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9. Population variation in the trophic niche of the Trinidadian guppy from different predation regimes.

Author

Zandonà, Eugenia, Dalton, Christopher M, El-Sabaawi, Rana W, Howard, Jason L, Marshall, Michael C, Kilham, Susan S, Reznick, David N, Travis, Joseph, Kohler, Tyler J, Flecker, Alexander S, Thomas, Steven A, and Pringle, Catherine M

Subjects
Animals, Poecilia, Diet, Predatory Behavior, Ecosystem, Seasons, Rivers, Population Dynamics, Adaptation, Physiological, Geography, West Indies, Female, Male, Biological Evolution, Adaptation, Physiological
Abstract

Population variation in trophic niche is widespread among organisms and is of increasing interest given its role in both speciation and adaptation to changing environments. Trinidadian guppies (Poecilia reticulata) inhabiting stream reaches with different predation regimes have rapidly evolved divergent life history traits. Here, we investigated the effects of both predation and resource availability on guppy trophic niches by evaluating their gut contents, resource standing stocks, and δ15N and δ13C stable isotopes across five streams during the wet season. We found that guppies from low predation (LP) sites had a consistently higher trophic position and proportion of invertebrates in their guts and assimilate less epilithon than guppies from high predation (HP) sites. Higher trophic position was also associated with lower benthic invertebrate availability. Our results suggest that LP guppies could be more efficient invertebrate consumers, possibly as an evolutionary response to greater intraspecific competition for higher quality food. This may be intensified by seasonality, as wet season conditions can alter resource availability, feeding rates, and the intensity of intraspecific competition. Understanding how guppy diets vary among communities is critical to elucidating the role of niche shifts in mediating the link between environmental change and the evolution of life histories.

Published
2017

14. Narrow thermal tolerance and low dispersal drive higher speciation in tropical mountains

Author

Polato, Nicholas R., Gill, Brian A., Shah, Alisha A., Gray, Miranda M., Casner, Kayce L., Barthelet, Antoine, Messer, Philipp W., Simmons, Mark P., Guayasamin, Juan M., Encalada, Andrea C., Kondratieff, Boris C., Flecker, Alexander S., Thomas, Steven A., Ghalambor, Cameron K., Poff, N. LeRoy, Funk, W. Chris, and Zamudio, Kelly R.

Published
2018

15. Impacts of detritivore diversity loss on instream decomposition are greatest in the tropics

Author

Boyero, Luz, López-Rojo, Naiara, Tonin, Alan M., Pérez, Javier, Correa-Araneda, Francisco, Pearson, Richard G., Bosch, Jaime, Albariño, Ricardo J., Anbalagan, Sankarappan, Barmuta, Leon A., Basaguren, Ana, Burdon, Francis J., Caliman, Adriano, Callisto, Marcos, Calor, Adolfo R., Campbell, Ian C., Cardinale, Bradley J., Jesús Casas, J., Chará-Serna, Ana M., Chauvet, Eric, Ciapała, Szymon, Colón-Gaud, Checo, Cornejo, Aydeé, Davis, Aaron M., Degebrodt, Monika, Dias, Emerson S., Díaz, María E., Douglas, Michael M., Encalada, Andrea C., Figueroa, Ricardo, Flecker, Alexander S., Fleituch, Tadeusz, García, Erica A., García, Gabriela, García, Pavel E., Gessner, Mark O., Gómez, Jesús E., Gómez, Sergio, Gonçalves, Jr, Jose F., Graça, Manuel A. S., Gwinn, Daniel C., Hall, Jr, Robert O., Hamada, Neusa, Hui, Cang, Imazawa, Daichi, Iwata, Tomoya, Kariuki, Samuel K., Landeira-Dabarca, Andrea, Laymon, Kelsey, Leal, María, Marchant, Richard, Martins, Renato T., Masese, Frank O., Maul, Megan, McKie, Brendan G., Medeiros, Adriana O., Erimba, Charles M. M’, Middleton, Jen A., Monroy, Silvia, Muotka, Timo, Negishi, Junjiro N., Ramírez, Alonso, Richardson, John S., Rincón, José, Rubio-Ríos, Juan, dos Santos, Gisele M., Sarremejane, Romain, Sheldon, Fran, Sitati, Augustine, Tenkiano, Nathalie S. D., Tiegs, Scott D., Tolod, Janine R., Venarsky, Michael, Watson, Anne, and Yule, Catherine M.

