Stable isotopes in jumbo squid (Dosidicus gigas) beaks to estimate its trophic position: comparison between stomach contents and stable isotopes

2006 ◽  
Vol 86 (2) ◽  
pp. 437-445 ◽  
Author(s):  
R.I. Ruiz-Cooley ◽  
Unai Markaida ◽  
D. Gendron ◽  
S. Aguíñiga
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Trophic Position ◽  
Stomach Contents ◽  
Isotope Ratios ◽  
Trophic Relationships ◽  
Dosidicus Gigas ◽  
Jumbo Squid ◽  
C And N ◽  
Biomass Increase

Stomach contents and carbon (C) and nitrogen (N) stable isotope analysis were used to evaluate trophic relationships of jumbo squid, Dosidicus gigas. Buccal masses, beaks and stomach contents of large and medium maturing-sized jumbo squid and muscle from its main prey, the myctophid Benthosema panamense, were collected in the Gulf of California, Mexico during 1996, 1997 and 1999. Both the quantified C and N-isotope ratios in muscle, and stomach content analysis revealed that larger-sized maturing squid showed a higher trophic position than medium-sized individuals. However, a discrepancy between stomach contents versus stable isotope analyses was found in evaluating trophic relationships. Simple dilution models as a function of growth were used to estimate the C and N renewal dietary shift for jumbo squid. Estimates of the initial C and N pools in D. gigas with an initial age of 70 days and 210 days indicated isotopic shifts of 32% after a threefold biomass increase and 25% after a fourfold biomass increase, respectively. Additionally, beak samples of jumbo squid were evaluated as an alternative tissue to estimate squid trophic position using stable isotopes. The results showed a significant correlation between stable isotope ratios from muscle and beak samples. Muscle isotope values were higher than beak by 1% and 4% for δ13C and δ15N respectively. A test with jumbo squid beaks collected from a stomach of a stranded sperm whale confirmed the viability of this method.

scholarly journals Trophic relationships between sperm whales and jumbo squid using stable isotopes of C and N

2004 ◽  
Vol 277 ◽  
pp. 275-283 ◽  
Author(s):  
RI Ruiz-Cooley ◽  
D Gendron ◽  
S Aguíñiga ◽  
S Mesnick ◽  
JD Carriquiry
Keyword(s):  
Stable Isotopes ◽  
Trophic Relationships ◽  
Sperm Whales ◽  
Jumbo Squid ◽  
C And N

From diet to hair and blood: empirical estimation of discrimination factors for C and N stable isotopes in five terrestrial mammals

2020 ◽  
Vol 101 (5) ◽  
pp. 1332-1344
Author(s):  
Ève Rioux ◽  
Fanie Pelletier ◽  
Martin-Hugues St-Laurent
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Diet Composition ◽  
Black Bear ◽  
Isotope Ratios ◽  
Trophic Relationships ◽  
Stable Isotope Ratios ◽  
Mammal Species ◽  
Carbon And Nitrogen ◽  
Discrimination Factors

Abstract Carbon and nitrogen stable isotope ratios are used widely to describe wildlife animal diet composition and trophic interactions. To reconstruct consumer diet, the isotopic differences between consumers and their diet items—called the trophic discrimination factor (TDF)—must be known. Proxies of diet composition are sensitive to the accuracy of TDFs. However, specific TDFs are still missing for many species and tissues because only a few controlled studies have been carried out on captive animals. The aim of this study was to estimate TDFs for hair and blood for carbon and nitrogen stable isotopes for caribou, moose, white-tailed deer, eastern coyote, and black bear. We obtained stable isotope ratios for diet items, hair, and blood samples, of 21 captive adult mammals. Diet–tissue discrimination factors for carbon in hair (∆ 13CLE) ranged from 0.96‰ to 3.72‰ for cervids, 3.01‰ to 3.76‰ for coyote, and 5.15‰ to 6.35‰ for black bear, while nitrogen discrimination factors (∆ 15N) ranged from 2.58‰ to 5.95‰ for cervids, 2.90‰ to 3.13‰ for coyote, and 4.48‰ to 5.44‰ for black bear. The ∆ 13CLE values in coyote blood components ranged from 2.20‰ to 2.69‰ while ∆ 15N ranged from 3.30‰ to 4.41‰. In caribou serum, ∆ 13CLE reached 3.34 ± 1.28‰ while ∆ 15N reached 5.02 ± 0.07‰. The TDFs calculated in this study will allow the evaluation of diet composition and trophic relationships between these five mammal species and will have important implications for the study of endangered caribou populations for which the use of noninvasive tissue sampling is highly relevant.

A trophic study of a marine ecosystem off southeastern Australia using stable isotopes of carbon and nitrogen

2002 ◽  
Vol 59 (3) ◽  
pp. 514-530 ◽  
Author(s):  
Stephanie R Davenport ◽  
Nicholas J Bax
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Marine Mammals ◽  
Marine Ecosystem ◽  
Stomach Contents ◽  
Trophic Relationships ◽  
Carbon And Nitrogen ◽  
Southeastern Australia ◽  
Functional Patterns ◽  
Bottom Depth

