Compound specific isotope analyses of harp seal teeth: tools for trophic ecology reconstruction

2021 ◽  
Author(s):  
JL Kershaw ◽  
Cd la Vega ◽  
RM Jeffreys ◽  
AK Frie ◽  
T Haug ◽  
...  
Keyword(s):  
Trophic Ecology ◽  
Harp Seal ◽  
Isotope Analyses

Identification of trophic niches of subterranean diving beetles in a calcrete aquifer by DNA and stable isotope analyses

2014 ◽  
Vol 65 (2) ◽  
pp. 95 ◽  
Author(s):  
Tessa M. Bradford ◽  
William F. Humphreys ◽  
Andrew D. Austin ◽  
Steven J. B. Cooper
Keyword(s):  
Stable Isotope ◽  
Trophic Ecology ◽  
Niche Partitioning ◽  
Niche Differentiation ◽  
Trophic Niche ◽  
Coi Gene ◽  
Stable Isotope Analyses ◽  
Prey Preferences ◽  
Diving Beetles ◽  
Isotope Analyses

The Yilgarn calcrete aquifers in Western Australia are an interesting system for investigating the process of speciation within subterranean habitats, because of the limited opportunities for dispersal between isolated calcretes. The presence of different-sized diving beetles (Dytiscidae) in separate calcretes, including sympatric sister-species pairs, suggests that species may have evolved within calcretes by an adaptive shift as a result of ecological-niche differentiation. We have studied the potential for trophic niche partitioning in a sister triplet of diving beetles, of distinctly different sizes, from a single aquifer. Fragments of the mitochondrial COI gene, specific to known species of amphipods and copepods, were polymerase chain reaction-amplified from each of the three beetle species, indicating that there is an overlap in their prey items. Significant differences were found in the detected diets of the three species, and results showed a propensity for prey preferences of amphipods by the large beetles and one species of copepod for the small beetles. A terrestrial source of carbon to the calcrete was suggested by stable isotope analyses. The combined approach of molecular, stable isotope and behavioural studies have provided insight into the trophic ecology of this difficult-to-access environment, providing a framework for more fine-scale analyses of the diet of different-sized species to examine speciation underground.

Trophic ecology ofPomatoschistus micropswithin an intertidal bay (Roscoff, France), investigated through gut content and stable isotope analyses

2013 ◽  
Vol 35 (2) ◽  
pp. 261-270 ◽  
Author(s):  
Jean-Charles Leclerc ◽  
Pascal Riera ◽  
Laure M.-L. J. Noël ◽  
Cédric Leroux ◽  
Ann C. Andersen
Keyword(s):  
Stable Isotope ◽  
Trophic Ecology ◽  
Gut Content ◽  
Stable Isotope Analyses ◽  
Isotope Analyses

scholarly journals Habitat and trophic ecology of Southern Ocean cephalopods from stable isotope analyses

2015 ◽  
Vol 530 ◽  
pp. 119-134 ◽  
Author(s):  
M Guerreiro ◽  
RA Phillips ◽  
Y Cherel ◽  
FR Ceia ◽  
P Alvito ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Southern Ocean ◽  
Trophic Ecology ◽  
Stable Isotope Analyses ◽  
Isotope Analyses

scholarly journals Stable isotope analyses reveal unique trophic role of reef manta rays ( Mobula alfredi ) at a remote coral reef

2019 ◽  
Vol 6 (9) ◽  
pp. 190599 ◽  
Author(s):  
Lauren R. Peel ◽  
Ryan Daly ◽  
Clare A. Keating Daly ◽  
Guy M. W. Stevens ◽  
Shaun P. Collin ◽  
...  
Keyword(s):  
Coral Reef ◽  
Stable Isotope ◽  
Trophic Ecology ◽  
Sample Treatment ◽  
Stable Isotope Analyses ◽  
Isotopic Signatures ◽  
Freeze Dried ◽  
Isotope Analyses ◽  
Trophic Role

Stable isotope analyses provide the means to examine the trophic role of animals in complex food webs. Here, we used stable isotope analyses to characterize the feeding ecology of reef manta rays ( Mobula alfredi ) at a remote coral reef in the Western Indian Ocean. Muscle samples of M. alfredi were collected from D'Arros Island and St. Joseph Atoll, Republic of Seychelles, in November 2016 and 2017. Prior to analysis, lipid and urea extraction procedures were tested on freeze-dried muscle tissue in order to standardize sample treatment protocols for M. alfredi . The lipid extraction procedure was effective at removing both lipids and urea from samples and should be used in future studies of the trophic ecology of this species. The isotopic signatures of nitrogen (δ 15 N) and carbon (δ 13 C) for M. alfredi differed by year, but did not vary by sex or life stage, suggesting that all individuals occupy the same trophic niche at this coral reef. Furthermore, the isotopic signatures for M. alfredi differed to those for co-occurring planktivorous fish species also sampled at D'Arros Island and St. Joseph Atoll, suggesting that the ecological niche of M. alfredi is unique. Pelagic zooplankton were the main contributor (45%) to the diet of M. alfredi , combined with emergent zooplankton (38%) and mesopelagic prey items (17%). Given the extent of movement that would be required to undertake this foraging strategy, individual M. alfredi are implicated as important vectors of nutrient supply around and to the coral reefs surrounding D'Arros Island and St. Joseph Atoll, particularly where substantial site fidelity is displayed by these large elasmobranchs.