Published
2021
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16. Boosting Efficiency for Computing the Pareto Frontier on Tree Structured Networks

Author

Gomes-Selman, Jonathan M., Shi, Qinru, Xue, Yexiang, García-Villacorta, Roosevelt, Flecker, Alexander S., Gomes, Carla P., Hutchison, David, Series Editor, Kanade, Takeo, Series Editor, Kittler, Josef, Series Editor, Kleinberg, Jon M., Series Editor, Mattern, Friedemann, Series Editor, Mitchell, John C., Series Editor, Naor, Moni, Series Editor, Pandu Rangan, C., Series Editor, Steffen, Bernhard, Series Editor, Terzopoulos, Demetri, Series Editor, Tygar, Doug, Series Editor, Weikum, Gerhard, Series Editor, and van Hoeve, Willem-Jan, editor

Published
2018
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23. Drivers of nitrogen transfer in stream food webs across continents

Author

Norman, Beth C., Whiles, Matt R., Collins, Sarah M., Flecker, Alexander S., Hamilton, Steve K., Johnson, Sherri L., Rosi, Emma J., Ashkenas, Linda R., Bowden, William B., Crenshaw, Chelsea L., Crowl, Todd, Dodds, Walter K., Hall, Robert O., El-Sabaawi, Rana, Griffiths, Natalie A., Marti, Eugènia, McDowell, William H., Peterson, Scot D., Rantala, Heidi M., Riis, Tenna, Simon, Kevin S., Tank, Jennifer L., Thomas, Steven A., von Schiller, Daniel, and Webster, Jackson R.

Published
2017

30. Effects of consumer interactions on benthic resources and ecosystem processes in a neotropical stream.

Author

Marshall, Michael C, Binderup, Andrew J, Zandonà, Eugenia, Goutte, Sandra, Bassar, Ronald D, El-Sabaawi, Rana W, Thomas, Steven A, Flecker, Alexander S, Kilham, Susan S, Reznick, David N, and Pringle, Cathy M

Subjects
Animals, Fundulidae, Poecilia, Brachyura, Plants, Plant Leaves, Chlorophyll, Predatory Behavior, Ecosystem, Biomass, Food Chain, Rivers, Phenotype, Trinidad and Tobago, Biological Evolution, Chlorophyll A, General Science & Technology
Abstract

The effect of consumers on their resources has been demonstrated in many systems but is often confounded by trophic interactions with other consumers. Consumers may also have behavioral and life history adaptations to each other and to co-occurring predators that may additionally modulate their particular roles in ecosystems. We experimentally excluded large consumers from tile periphyton, leaves and natural benthic substrata using submerged electrified frames in three stream reaches with overlapping consumer assemblages in Trinidad, West Indies. Concurrently, we assessed visits to (non-electrified) control frames by the three most common large consumers-primarily insectivorous killifish (Rivulus hartii), omnivorous guppies (Poecilia reticulata) and omnivorous crabs (Eudaniela garmani). Consumers caused the greatest decrease in final chlorophyll a biomass and accrual rates the most in the downstream reach containing all three focal consumers in the presence of fish predators. Consumers also caused the greatest increase in leaf decay rates in the upstream reach containing only killifish and crabs. In the downstream reach where guppies co-occur with predators, we found significantly lower benthic invertebrate biomass in control relative to exclosure treatments than the midstream reach where guppies occur in the absence of predators. These data suggest that differences in guppy foraging, potentially driven by differences in their life history phenotype, may affect ecosystem structure and processes as much as their presence or absence and that interactions among consumers may further mediate their effects in these stream ecosystems.

Published
2012

31. Environmental and organismal predictors of intraspecific variation in the stoichiometry of a neotropical freshwater fish.

Author

El-Sabaawi, Rana W, Kohler, Tyler J, Zandoná, Eugenia, Travis, Joseph, Marshall, Michael C, Thomas, Steven A, Reznick, David N, Walsh, Matthew, Gilliam, James F, Pringle, Catherine, and Flecker, Alexander S

Subjects
Animals, Fishes, Body Size, Environment, Ecosystem, Fresh Water, General Science & Technology
Abstract

