Rana El-Sabaawi

Rana El-Sabaawi
University of Victoria | UVIC · Department of Biology

Doctor of Philosophy

About

83
Publications
17,269
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1,484
Citations
Citations since 2016
49 Research Items
1214 Citations
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2016201720182019202020212022050100150200
2016201720182019202020212022050100150200

Publications

Publications (83)
Article
Full-text available
The threespine stickleback ( Gasterosteus aculeatus ) is an important model for studying the evolution of vertebrate morphology. Sticklebacks inhabit freshwater, brackish, and marine northern hemisphere waters. Anadromous and marine populations (hereafter marine) are assumed to have remained unchanged morphologically from ancestral marine stickleba...
Article
Full-text available
Urbanization transforms natural and agricultural areas into built landscapes. Such profound habitat alteration imposes strong pressure on phenotypic trait changes through processes related to natural and/or sexual selection. Evidence of how natural selection drives changes to traits in urban biota is increasing, but little is known about the role o...
Article
Full-text available
The Neotropical region hosts 4,225 freshwater fish species, ranking first among the world’s most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north, to the sout...
Article
Full-text available
Generalist species dominate urban ecosystems. The success of urban generalists is often related to a plastic diet and feeding traits that allow them to take advantage of a variety of food resources provided by humans in cities. The classification of a species as a generalist is commonly based on mean estimates of diet-and feeding-related traits. Ho...
Article
Full-text available
Marine‐derived resource subsidies can generate intrapopulation variation in the behaviors and diets of terrestrial consumers. How omnivores respond, given their multiple trophic interactions, is not well understood. We sampled mice (Peromyscus keeni) and their food sources at five sites on three islands of the Central Coast of British Columbia, Can...
Article
Full-text available
The effects of invaders on native species are usually tested using species mean trait values over long time scales. However, considering individual variation over short timescales can help us better understand the interaction between invaders and native species. We compared trophic traits of the non-native guppy (Poecilia reticulata) and the native...
Data
Many species extend their range by moving to new localities. A newly arrived species may generate ecological consequences as a result of its traits, but also as a result of the characteristics of the recipient ecosystem. Teasing apart the relative contribution of each of these two components is difficult because colonization events are typically st...
Article
Full-text available
The ecological consequences of biological range extensions reflect the interplay between the functional characteristics of the newly arrived species and their recipient ecosystems. Teasing apart the relative contribution of each component is difficult because most colonization events are studied retrospectively, i.e., after a species became establi...
Article
Microplastic particles (MPs) occur widely in aquatic ecosystems and are ingested by a wide range of organisms. While trophic transfer of MPs is known to occur, researchers do not yet fully understand the fate of MPs in food webs. We explored the factors influencing reported ingestion of MPs in marine and freshwater fishes by conducting a literature...
Article
Full-text available
Climate change is expected to alter precipitation patterns worldwide, which can have direct effects on streamflow dynamics. In many tropical regions, climate-driven changes in rainfall are predicted to decrease streamflow and increase flash flooding, but the implications of these changes for stream ecosystem function are poorly understood. We used...
Article
We know that it can be tough to be a person of colour working in ecology and evolution. Here is what has worked for us.
Article
Full-text available
1- Alien species often flourish and become invasive in urban ecosystems. How and why invaders succeed in urban systems is an important, yet poorly understood, question. We investigate whether the success of urban invaders is related to changes in species traits that enhance invasive potential. We also explore whether a trophic mechanism helps expla...
Article
Full-text available
Connecting the selective forces that drive the evolution of phenotypes to their underlying genotypes is key to understanding adaptation, but such connections are rarely tested experimentally. Threespine stickleback (Gasterosteus aculeatus ) are a powerful model for such tests because genotypes that underlie putatively adaptive traits have been iden...
Article
Full-text available
Understanding how nutrients flow through food webs is central in ecosystem ecology. Tracer addition experiments are powerful tools to reconstruct nutrient flows by adding an isotopically enriched element into an ecosystem and tracking its fate through time. Historically, the design and analysis of tracer studies have varied widely, ranging from des...