scholarly journals The first global deep-sea stable isotope assessment reveals the unique trophic ecology of Vampire Squid Vampyroteuthis infernalis (Cephalopoda)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alexey V. Golikov ◽  
Filipe R. Ceia ◽  
Rushan M. Sabirov ◽  
Jonathan D. Ablett ◽  
Ian G. Gleadall ◽  
...  
Keyword(s):  
Organic Matter ◽  
Stable Isotope ◽  
Deep Sea ◽  
Trophic Ecology ◽  
Global Scale ◽  
Phylogenetic Position ◽  
Relict Species ◽  
Global Comparison ◽  
Vampyroteuthis Infernalis ◽  
Isotope Analyses

AbstractVampyroteuthis infernalis Chun, 1903, is a widely distributed deepwater cephalopod with unique morphology and phylogenetic position. We assessed its habitat and trophic ecology on a global scale via stable isotope analyses of a unique collection of beaks from 104 specimens from the Atlantic, Pacific and Indian Oceans. Cephalopods typically are active predators occupying a high trophic level (TL) and exhibit an ontogenetic increase in δ15N and TL. Our results, presenting the first global comparison for a deep-sea invertebrate, demonstrate that V. infernalis has an ontogenetic decrease in δ15N and TL, coupled with niche broadening. Juveniles are mobile zooplanktivores, while larger Vampyroteuthis are slow-swimming opportunistic consumers and ingest particulate organic matter. Vampyroteuthis infernalis occupies the same TL (3.0–4.3) over its global range and has a unique niche in deep-sea ecosystems. These traits have enabled the success and abundance of this relict species inhabiting the largest ecological realm on the planet.

The trophic ecology of partial migration: insights from Merluccius australis off NW Patagonia

2020 ◽  
Vol 77 (5) ◽  
pp. 1927-1940
Author(s):  
Pamela Toledo ◽  
Edwin J Niklitschek ◽  
Audrey M Darnaude ◽  
Félix P Leiva ◽  
Chris Harrod ◽  
...  
Keyword(s):  
Life Cycle ◽  
Habitat Use ◽  
Diet Composition ◽  
Trophic Ecology ◽  
Trophic Position ◽  
Life Cycles ◽  
Partial Migration ◽  
Otolith Chemistry ◽  
Management Approaches ◽  
Isotope Analyses

Abstract Partial migration, where migrant and resident organisms coexist within the same population, has been found in many fishes. Although it seems obvious that different life cycles exploit habitats and food webs differently, few assessments about the trophic consequences of partial migration are available. To unveil part of this complexity, we combined otolith chemistry with stable isotope analyses data for hind-casting Merluccius australis habitat use and diet composition at age. By providing detailed information about lifetime variability in diet, trophic position, and prey demand of four M. australis life-cycle types, we show that these groups feed differentially in estuarine and oceanic habitats throughout their ontogeny. Although trophic positions were similar between habitats for juvenile and subadults, substantial differences between life-cycle types were found regarding lifetime diet and trophic demand. Thus, the more abundant and heavily exploited oceanic stock of M. australis was heavily dependent of estuarine habitats within the Patagonian Fjords System, where it consumes large biomasses of Macruronus magellanicus, Pasiphaea, Sprattus fuegensis, and Euphausiidae at earlier stages. We show ignoring trophic consequences of partial migration and life-cycle diversity may produce highly biased results, both in terms of prey and habitat use, which appears critical for multispecies and ecosystem management approaches.

scholarly journals Trophic position derived from amino-acid nitrogen isotopes reflect physiological status of both predator and prey over four decades

2021 ◽  
Author(s):  
Agnes ML Karlson ◽  
Caroline Ek ◽  
Douglas Jones
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Baltic Sea ◽  
Food Webs ◽  
Trophic Ecology ◽  
Trophic Position ◽  
Physiological Status ◽  
Ecological Knowledge ◽  
Ecological Data ◽  
Isotope Analyses

AbstractNitrogen isotope analyses of amino-acids (δ15N-AA) are increasingly used to decipher food webs. Interpretation of δ15N-AA in consumers relies on the assumption that physiological status has a negligible influence on the trophic enrichment factor (TEF). Recent experiments have shown that this is not always the case and there is a need to validate derived trophic position (TP) estimates using ecological data. We analyzed δ15N-AA in cod and herring (1980-2019) from the Baltic Sea, a species-poor system where dramatic reduction in condition status of cod has occurred. We expected that TEFcod-herring in trophic AAs would increase during periods of poor cod growth, resulting in inflated TP estimates. We found that TEF and TP estimates were negatively linked to individual condition status, prey fat content and the hypoxic state of the ecosystem. Statistically adjusting for these variables resulted in lower cod TP, highlighting the importance of including ecological knowledge when interpreting TP.Scientific Significance StatementNitrogen stable isotope analyses in amino acids are increasingly used in ecology to understand how environmental change impacts food-webs. Specifically, it is used to more accurately calculate trophic position (TP) of consumers. Controlled experiments have shown that physiological status can alter amino acid isotope composition and TP interpretation, but field studies are lacking. We use 40 years of archived material to demonstrate that TP estimates in Baltic Sea cod and its prey herring are directly related to physiological status. This has important implications for interpreting the real trophic ecology of consumers under environmental stress. By simultaneously measuring condition status in both predator and prey it is possible to adjust for them as confounding variables and decipher actual consumer TP.

Stable isotope analyses reveal individual variability in the trophic ecology of a top marine predator, the southern elephant seal

Oecologia ◽  
2011 ◽  
Vol 169 (2) ◽  
pp. 395-406 ◽  
Author(s):  
L. A. Hückstädt ◽  
P. L. Koch ◽  
B. I. McDonald ◽  
M. E. Goebel ◽  
D. E. Crocker ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Trophic Ecology ◽  
Elephant Seal ◽  
Individual Variability ◽  
Southern Elephant Seal ◽  
Stable Isotope Analyses ◽  
Marine Predator ◽  
Isotope Analyses
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