scholarly journals BODY SIZE AND TROPHIC POSITION IN A DIVERSE TROPICAL FOOD WEB

Ecology ◽  
2005 ◽  
Vol 86 (9) ◽  
pp. 2530-2535 ◽  
Author(s):  
Craig A. Layman ◽  
Kirk O. Winemiller ◽  
D. Albrey Arrington ◽  
David B. Jepsen
Keyword(s):  
Body Size ◽  
Food Web ◽  
Trophic Position

Food web structure and body size: trophic position and resource acquisition

Oikos ◽  
2010 ◽  
Vol 119 (1) ◽  
pp. 147-153 ◽  
Author(s):  
Matías Arim ◽  
Sebastián R. Abades ◽  
Gabriel Laufer ◽  
Marcelo Loureiro ◽  
Pablo A. Marquet
Keyword(s):  
Body Size ◽  
Food Web ◽  
Trophic Position ◽  
Resource Acquisition ◽  
Food Web Structure ◽  
Web Structure

Body size and trophic position in a temperate estuarine food web

2008 ◽  
Vol 33 (2) ◽  
pp. 144-153 ◽  
Author(s):  
Senol Akin ◽  
K.O. Winemiller
Keyword(s):  
Body Size ◽  
Food Web ◽  
Trophic Position

Trophic position scales positively with body size within but not among four species of rocky reef predators

2020 ◽  
Vol 640 ◽  
pp. 189-200 ◽  
Author(s):  
AM Olson ◽  
A Frid ◽  
JBQ dos Santos ◽  
F Juanes
Keyword(s):  
Body Size ◽  
Trophic Position ◽  
Stomach Contents ◽  
Rocky Reef ◽  
Morphometric Traits ◽  
Predator Species ◽  
Predatory Fishes ◽  
Average Size ◽  
Interspecific Comparisons ◽  
Large Predators

Intra- and interspecifically, larger-bodied predators generally occupy higher trophic positions (TPs). With widespread declines in large predators, there is a need to understand their size-based trophic roles to predict ecosystem-level responses. In British Columbia, Canada, we examined size-based trophic interactions between predatory fishes—3 rockfish species (genus Sebastes) and lingcod Ophiodon elongatus—and their prey, converting predator δ15N signatures to TP and analyzing stomach contents. Intraspecifically, TP scaled positively with predator length and gape width, but the rates of change varied by species. Interspecifically, TP did not scale positively with the observed mean sizes or known maximum sizes of species. Lingcod TP was lower than that of yelloweye and quillback rockfishes, which were 51 and 37%, respectively, smaller than lingcod. Yellowtail rockfish had the smallest average size, yet their mean TP did not differ significantly from that of lingcod. Neither species differences in some morphometric traits known to influence body size-TP relationships nor phylogenetic history explained these results. Most prey consumed were <20% of the predator’s size, which might partially explain the lack of a size-based trophic hierarchy among species. Currently, large size classes of rockfishes are being lost due to fisheries and perhaps climate-driven changes. Our findings on intraspecific size-TP relationships indicate that fishery removals of large individuals may diminish trophic structures. Interspecific comparisons of TP suggest that, along with size, species remain an important factor in understanding trophic dynamics. In addition, smaller-bodied predator species may have significant ecological roles to be considered in ecosystem-based fisheries management.

scholarly journals The isotopic niche of Atlantic, biting marine mammals and its relationship to skull morphology and body size

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Massimiliano Drago ◽  
Marco Signaroli ◽  
Meica Valdivia ◽  
Enrique M. González ◽  
Asunción Borrell ◽  
...  
Keyword(s):  
Body Size ◽  
Atlantic Ocean ◽  
Fisheries Management ◽  
Marine Mammals ◽  
Trophic Position ◽  
Sympatric Species ◽  
Isotopic Niche ◽  
Apex Predators ◽  
Skull Morphology ◽  
Ecosystem Based Fisheries Management

