Winter Diets of Immature Green Turtles (Chelonia mydas) on a Northern Feeding Ground: Integrating Stomach Contents and Stable Isotope Analyses

2013 ◽  
Vol 37 (4) ◽  
pp. 986-994 ◽  
Author(s):  
Natalie C. Williams ◽  
Karen A. Bjorndal ◽  
Margaret M. Lamont ◽  
Raymond R. Carthy
Keyword(s):  
Stable Isotope ◽  
Stomach Contents ◽  
Chelonia Mydas ◽  
Stable Isotope Analyses ◽  
Green Turtles ◽  
Feeding Ground ◽  
Winter Diets ◽  
Isotope Analyses

scholarly journals Trophic shift in the diet of the pelagic thresher shark based on stomach contents and stable isotope analyses

2013 ◽  
Vol 9 (10) ◽  
pp. 958-971 ◽  
Author(s):  
Carlos Polo-Silva ◽  
Seth D. Newsome ◽  
Felipe Galván-Magaña ◽  
Marcela Grijalba-Bendeck ◽  
Adolfo Sanjuan-Muñoz
Keyword(s):  
Stable Isotope ◽  
Stomach Contents ◽  
Stable Isotope Analyses ◽  
Trophic Shift ◽  
Thresher Shark ◽  
Isotope Analyses

scholarly journals Trophic plasticity in the sea urchin Paracentrotus lividus, as a function of resource availability and habitat features

2020 ◽  
Vol 637 ◽  
pp. 71-85 ◽  
Author(s):  
J Camps-Castellà ◽  
J Romero ◽  
P Prado
Keyword(s):  
Stable Isotope ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Stomach Contents ◽  
Paracentrotus Lividus ◽  
Seagrass Habitat ◽  
Stable Isotope Analyses ◽  
Trophic Plasticity ◽  
Seagrass Meadows ◽  
Isotope Analyses

Factors controlling herbivory pressure are of central importance in shaping the seascape. In the Mediterranean, the sea urchin Paracentrotus lividus is considered as a keystone herbivore in seagrass meadows and macroalgal communities. Here we explored the trophic behavior of this sea urchin in a shallow seagrass habitat of Cymodocea nodosa mixed with Caulerpa prolifera and interspersed with sandy areas in Alfacs Bay, Ebro Delta (NW Mediterranean). The seasonal pseudo-indigenous bryozoan Amathia verticillata is locally very abundant, and there is also an important population of pen shells Pinna nobilis, providing hard substrate and cover, thus being a unique environment for assessing sea urchin trophic behavior. To this end, we conducted an ensemble of food preference and foraging experiments and stomach content and stable isotope analyses. Our results showed that sea urchins strongly prefer A. verticillata over other local resources, and there was also an important presence of the bryozoan in stomach contents (ca. 44%), coupled with green and decayed seagrass leaves. Stable isotope analyses revealed that over the long term, ca. 65% of the diet of P. lividus was based on decayed seagrass leaves, followed by the bryozoan and green seagrass leaves (21.7 and 13.3%, respectively). The local availability of P. nobilis provides a preferred substrate for sea urchins, which showed limited foraging movements into the surrounding seagrass beds, particularly when A. verticillata was attached to the pen shells. The apparently high contribution of animal and detrital food to P. lividus diet is unprecedented, and suggests an opportunistic feeding behavior in sea urchins in those habitats.

scholarly journals Trophic specialization on unique resources in one of the most celebrated examples of sympatric speciation, Barombi Mbo crater lake cichlids

2021 ◽  
Author(s):  
Jacquelyn Galvez ◽  
Keara McLean ◽  
Cyrille Dening Touokong ◽  
LeGrand Nono Gonwouo ◽  
Christopher Martin
Keyword(s):  
Stable Isotope ◽  
Niche Partitioning ◽  
Stomach Contents ◽  
Sympatric Speciation ◽  
Trophic Niche ◽  
Feeding Strategies ◽  
Trophic Specialization ◽  
Dietary Specialization ◽  
Stable Isotope Analyses ◽  
Isotope Analyses

Divergent ecological selection often results in trophic niche partitioning and is one of the central processes underlying sympatric speciation. However, there are still few studies of niche partitioning in putative examples of sympatric speciation in the wild. Here we conducted the first quantitative study of dietary niche partitioning in one of the most celebrated examples of sympatric speciation, Barombi Mbo cichlids, using stomach contents and stable isotope analyses. We found little evidence for trophic niche partitioning among any Barombi Mbo cichlids, even among the nine species coexisting in sympatry in the littoral zone. Stable isotope analyses supported these conclusions of minimal dietary overlap. However, we did find extraordinary dietary specialization in some species, including spongivory and feeding on terrestrial ants, both unique feeding strategies among freshwater fishes. Stomach contents of the spongivore (Pungu maclareni) were 20% freshwater sponge, notable considering that only 0.04% of all fishes consume sponges. Overall, we conclude that while there is less trophic niche partitioning than expected among Barombi Mbo cichlids, there is evidence for dietary specialization on rare resources in support of Liem's paradox.

scholarly journals Individual trophic specialization in juvenile European seabass: implications for the management of a commercially important species

2019 ◽  
Vol 76 (6) ◽  
pp. 1784-1793 ◽  
Author(s):  
Matthew R D Cobain ◽  
Will Steward ◽  
Clive N Trueman ◽  
Antony Jensen
Keyword(s):  
Stable Isotope ◽  
Management Strategies ◽  
Stomach Contents ◽  
Fishing Effort ◽  
Trophic Specialization ◽  
Important Species ◽  
Stable Isotope Analyses ◽  
European Seabass ◽  
Commercially Important ◽  
Isotope Analyses

Abstract Individual differences in diet can play an important role defining a population's ecological niche and its role within food webs and habitats, but individual trophic specialization is rarely considered in a fisheries context. Stocks of European seabass, Dicentrarchus labrax, have declined in recent years, and policy has focused on managing fishing effort. Inshore nursery grounds represent a critical habitat in terms of recruitment to standing stocks, and improved understanding of the ecology of juvenile seabass at the level of the individual may assist the development of management strategies aimed at maximizing their survival and growth. We quantified levels of individual trophic specialization in juvenile seabass using stomach contents and stable isotope analyses at a monthly resolution over an annual cycle. We found significant, seasonally varying levels of individual specialization in stomach contents, with reduced specialization observed in the spring. This was corroborated by stable isotope analyses, where isotopic variance among seabass individuals was significantly higher compared to that in two other concurrently sampled, sympatric bentho-pelagic predators. Our findings suggest that juvenile seabass form trophic-generalist populations composed of specialized individuals. Considering variation in individual behaviours may improve management strategies aimed at protecting the vulnerable life stages of this commercially important species.

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