Article
Full-text available
The rapid expansion of urban centers is a critical threat to stream ecosystems, yet we currently lack mechanistic understanding of the effects of urbanization on stream communities. Here we explore how an intraspecific trait perspective can unveil mechanisms of change in urban stream communities. Intraspecific trait approaches are rarely used in ur...
Article
Full-text available
Climate change is expected to alter precipitation patterns worldwide, which will affect streamflow in riverine ecosystems. It is vital to understand the impacts of projected flow variations, especially in tropical regions where the effects of climate change are expected to be one of the earliest to emerge. Space‐for‐time substitutions have been suc...
Article
Full-text available
Urban streams are impacted by invasion of exotic riparian plants and the accumulation of plastic trash, which alter in-stream litter subsidies, and cause changes that cascade up the aquatic food web. The impacts of these factors on urban streams is poorly understood. We compared decay rates and invertebrate colonizers of 5 litter pack types in 4 ur...
Conference Paper
Full-text available
The guppy, Poecilia reticulata, is a small stream fish that was introduced worldwide mainly for mosquito control. However, there is no consensus on how efficiently guppies feed on mosquito. In Brazil, guppies co-occur in streams with two closely related native species: Poecilia vivipara and Phalloceros harpagos. In this study we compare the diet of...
Article
1.The human population is rapidly urbanizing, and the negative impacts of urban cover on biodiversity and ecosystem function are expected to increase. Trophic dynamics have been hypothesized to change with urbanization, with consequences for biodiversity and function. Here I review recent progress in this area by focusing on how urbanization affect...
Article
Full-text available
The early marine period is a critical life history stage for growth and survival of anadromous juvenile Pacific salmon. The integrity of nearshore ecosystems where juvenile salmon reside and the capacity of these habitats to provide prey can thus influence overall salmon returns. Eelgrass Zostera marina beds in particular are considered critical ne...
Article
The evolutionary consequences of temporal variation in selection remain hotly debated. We explored these consequences by studying threespine stickleback in a set of bar-built estuaries along the central California coast. In most years, heavy rains induce water flow strong enough to break through isolating sand bars, connecting streams to the ocean....
Article
Full-text available
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 th...
Article
Full-text available
In many contexts, nutrient excretion by consumers can impact ecosystems by altering the availability of limiting nutrients. Variation in nutrient excretion can be predicted by mass balance models, most of which are premised on two key ideas: (1) consumers maintain fixed whole-body nutrient content (i.e., %N and %P), so-called fixed homeostasis; (2)...
Data
Dietary phosphorus requirements. List of ingredients used to make guppy diets used in this study. (DOCX)
Data
Detailed statistical results. Series of tables showing specific model comparisons used to support inferences made in this study. (DOCX)
Data
River-specific analysis. Series of tables showing specific statistical results, separated by river. (DOCX)
Article
Full-text available
Studies of trophic-level material and energy transfers are central to ecology. The use of isotopic tracers has now made it possible to measure trophic transfer efficiencies of important nutrients and to better understand how these materials move through food webs. We analyzed data from thirteen (15) N-ammonium tracer addition experiments to quantif...
Article
Much of the recent progress in the study of eco-evolutionary dynamics has occurred in fish models. In this review, I focus specifically on the mechanisms by which fish evolution affects ecological processes, highlighting outstanding questions and new frontiers. Fish evolution can alter the ecology of individuals by changing traits that underlie res...
Article
Full-text available
Interspecific variation in elemental composition is well known and often leads to predictable differences in ecosystem interactions, but little is known about the extent, causes and importance of intraspecific variation in elemental composition. If intraspecific variation is substantial and has a genetic basis, it may underlie an important mechanis...
Article
Full-text available
The theories developed in ecological stoichiometry are fundamentally based on traits. On the one hand, traits directly linked to cell/body stoichiometry, such as nutrient uptake and storage traits, as well as the associated trade-offs, have the potential to shape ecological interactions such as competition and predation within ecosystems. On the ot...
Article
Full-text available
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...
