, University of Nebraska-Lincoln, Lincoln, Nebraska, 68583, USA
| | - Joseph Travis
- Department of Biological Science, Florida State University, Tallahassee, Florida, 32306, USA
| | - David N Reznick
- Department of Biology, University of California-Riverside, Riverside, California, 92521, USA
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10
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Beston SM, Walsh MR. Natural selection favours a larger eye in response to increased competition in natural populations of a vertebrate. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13334] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shannon M. Beston
- Department of Biology University of Texas at Arlington Arlington Texas
| | - Matthew R. Walsh
- Department of Biology University of Texas at Arlington Arlington Texas
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11
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Abstract
Headwaters, the sources of all stream networks, provide habitats that are unique from other freshwater environments and are used by a specialised subset of aquatic species. The features of headwaters that provide special habitats include predator-free or competitor-free spaces; specific resources (particularly detrital based); and moderate variations in flows, temperature and discharge. Headwaters provide key habitats for all or some life stages for a large number of species across just about all freshwater phyla and divisions. Some features of headwaters, including isolation and small population sizes, have allowed for the evolutionary radiation of many groups of organisms within and beyond those habitats. As small and easily engineered physical spaces, headwaters are easily degraded by streambank development, ditching and even burial. Headwater streams are among the most sensitive of freshwater ecosystems due to their intimate linkage with their catchments and how easily they are impacted. As a unique ecosystem with many specialist species, headwater streams deserve better stewardship.
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12
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Deacon AE, Jones FAM, Magurran AE. Gradients in predation risk in a tropical river system. Curr Zool 2018; 64:213-221. [PMID: 30402062 PMCID: PMC5905555 DOI: 10.1093/cz/zoy004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 01/05/2018] [Indexed: 01/30/2023] Open
Abstract
The importance of predation risk as a key driver of evolutionary change is exemplified by the Northern Range in Trinidad, where research on guppies living in multiple parallel streams has provided invaluable insights into the process of evolution by natural selection. Although Trinidadian guppies are now a textbook example of evolution in action, studies have generally categorized predation as a dichotomous variable, representing high or low risk. Yet, ecologists appreciate that community structure and the attendant predation risk vary substantially over space and time. Here, we use data from a longitudinal study of fish assemblages at 16 different sites in the Northern Range to quantify temporal and spatial variation in predation risk. Specifically we ask: 1) Is there evidence for a gradient in predation risk? 2) Does the ranking of sites (by risk) change with the definition of the predator community (in terms of species composition and abundance currency), and 3) Are site rankings consistent over time? We find compelling evidence that sites lie along a continuum of risk. However, site rankings along this gradient depend on how predation is quantified in terms of the species considered to be predators and the abundance currency is used. Nonetheless, for a given categorization and currency, rankings are relatively consistent over time. Our study suggests that consideration of predation gradients will lead to a more nuanced understanding of the role of predation risk in behavioral and evolutionary ecology. It also emphasizes the need to justify and report the definition of predation risk being used.
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Affiliation(s)
- Amy E Deacon
- Department of Life Sciences, The University of the West Indies, St Augustine, Trinidad and Tobago
- School of Biology, University of St Andrews, Fife, KY16 9TH Scotland, UK
| | - Faith A M Jones
- School of Biology, University of St Andrews, Fife, KY16 9TH Scotland, UK
| | - Anne E Magurran
- School of Biology, University of St Andrews, Fife, KY16 9TH Scotland, UK
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13
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Pérez-Jvostov F, Hendry AP, Fussmann GF, Scott ME. Experimental Assessment in Nature of the Ecological Effects of a Specialist Parasite. COPEIA 2017. [DOI: 10.1643/ce-16-525] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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14
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Beston SM, Wostl E, Walsh MR. The evolution of vertebrate eye size across an environmental gradient: phenotype does not predict genotype in a Trinidadian killifish. Evolution 2017; 71:2037-2049. [PMID: 28574174 DOI: 10.1111/evo.13283] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 05/05/2017] [Accepted: 05/09/2017] [Indexed: 11/28/2022]
Abstract
Vertebrates exhibit substantial variation in eye size. Eye size correlates positively with visual capacity and behaviors that enhance fitness, such as predator avoidance. This foreshadows a connection between predation and eye size evolution. Yet, the conditions that favor evolutionary shifts in eye size, besides the well-known role for light availability, are unclear. We tested the influence of predation on the evolution of eye size in Trinidadian killifish, Rivulus hartii. Rivulus are located across a series of communities where they coexist with visually oriented piscivores ("high predation" sites), and no predators ("Rivulus-only" sites). Wild-caught Rivulus from high predation sites generally exhibited a smaller relative eye size than communities that lack predators. Yet, such differences were inconsistent across rivers. Second-generation common garden reared fish revealed repeatable decreases in eye size in Rivulus from high predation sites. We performed additional experiments that tested the importance of light and resources on eye size evolution. Sites that differ in light or resource availability did not differ in eye size. Our results argue that differences in predator-induced mortality underlie genetically-based shifts in vertebrate eye size. We discuss the drivers of eye size evolution in light of the nonparallel trends between the phenotypic and common garden results.