AbstractUnderstanding the trophic niches of marine apex predators is necessary to understand interactions between species and to achieve sustainable, ecosystem-based fisheries management. Here, we review the stable carbon and nitrogen isotope ratios for biting marine mammals inhabiting the Atlantic Ocean to test the hypothesis that the relative position of each species within the isospace is rather invariant and that common and predictable patterns of resource partitioning exists because of constrains imposed by body size and skull morphology. Furthermore, we analyze in detail two species-rich communities to test the hypotheses that marine mammals are gape limited and that trophic position increases with gape size. The isotopic niches of species were highly consistent across regions and the topology of the community within the isospace was well conserved across the Atlantic Ocean. Furthermore, pinnipeds exhibited a much lower diversity of isotopic niches than odontocetes. Results also revealed body size as a poor predictor of the isotopic niche, a modest role of skull morphology in determining it, no evidence of gape limitation and little overlap in the isotopic niche of sympatric species. The overall evidence suggests limited trophic flexibility for most species and low ecological redundancy, which should be considered for ecosystem-based fisheries management.

scholarly journals Phylogeny versus body size as determinants of food web structure

2012 ◽  
Vol 279 (1741) ◽  
pp. 3291-3297 ◽  
Author(s):  
Russell E. Naisbit ◽  
Rudolf P. Rohr ◽  
Axel G. Rossberg ◽  
Patrik Kehrli ◽  
Louis-Félix Bersier
Keyword(s):  
Body Size ◽  
Food Web ◽  
Food Webs ◽  
Phylogenetic Signal ◽  
Theoretical Models ◽  
Conservation Priorities ◽  
Food Web Structure ◽  
Web Architecture ◽  
Species Overlap ◽  
Using Data

Food webs are the complex networks of trophic interactions that stoke the metabolic fires of life. To understand what structures these interactions in natural communities, ecologists have developed simple models to capture their main architectural features. However, apparently realistic food webs can be generated by models invoking either predator–prey body-size hierarchies or evolutionary constraints as structuring mechanisms. As a result, this approach has not conclusively revealed which factors are the most important. Here we cut to the heart of this debate by directly comparing the influence of phylogeny and body size on food web architecture. Using data from 13 food webs compiled by direct observation, we confirm the importance of both factors. Nevertheless, phylogeny dominates in most networks. Moreover, path analysis reveals that the size-independent direct effect of phylogeny on trophic structure typically outweighs the indirect effect that could be captured by considering body size alone. Furthermore, the phylogenetic signal is asymmetric: closely related species overlap in their set of consumers far more than in their set of resources. This is at odds with several food web models, which take only the view-point of consumers when assigning interactions. The echo of evolutionary history clearly resonates through current food webs, with implications for our theoretical models and conservation priorities.

scholarly journals Dispersal strategies of juvenile pike ( Esox lucius L.): Influences and consequences for body size, somatic growth and trophic position

2019 ◽  
Vol 29 (2) ◽  
pp. 377-383
Author(s):  
Marina J. Nyqvist ◽  
Julien Cucherousset ◽  
Rodolphe E. Gozlan ◽  
William R.C. Beaumont ◽  
J. Robert Britton
Keyword(s):  
Body Size ◽  
Trophic Position ◽  
Somatic Growth ◽  
Esox Lucius ◽  
Pike Esox Lucius

scholarly journals Responses of food web to hypolimnetic aeration in Lake Vesijärvi

Hydrobiologia ◽  
2020 ◽  
Vol 847 (21) ◽  
pp. 4503-4523 ◽  
Author(s):  
Jukka Ruuhijärvi ◽  
Tommi Malinen ◽  
Kirsi Kuoppamäki ◽  
Pasi Ala-Opas ◽  
Mika Vinni
Keyword(s):  
Body Size ◽  
Food Web ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Perca Fluviatilis ◽  
Fish Predation ◽  
Filamentous Cyanobacteria ◽  
Low Oxygen ◽  
High Quality ◽  
Oxygen Conditions

AbstractWe studied the responses of a food web, especially fish and zooplankton, to summertime aeration, pumping of oxygen-rich epilimnetic water to the hypolimnion in Lake Vesijärvi, southern Finland. The aim of hypolimnetic aeration was to reduce internal loading of phosphorus from sediment. The population of smelt (Osmerus eperlanus L.), the main planktivore of the pelagial area, collapsed during the two 1st years of aeration due to increased temperature and low oxygen concentrations in the hypolimnion. The population recovered after the 4th year of hypolimnetic aeration, when oxygen conditions were improved. Despite elevated hypolimnetic temperature, smelt reached exceptionally high abundance, which led to a significant reduction in cladoceran body size. The density of perch (Perca fluviatilis L.) increased at first, but then decreased when the proportion of smelt and cyprinids increased. Biomasses of Daphnia decreased probably as a result of the disappearance of dark, low-oxygen deep-water refuge against fish predation and low availability of nutritionally high-quality algae. Occasionally filamentous cyanobacteria, such as turbulence tolerant Planktothrix agardhii (Gomont), were abundant, suggesting deteriorated food resources for zooplankton. The responses of food web were controversial with respect to the aim of the management, which was to prevent the occurrence of harmful algal blooms.