Article
Full-text available
Long viewed as a mostly noble, atmospheric species, recent work demonstrates that nitrogen in fact cycles throughout the Earth system, including the atmosphere, biosphere, oceans, and solid Earth. Despite this new-found behaviour, more thorough investigation of N in geologic materials is limited due to its low concentration (one to tens of parts pe...
Article
• Streams are reliant on streamside plants for allochthonous inputs that form the base of the stream food web. The impact of exotic leaves on stream ecosystems has been investigated regionally, but not assessed globally. In this study, we conducted a global meta‐analysis contrasting native and exotic aquatic litter decay. • We used a linear mixed e...
Article
Full-text available
Phenotypes can both evolve in response to, and affect, ecosystem change, but few examples of diverging ecosystem-effect traits have been investigated. Bony armor traits of fish are good candidates for this because they evolve rapidly in some freshwater fish populations, and bone is phosphorus rich and likely to affect nutrient recycling in aquatic...
Article
Full-text available
Long viewed as a mostly noble, atmospheric species, recent work demonstrates that nitrogen in fact cycles throughout the Earth system, including the atmosphere, biosphere, oceans, and solid Earth. Despite this new-found behaviour, more thorough investigation of N in geologic materials is limited due to its low concentration (1 to 10 s ppm) and diff...
Article
Full-text available
Deploying mosquito predators such as the guppy (Poecilia reticulata) into bodies of water where mosquitoes breed is a common strategy for limiting the spread of disease-carrying mosquitoes. Here, we draw on studies from epidemiology, conservation, ecology and evolution to show that the evidence for the effectiveness of guppies in controlling mosqui...
Article
Full-text available
Understanding how trait diversification alters ecosystem processes is an important goal for ecological and evolutionary studies. Ecological stoichiometry provides a framework for predicting how traits affect ecosystem function. The growth rate hypothesis of ecological stoichiometry links growth and phosphorus (P) body composition in taxa where nucl...
Article
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 presen...
Article
1.Spatial resource subsidies can alter bottom-up and top-down forces of community regulation across ecosystem boundaries. Most subsidies are temporally variable, and recent theory has suggested that consumer-resource dynamics can be stabilized if the peak timing of a subsidy is desynchronized with that of prey productivity in the recipient ecosyste...
Article
Full-text available
1) Ontogenetic niche shifts are widely prevalent in nature and are important in shaping the structure and dynamics of ecosystems. Stable isotope analysis is a powerful tool to assess these shifts, with δ15N providing a measure of trophic level and δ13C a measure of energy source. 2) Previous applications of stable isotopes to study ontogenetic nic...
Article
Full-text available
The field of urban stream ecology has evolved rapidly in the last 3 decades, and it now includes natural scientists from numerous disciplines working with social scientists, landscape planners and designers, and land and water managers to address complex, socioecological problems that have manifested in urban landscapes. Over the last decade, strea...
Article
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Research in eco-evolutionary dynamics and community genetics has demonstrated that variation within a species can have strong impacts on associated communities and ecosystem processes. Yet, these studies have centred around individual focal species and at single trophic levels, ignoring the role of phenotypic variation in multiple taxa within an ec...
Article
Full-text available
Evolution of life history traits can occur rapidly and has the potential to influence ecological processes, which can also be shaped by abiotic and biotic factors. Few studies have shown that life history phenotype can affect ecological processes as much as commonly studied biotic ecological variables, but currently we do not know how the ecologica...
Article
Trait evolution can occur in response to anthropogenic alterations to ecosystems and can occur on timescales similar to those of ecological processes suggesting that it could alter ecosystem function. In this study, we characterise the effects of life history evolution on nutrient recycling using the Trinidadian guppy (Poecilia reticulata) as a mod...
Article
Full-text available
A trophic niche shift can occur as an adaptive response to environmental change such as altered resource quality, abundance or composition. Alterations in digestive traits such as gut morphology and physiology may enable these niche shifts and affect the persistence of populations and species. Relatively few studies, however, have assessed how nich...
Article
Analyses of 21 N-15 stable isotope tracer experiments, designed to examine food web dynamics in streams around the world, indicated that the isotopic composition of food resources assimilated by primary consumers (mostly invertebrates) poorly reflected the presumed food sources. Modeling indicated that consumers assimilated only 33-50% of the N ava...