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Affiliation(s)
- Shannon M Beston
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
| | - Elijah Wostl
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
| | - Matthew R Walsh
- Department of Biology, University of Texas at Arlington, Arlington, Texas, 76019
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15
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Warbanski ML, Marques P, Frauendorf TC, Phillip DAT, El-Sabaawi RW. Implications of guppy ( Poecilia reticulata) life-history phenotype for mosquito control. Ecol Evol 2017; 7:3324-3334. [PMID: 28515869 PMCID: PMC5433973 DOI: 10.1002/ece3.2666] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 10/28/2016] [Accepted: 11/04/2016] [Indexed: 12/04/2022] Open
Abstract
Guppies (Poecilia reticulata) are frequently introduced to both natural and artificial water bodies as a mosquito control. Laboratory studies have demonstrated that guppies can consume large numbers of larval mosquitoes. Our study investigates how intraspecific variability in guppy phenotype affects their importance as a mosquito biocontrol and how habitat conditions (natural ponds vs. water storage containers) may influence insect biomass and guppy feeding. Using a blocked experimental design, we established stream‐side mesocosm ponds with half receiving gravel substrate to simulate pond‐bottom habitat. To provide realistic diet choices and insect abundances, we allowed the mesocosms to colonize naturally with aquatic insect larvae for 1 month before introducing guppies. We tested two distinct guppy phenotypes (from high‐ and low‐predation streams) alongside fish‐free controls. After 1 month, we measured insect biomass in the mesocosms and examined guppy gut contents to document direct predation. While overall insect biomass was not significantly different across the three fish treatments, we observed a significant reduction in mosquito biomass in fish treatments compared to fish‐free controls, as well as intraspecific differences in feeding. Overall insect biomass was significantly higher in mesocosms without gravel, while habitat condition had no effect on mosquito biomass. As guppy phenotype responds to changes in their environments, it is an important consideration for biocontrol policy to anticipate potential ecosystem effects. We close by relating our findings to other studies and by discussing the implications and potential risks of using guppies to control mosquitoes.
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Affiliation(s)
| | - Piata Marques
- Biology Department University of Victoria Victoria BC Canada
| | | | - Dawn A T Phillip
- Department of Life Sciences The University of the West Indies St Augustine Trinidad and Tobago
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16
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Beston SM, Broyles W, Walsh MR. Increased juvenile predation is not associated with evolved differences in adult brain size in Trinidadian killifish ( Rivulus hartii). Ecol Evol 2017; 7:884-894. [PMID: 28168025 PMCID: PMC5288286 DOI: 10.1002/ece3.2668] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/02/2016] [Accepted: 11/05/2016] [Indexed: 11/12/2022] Open
Abstract
Vertebrates exhibit extensive variation in brain size. The long-standing assumption is that this variation is driven by ecologically mediated selection. Recent work has shown that an increase in predator-induced mortality is associated with evolved increases and decreases in brain size. Thus, the manner in which predators induce shifts in brain size remains unclear. Increased predation early in life is a key driver of many adult traits, including life-history and behavioral traits. Such results foreshadow a connection between age-specific mortality and selection on adult brain size. Trinidadian killifish, Rivulus hartii, are found in sites with and without guppies, Poecilia reticulata. The densities of Rivulus drop dramatically in sites with guppies because guppies prey upon juvenile Rivulus. Previous work has shown that guppy predation is associated with the evolution of adult life-history traits in Rivulus. In this study, we compared second-generation laboratory-born Rivulus from sites with and without guppies for differences in brain size and associated trade-offs between brain size and other components of fitness. Despite the large amount of existing research on the importance of early-life events on the evolution of adult traits, and the role of predation on both behavior and brain size, we did not find an association between the presence of guppies and evolutionary shifts in Rivulus brain size. Such results argue that increased rates of juvenile mortality may not alter selection on adult brain size.
