Structure of tropical river food webs revealed by stable isotope ratios

  title={Structure of tropical river food webs revealed by stable isotope ratios},
  author={David B. Jepsen and Kirk O. Winemiller},
Fish assemblages in tropical river food webs are characterized by high taxonomic diversity, diverse foraging modes, omnivory, and an abundance of detritivores. Feeding links are complex and modified by hydrologic seasonality and system productivity. These properties make it difficult to generalize about feeding relationships and to identify dominant linkages of energy flow. We analyzed the stable carbon and nitrogen isotope ratios of 276 fishes and other food web components living in four… 

Figures and Tables from this paper

Isotopic trophic guild structure of a diverse subtropical South American fish community

Although community-level isotopic overlap was high, trophic guilds and taxonomic groups can be clearly differentiated using stable isotope ratios and the relative importance of basal resources supporting fish biomass is estimated.

Food web structure of a Pantanal shallow lake revealed by stable isotopes

Food webs are good ecological macro-descriptors and their study is important in ecology in understanding nutrient cycles, tracing and quantifying energy and in describing trophic interactions within

Food Web Structure and Trophic Interactions Revealed by Stable Isotope Analysis in the Midstream of the Chishui River, a Tributary of the Yangtze River, China

The autochthonous productivity, stable trophic niche structure, multiple Trophic pathways and long food chain length found here demonstrate its high conservation value, and the strategy to refrain from damming on this river should persist into the future.

Trophic structure of a floodplain fish assemblage in the upper Amazon basin, Bolivia

The fact that detritivore fishes, the most abundant food source for piscivores, occupy relatively high TPs determines that food chains in these particular Amazonian floodplains are longer than previously thought.

A Seasonally Dynamic Estuarine Ecosystem Provides a Diverse Prey Base for Elasmobranchs

It is shown that riverine food webs can display complex spatiotemporal variations in trophic structure and that coastal and euryhaline mobile elasmobranchs forage in a range of coastal and freshwater habitats, demonstrating their influence on these food webs.

Trophic Variation in Coastal Plain Stream Predatory Fishes

Differences between the observed patterns and other published accounts indicate further evaluation of trophic patterns of these fishes among habitats is warranted, including Largemouth Bass and Longnose Gar.

Omnivory and Opportunism Characterize Food Webs in a Large Dry-Tropics River System

Abstract: We analyzed basal sources, trophic levels, and connectance in dry-season food webs on 4 rivers in the upper Burdekin catchment in the dry tropics of northeastern Australia. The region is

Foodweb structure in small streams: do we need different models for the tropics?

Gut-content analyses and stable-isotope signatures were used to characterize feeding relationships and foodweb attributes of benthic communities in riffles in 2 forest streams in Hong Kong, finding marked differences in the degree of omnivory and dominance of tropical stream food webs by macroconsumers.

Energy flow and the trophic basis of macroinvertebrate and amphibian production in a neotropical stream food web

This is the first study to provide quantitative estimates of energy flow through a neotropical stream food web and Omnivory was prevalent across all functional groups, particularly predators, suggesting traditional functional and trophic assignments based on temperate regions may not be appropriate for tropical systems.

Investigating the trophic ecology of freshwater fish communities from central and eastern Indian streams using stable isotope analysis

Stable isotope analysis (SIA) has been used over the last decade to decipher trophic relationships between organisms, especially in freshwater and marine systems. Using SIA to understand food web



Stable Isotopes and Planktonic Trophic Structure in Arctic Lakes

It is indicated that only two or three trophic levels exist in the macrozoopolankton of these lakes, in comparison to five or six trophics reported in temperate lakes, and isotope analyses showed that actual food—web structure is poorly predicted from simple consideration of species lists and potential Trophic interactions.

Spatial and Temporal Variation in Tropical Fish Trophic Networks

Four lowland aquatic food webs were investigated over the course of two years, finding that extensive among—site variation in food—web parameters was associated with differences in species richness and environmental differences associated with rainfall patterns, physiography, and gross primary production.

A Stable Isotope Study on Seasonal Food Web Dynamics in a Eutrophic Lake

It is suggested that intensive measurements of carbon and nitrogen isotope ratios of each species serve to effectively assess the yearly dynamics of the food web structure in eutrophic lakes when productivity and species composition of plankton change seasonally.

Effects of seasonality and fish movement on tropical river food webs

Migratory herbivorous fishes originating from eutrophic, productive ecosystems may subsidize resident predators of oligotrophic river ecosystems, which may result in cascading direct and indirect eVects on other species in local food webs.

The importance of omnivory and predator regulation of prey in freshwater fish assemblages of North America

  • R. Vadas
  • Environmental Science
    Environmental Biology of Fishes
  • 2004
Food webs for 15 freshwater ecosystems in North America are reconstructed, based upon fish feeding habits in these ecosystems and established trophic categorizations for aquatic invertebrates, and the data indicate that omnivory is often important in freshwater ecosystems, such that fish may not always control the abundance of their prey.

Fish communities along environmental gradients in a system of tropical streams

SynopsisFish community structure was examined in 9 forested streams (1–6 m wide) in central Panama during dry seasons over a 3 year period. Study regions varied in annual rainfall, degree of canopy

Food partitioning among Lake Malawi nearshore fishes as revealed by stable isotope analyses

Evidence for food resource partitioning among fishes of Lake Malawi, Africa is presented by comparing the stable isotope composition (b13C and b15N) of a number of nearshore fish species and their potential food sources and this approach circumvents many of the problems in stomach analyses noted above.

Comparing trophic position of freshwater fish calculated using stable nitrogen isotope ratios (δ15N) and literature dietary data

Interpreting the delta 15N of aquatic consumers relative to large, long-lived primary consumers such as unionid mussels provides a continuous measure of an organism's trophic position that adjusts for among-system variation in baselineDelta 15N.

Stable Carbon and Nitrogen Isotope Tracers of Trophic Dynamics in Natural Populations and Fisheries of the Lahontan Lake System, Nevada

Carbon isotope ratio measurements clearly illustrated the isotopic similarity between hatchery-raised Lahontan cutthroat trout and cui-ui and the artificial diet, but differed from the δ13C of their wild counterparts consuming natural foods.

Food webs: integration of patterns and dynamics

This work focuses on food-web dynamics on some small subtropical islands and on the interactions of top and intermediate predators, as well as on underappreciated interactions in terrestrial food webs.