Article
Full-text available
A ‘genes-to-ecosystems’ approach has been proposed as a novel avenue for integrating the consequences of intraspecific genetic variation with the underlying genetic architecture of a species in order to shed light on the relationships among hierarchies of ecological organization (genes individuals communities ecosystems). However, attempts to ident...
Conference Paper
Full-text available
Background/Question/Methods Local adaptation, defined as when individuals evolve towards an optimal phenotype within a given environment, has been shown to be an important component of niche specialization and speciation. There is growing evidence that the phenotypic variation that corresponds from adaptation can also have consequences for the as...
Article
Full-text available
Interspecific differences in organismal stoichiometry (OS) have been documented in a wide range of animal taxa and are of significant interest for understanding evolutionary patterns in OS. In contrast, intraspecific variation in animal OS has generally been treated as analytical noise or random variation, even though available data suggest intrasp...
Article
Full-text available
ABSTRACT: The bi-directional movements of materials, nutrients and energy across the land−sea interface result in a number of ecological consequences. Migratory animals that move across eco- systems drive a number of these spatial subsidies (e.g. anadromous salmon), but many of the world’s animal migrations are in decline. The cross-ecosystem reach...
Conference Paper
Background/Question/Methods Resource subsides moving across habitat boundaries can have profound consequences in recipient communities and ecosystems. Accumulating evidence suggests that inputs of resource subsidies are temporally variable (i.e., pulsed). Theory has predicted that seasonal timing of the pulsed subsidies can be a critical componen...
Article
Full-text available
Understanding how environmental ‘‘bottom-up’’ conditions affect the production or survival of higher trophic levels is an integral component of ecosystem management. However, linking environmental conditions to higher trophic levels is difficult because of differences in turnover time. Carbon (d13C) and nitrogen (d15N) isotopes in animal tissues ca...
Article
We have compiled and archived a large fraction of the zooplankton data collected from the Strait of Georgia during the past 50 years. Although the full dataset is very heterogeneous and gappy, sampling since 1990 has been consistent and frequent enough to examine interannual variability of the full zooplankton community. In this paper we focus on d...
Article
Full-text available
Light, nutrient availability, and flow are strong factors controlling the elemental composition and biomass of epilithon in temperate stream ecosystems. However, comparatively little is known about these relationships in tropical streams. We investigated how gradients of light and nutrient availability, seasonality, and habitat influenced epilithon...
Article
Full-text available
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 excl...
Data
Statistical methods for split-plot design and analytical framework for structural and process responses. (DOC)
Data
Benthic invertebrate tallies for control and electrified treatments in three reaches. (DOC)
Conference Paper
Background/Question/Methods Changes in consumer assemblages caused by species invasions or losses have significant effects on ecosystem function. These perturbations can also alter organismal phenotypes, but the ecosystem consequences of phenotypic variability are largely unexplored. How important are the ecosystem effects of phenotypic diversifi...
Conference Paper
Background/Question/Methods Each year along the Pacific coast of North America, Pacific herring (Clupea pallasi) aggregate and spawn in the nearshore and intertidal. Although ephemeral, these spawn events often represent extremely large aggregations of biomass and energy, a portion of which is transferred to intertidal ecosystems. This input of he...
Article
Full-text available
1. Ecological stoichiometry expresses ecological interactions as the balance between multiple elements. It relates the ecological function of organisms to their elemental composition, or their organismal stoichiometry. Organismal stoichiometry is thought to reflect elemental investments in life history and morphology acting in concert with variabil...
Article
Full-text available
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 feature...
Data
Sampling of environmental variables and basal resource quality. (DOC)
Data
Average stoichiometry of epilithon and benthic organic matter (BOM) collected from each site. (DOC)
Data
Least squares (LS) means generated by the stage of maturity×community interaction. (DOCX)
Article
Full-text available
Nutrient limitation plays an important role in shaping community structure and ecosystem processes in aquatic environments. Many types of nutrient diffusing substrata (NDS) have been used to estimate nutrient limitation in lotic systems. However, whether these various NDS methods produce comparable results is unknown. We evaluated the 3 most common...