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Affiliation(s)
| | - Whitnee Broyles
- Department of BiologyUniversity of Texas at ArlingtonArlingtonTXUSA
| | - Matthew R. Walsh
- Department of BiologyUniversity of Texas at ArlingtonArlingtonTXUSA
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17
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Collins SM, Thomas SA, Heatherly T, MacNeill KL, Leduc AOHC, López-Sepulcre A, Lamphere BA, El-Sabaawi RW, Reznick DN, Pringle CM, Flecker AS. Fish introductions and light modulate food web fluxes in tropical streams: a whole-ecosystem experimental approach. Ecology 2016; 97:3154-3166. [PMID: 27870030 DOI: 10.1002/ecy.1530] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 05/31/2016] [Accepted: 07/08/2016] [Indexed: 12/26/2022]
Abstract
Decades of ecological study have demonstrated the importance of top-down and bottom-up controls on food webs, yet few studies within this context have quantified the magnitude of energy and material fluxes at the whole-ecosystem scale. We examined top-down and bottom-up effects on food web fluxes using a field experiment that manipulated the presence of a consumer, the Trinidadian guppy Poecilia reticulata, and the production of basal resources by thinning the riparian forest canopy to increase incident light. To gauge the effects of these reach-scale manipulations on food web fluxes, we used a nitrogen (15 N) stable isotope tracer to compare basal resource treatments (thinned canopy vs. control) and consumer treatments (guppy introduction vs. control). The thinned canopy stream had higher primary production than the natural canopy control, leading to increased N fluxes to invertebrates that feed on benthic biofilms (grazers), fine benthic organic matter (collector-gatherers), and organic particles suspended in the water column (filter feeders). Stream reaches with guppies also had higher primary productivity and higher N fluxes to grazers and filter feeders. In contrast, N fluxes to collector-gatherers were reduced in guppy introduction reaches relative to upstream controls. N fluxes to leaf-shredding invertebrates, predatory invertebrates, and the other fish species present (Hart's killifish, Anablepsoides hartii) did not differ across light or guppy treatments, suggesting that effects on detritus-based linkages and upper trophic levels were not as strong. Effect sizes of guppy and canopy treatments on N flux rates were similar for most taxa, though guppy effects were the strongest for filter feeding invertebrates while canopy effects were the strongest for collector-gatherer invertebrates. Combined, these results extend previous knowledge about top-down and bottom-up controls on ecosystems by providing experimental, reach-scale evidence that both pathways can act simultaneously and have equally strong influence on nutrient fluxes from inorganic pools through primary consumers.
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Affiliation(s)
- Sarah M Collins
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, 14853, USA.,Department of Fisheries and Wildlife, Michigan State University, 13 Natural Resources, East Lansing, Michigan, 48824, USA
| | - Steven A Thomas
- School of Natural Resources, University of Nebraska-Lincoln, Hardin Hall Room 403, Lincoln, Nebraska, 68583, USA
| | - Thomas Heatherly
- School of Natural Resources, University of Nebraska-Lincoln, Hardin Hall Room 403, Lincoln, Nebraska, 68583, USA.,Department of Ecology, State University of Rio de Janeiro, 524 Rua São Francisco Xavier, Rio de Janeiro, Rio de Janeiro, 20550-013, Brazil
| | - Keeley L MacNeill
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, 14853, USA
| | - Antoine O H C Leduc
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, 14853, USA.,Institute of Biology, Federal University of Bahia, Ondina Campus, Rua Barão de Geremoabo, 147, Salvador, Bahia, 40170-290, Brazil
| | - Andrés López-Sepulcre
- CNRS UMR 7618, Institute of Ecology and Environmental Sciences Paris (iEES), Université Pierre et Marie Curie, 7 Quai Saint Bernard, Paris, 75252, France.,Deptartment of Biological and Environmental Sciences, University of Jyväskylä, PO Box 35, Jyväskylä, 40014, Finland
| | - Bradley A Lamphere
- Biology Department, College of William and Mary, Williamsburg, Virginia, 23187, USA
| | - Rana W El-Sabaawi
- Department of Biology, University of Victoria, PO Box 1700 STN CSC, Victoria, British Columbia, V8W 2Y2, Canada
| | - David N Reznick
- Department of Biology, University of California Riverside, 209 University Laboratory Building, Riverside, California, 92521, USA
| | | | - Alexander S Flecker
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, 14853, USA