Ecophysiological determinants of the variation in 137Cs concentrations between and within lacustrine fish populations

2005 ◽  
Vol 62 (12) ◽  
pp. 2727-2739 ◽  
Author(s):  
Marcus Sundbom ◽  
Markus Meili
Keyword(s):  
Body Size ◽  
Trophic Position ◽  
Fish Populations ◽  
Chernobyl Fallout ◽  
Population Means ◽  
Activity Concentrations ◽  
Resource Specialization ◽  
Total Variability ◽  
Biomagnification Factors ◽  
Fish Trophic Position

One decade after the Chernobyl fallout, the variability of 137Cs activity concentrations among fish within a Swedish lake was >20-fold based on 1361 individuals from seven species collected continually during 1996–1999. Of the total variability, 64% was due to differences between species but only 7% due to temporal variation, which was 1.3-fold for the whole community and 1.3- to 2-fold for population means. Contamination increased with body size (0.6- to 6-fold) and decreased with body condition in most species (1.3-fold). Body size and time together accounted for about half of the total variation within populations. Fish 137Cs was related to differences in feeding ecology, both between and within populations. Biomagnification factors ranged from 2.4 to 5.8. Contamination was highest in piscivorous populations and individuals, intermediate in herbivores and zooplanktivores, and lowest in fish specialized in benthic invertebrates despite their association with contaminated sediments. The 137Cs variance within populations was not correlated with their niche width but moderately positively correlated with fish trophic position and strongly positively correlated with functional omnivory (diversity in prey 137Cs). We conclude that individual resource specialization is an important source of variation in 137Cs concentrations within fish populations.

scholarly journals Examining predator–prey body size, trophic level and body mass across marine and terrestrial mammals

2014 ◽  
Vol 281 (1797) ◽  
pp. 20142103 ◽  
Author(s):  
Marlee A. Tucker ◽  
Tracey L. Rogers
Keyword(s):  
Community Structure ◽  
Body Size ◽  
Body Mass ◽  
Marine Environment ◽  
Trophic Level ◽  
Marine Mammals ◽  
Trophic Position ◽  
Trophic Levels ◽  
Predator Prey ◽  
Terrestrial Mammals

Predator–prey relationships and trophic levels are indicators of community structure, and are important for monitoring ecosystem changes. Mammals colonized the marine environment on seven separate occasions, which resulted in differences in species' physiology, morphology and behaviour. It is likely that these changes have had a major effect upon predator–prey relationships and trophic position; however, the effect of environment is yet to be clarified. We compiled a dataset, based on the literature, to explore the relationship between body mass, trophic level and predator–prey ratio across terrestrial ( n = 51) and marine ( n = 56) mammals. We did not find the expected positive relationship between trophic level and body mass, but we did find that marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Also, marine mammals are largely carnivorous and have significantly larger predator–prey ratios compared with their terrestrial counterparts. We propose that primary productivity, and its availability, is important for mammalian trophic structure and body size. Also, energy flow and community structure in the marine environment are influenced by differences in energy efficiency and increased food web stability. Enhancing our knowledge of feeding ecology in mammals has the potential to provide insights into the structure and functioning of marine and terrestrial communities.

scholarly journals Body size and mobility explain species centralities in the Gulf of California food web

2019 ◽  
Vol 20 (2) ◽  
pp. 149-160 ◽  
Author(s):  
R. Olmo Gilabert ◽  
A. F. Navia ◽  
G. De La Cruz-Agüero ◽  
J. C. Molinero ◽  
U. Sommer ◽  
...  
Keyword(s):  
Body Size ◽  
Food Web ◽  
Gulf Of California
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