The elemental composition of animals, or their organismal stoichiometry, is thought to constrain their contribution to nutrient recycling, their interactions with other animals, and their demographic rates. Factors that affect organismal stoichiometry are generally poorly understood, but likely reflect elemental investments in morphological features and life history traits, acting in concert with the environmental availability of elements. We assessed the relative contribution of organismal traits and environmental variability to the stoichiometry of an insectivorous Neotropical stream fish, Rivulus hartii. We characterized the influence of body size, life history phenotype, stage of maturity, and environmental variability on organismal stoichiometry in 6 streams that differ in a broad suite of environmental variables. The elemental composition of R. hartii was variable, and overlapped with the wide range of elemental composition documented across freshwater fish taxa. Average %P composition was ∼3.2%(±0.6), average %N∼10.7%(±0.9), and average %C∼41.7%(±3.1). Streams were the strongest predictor of organismal stoichiometry, and explained up to 18% of the overall variance. This effect appeared to be largely explained by variability in quality of basal resources such as epilithon N:P and benthic organic matter C:N, along with variability in invertebrate standing stocks, an important food source for R. hartii. Organismal traits were weak predictors of organismal stoichiometry in this species, explaining when combined up to 7% of the overall variance in stoichiometry. Body size was significantly and positively correlated with %P, and negatively with N:P, and C:P, and life history phenotype was significantly correlated with %C, %P, C:P and C:N. Our study suggests that spatial variability in elemental availability is more strongly correlated with organismal stoichiometry than organismal traits, and suggests that the stoichiometry of carnivores may not be completely buffered from environmental variability. We discuss the relevance of these findings to ecological stoichiometry theory.

Published
2012

35. A global database of nitrogen and phosphorus excretion rates of aquatic animals

Author

Vanni, Michael J., McIntyre, Peter B., Allen, Dennis, Arnott, Diane L., Benstead, Jonathan P., Berg, David J., Brabrand, Åge, Brosse, Sébastien, Bukaveckas, Paul A., Caliman, Adriano, Capps, Krista A., Carneiro, Luciana S., Chadwick, Nanette E., Christian, Alan D., Clarke, Andrew, Conroy, Joseph D., Cross, Wyatt F., Culver, David A., Dalton, Christopher M., Devine, Jennifer A., Domine, Leah M., Evans-White, Michelle A., Faafeng, Bjørn A., Flecker, Alexander S., Gido, Keith B., Godinot, Claire, Guariento, Rafael D., Haertel-Borer, Susanne, Hall, Robert O., Henry, Raoul, Herwig, Brian R., Hicks, Brendan J., Higgins, Karen A., Hood, James M., Hopton, Matthew E., Ikeda, Tsutomu, James, William F., Jansen, Henrice M., Johnson, Cody R., Koch, Benjamin J., Lamberti, Gary A., Lessard-Pilon, Stephanie, Maerz, John C., Mather, Martha E., McManamay, Ryan A., Milanovich, Joseph R., Morgan, Dai K. J., Moslemi, Jennifer M., Naddafi, Rahmat, Nilssen, Jens Petter, Pagano, Marc, Pilati, Alberto, Post, David M., Roopin, Modi, Rugenski, Amanda T., Schaus, Maynard H., Shostell, Joseph, Small, Gaston E., Solomon, Christopher T., Sterrett, Sean C., Strand, Øivind, Tarvainen, Marjo, Taylor, Jason M., Torres-Gerald, Lisette E., Turner, Caroline B., Urabe, Jotaro, Uye, Shin-Ichi, Ventelä, Anne-Mari, Villeger, Sébastien, Whiles, Matt R., Wilhelm, Frank M., Wilson, Henry F., Xenopoulos, Marguerite A., and Zimmer, Kyle D.

Published
2017

46. Biotic and abiotic variables influencing plant litter breakdown in streams: a global study

Author

Boyero, Luz, Pearson, Richard G., Hui, Cang, Gessner, Mark O., Pérez, Javier, Alexandrou, Markos A., Graça, Manuel A. S., Cardinale, Bradley J., Albariño, Ricardo J., Arunachalam, Muthukumarasamy, Barmuta, Leon A., Boulton, Andrew J., Bruder, Andreas, Callisto, Marcos, Chauvet, Eric, Death, Russell G., Dudgeon, David, Encalada, Andrea C., Ferreira, Verónica, Figueroa, Ricardo, Flecker, Alexander S., Gonçalves, José F., Helson, Julie, Iwata, Tomoya, Jinggut, Tajang, Mathooko, Jude, Mathuriau, Catherine, M'Erimba, Charles, Moretti, Marcelo S., Pringle, Catherine M., Ramírez, Alonso, Ratnarajah, Lavenia, Rincon, José, and Yule, Catherine M.

Published
2016

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