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Bassar RD, Simon T, Roberts W, Travis J, Reznick DN. The evolution of coexistence: Reciprocal adaptation promotes the assembly of a simple community. Evolution 2016; 71:373-385. [DOI: 10.1111/evo.13086] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/26/2016] [Accepted: 09/30/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Ronald D. Bassar
- Department of Zoology University of Oxford Oxford United Kingdom
| | - Troy Simon
- Odum School of Ecology University of Georgia Athens Georgia
- Warnell School of Forestry and Natural Resources University of Georgia Athens Georgia
| | - William Roberts
- Department of Biology University of California Riverside California
| | - Joseph Travis
- Department of Biological Science Florida State University Tallahassee Florida
| | - David N. Reznick
- Department of Biology University of California Riverside California
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Pérez-Jvostov F, Hendry AP, Fussmann GF, Scott ME. An experimental test of antagonistic effects of competition and parasitism on host performance in semi-natural mesocosms. OIKOS 2015. [DOI: 10.1111/oik.02499] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Felipe Pérez-Jvostov
- Inst. of Parasitology and Centre for Host-Parasite Interactions, McGill University; 21111 Lakeshore Road Ste. Anne de Bellevue QC H9X 3V9 Canada
| | - Andrew P. Hendry
- Redpath Museum, McGill University; 859 Sherbrooke Street West Montreal QC H3A 2K6 Canada
| | - Gregor F. Fussmann
- Dept of Biology; McGill University; 1205 Docteur Penfield Montreal QC H3A 1B1 Canada
| | - Marilyn E. Scott
- Inst. of Parasitology and Centre for Host-Parasite Interactions, McGill University; 21111 Lakeshore Road Ste. Anne de Bellevue QC H9X 3V9 Canada
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20
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Reznick D. Hard and Soft Selection Revisited: How Evolution by Natural Selection Works in the Real World. J Hered 2015; 107:3-14. [PMID: 26424874 DOI: 10.1093/jhered/esv076] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 08/25/2015] [Indexed: 11/13/2022] Open
Abstract
The modern synthesis of evolutionary biology unified Darwin's natural selection with Mendelian genetics, but at the same time it created the dilemma of genetic load. Lewontin and Hubby's (1966) and Harris's (1966) characterization of genetic variation in natural populations increased the apparent burden of this load. Neutrality or near neutrality of genetic variation was one mechanism proposed for the revealed excessive genetic variation. Bruce Wallace coined the term "soft selection" to describe an alternative way for natural selection to operate that was consistent with observed variation. He envisioned nature as presenting ecological vacancies that could be filled by diverse genotypes. Survival and successful reproduction was a combined function of population density, genotype, and genotype frequencies, rather than a fixed value of the relative fitness of each genotype. My goal in this review is to explore the importance of soft selection in the real world. My motive and that of my colleagues as described here is not to explain what maintains genetic variation in natural populations, but rather to understand the factors that shape how organisms adapt to natural environments. We characterize how feedbacks between ecology and evolution shape both evolution and ecology. These feedbacks are mediated by density- and frequency-dependent selection, the mechanisms that underlie soft selection. Here, I report on our progress in characterizing these types of selection with a combination of a consideration of the published literature and the results from my collaborators' and my research on natural populations of guppies.
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Affiliation(s)
- David Reznick
- From the Department of Biology, University of California, Riverside, CA 92521, USA
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21
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Elvidge CK, Brown GE. Size-based differences determine the contextual value of risky information in heterospecific information use. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2015.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Travis J, Reznick D, Bassar RD, López-Sepulcre A, Ferriere R, Coulson T. Do Eco-Evo Feedbacks Help Us Understand Nature? Answers From Studies of the Trinidadian Guppy. ADV ECOL RES 2014. [DOI: 10.1016/b978-0-12-801374-8.00001-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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