The stable isotopes of carbon and nitrogen were used to investigate trophic relationships of fish and invertebrates on the continental shelf of southeastern Australia. We examined 87 fish species, marine mammals, penguins, invertebrates, algal samples, suspended particulate organic matter (POM), and sediments. The main source of primary production is oceanic phytoplankton, although there is evidence of a seagrass contribution to the benthos. Marine mammals, penguins, some benthic invertebrates, and some benthic fish filled the highest trophic positions. Sources of variability in isotope results included temporal (POM, some fish) and spatial (POM, sediments) elements, bottom depth (some fish), and size (some fish). Fish had muscle δ15N values of 9.6‰ to 14.7‰ and δ13C values of –20.6‰ to –14.6‰. Cluster analysis on fish stable isotope results produced fish groups that could be interpreted with trophic and habitat information. Trophic relationships in fish, suggested by stable isotope results, were supported by stomach contents analysis. Stable isotope results may indicate more representative trophic relationships, as stomach contents analyses tend to group prey by taxon rather than by trophodynamic position. In fish and invertebrates, stable isotope results related more to functional patterns of feeding than to taxonomic relationships.

scholarly journals Feeding habits and population aspects of the spotted goatfish, Pseudupeneus maculatus (Perciformes: Mullidae), on the continental shelf of northeast Brazil

2020 ◽  
Vol 84 (2) ◽  
Author(s):  
Andrey Soares ◽  
Alex Souza Lira ◽  
Júlio Guazzelli Gonzalez ◽  
Leandro Nolé Eduardo ◽  
Flávia Lucena-Frédou ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Continental Shelf ◽  
Trophic Position ◽  
Feeding Habits ◽  
Stomach Contents ◽  
Distribution Patterns ◽  
Isotope Ratios ◽  
Stomach Content Analysis ◽  
Stable Isotope Ratios ◽  
Weight Percentage

This study provides information about the feeding habits, population aspects and spatial distribution of the spot­ted goatfish, Pseudupeneus maculatus, along the coast of the tropical Brazilian continental shelf. Distribution patterns are described using length frequencies and catch rates. Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N), along with stomach contents, were analysed to determine the diet of the spotted goatfish. Multivariate analysis and numerical indicators of the diet, such as numerical frequency, frequency of occurrence and weight percentage, were computed to evaluate the diet composition. The mean trophic position was defined using both stable isotope ratios and stomach content analysis. The length at first maturity for the species was determined as 13.7 cm. A slight pattern in size distribution was observed, with mean size increasing with depth along the shelf. The diet was mainly composed of crustaceans, teleosts and Polychaeta. No clear dietary difference was found between habitat types, water depth or latitude. Both trophic positions estimated by stable isotopes and stomach contents analysis ranged between levels 3 and 4. P. Maculatus was found to be feeding on many rare and infrequent prey items, classifying it as a generalist zoobenthivorous predator, probably due to its efficient search strategy.

scholarly journals Assessment of trophic relationships between symbiotic tropical ophiuroids using C and N stable isotope analysis

2006 ◽  
Vol 86 (6) ◽  
pp. 1443-1447 ◽  
Author(s):  
D. Fourgon ◽  
G. Lepoint ◽  
I. Eeckhaut
Keyword(s):  
Stable Isotopes ◽  
Potential Benefit ◽  
Feeding Habits ◽  
Isotope Analysis ◽  
Tracer Experiment ◽  
Trophic Relationships ◽  
Nitrogen Stable Isotopes ◽  
Carbon And Nitrogen ◽  
C And N ◽  
The One

Analyses of the natural abundance of carbon and nitrogen stable isotopes were performed to investigate the feeding habits of two ophiuroids, Ophiomastix venosa and Ophiocoma scolopendrina, and to assess the potential benefit obtained by the symbiotic Ophiomastix venosa juveniles. A tracer experiment was also carried out to clarify the contribution of algae to the nitrogen uptake amongst the tested ophiuroids. Our results suggest that Ophiocoma scolopendrina adults occupy a higher position in the food web than Ophiomastix venosa and mainly feed on neuston. In contrast, O. venosa adults feed on the alga Sargassum densifolium and on organic matter associated with sediment. Free juveniles and symbiotic juveniles of O. venosa have intermediate δ13C values between both adult species. The high proportion of 13C in the symbiotic juveniles compared to the one in their conspecific adults indicates that their diet slightly differs from the latter and is closer to that of Ophiocoma scolopendrina. This raises the hypothesis that symbiotic juveniles steal neuston from their associated host, O. scolopendrina.

Long-term variation in isotopic baselines and implications for estimating consumer trophic niches

2008 ◽  
Vol 65 (10) ◽  
pp. 2191-2200 ◽  
Author(s):  
Christopher T. Solomon ◽  
Stephen R. Carpenter ◽  
James A. Rusak ◽  
M. Jake Vander Zanden
Keyword(s):  
Stable Isotope ◽  
Food Web ◽  
Isotope Ratios ◽  
Trophic Niche ◽  
Accurate Estimation ◽  
Stable Isotope Ratios ◽  
Turnover Rates ◽  
C And N ◽  
Trophic Niches

Carbon and nitrogen stable isotope ratios are increasingly used to study long-term food web change. Temporal variation at the base of the food web may impact the accuracy of trophic niche estimates, but data describing interannual baseline variation are limited. We quantified baseline variation over a 23-year period in a north-temperate lake and used a simulation model to examine how this variation might affect consumer trophic niche estimates. Interannual variation in C and N stable isotope ratios was significant for both benthic and pelagic primary consumer baselines. Long-term linear trends and shorter-term autoregressive patterns were apparent in the data. There were no correlations among benthic and pelagic C and N baselines. Simulations demonstrated that error in estimated fish trophic niches, but not bias, increased substantially when sampling of baselines was incomplete. Accurate trophic niche estimates depended more on accurate estimation of baseline time series than on accurate estimation of growth and turnover rates. These results highlight the importance of previous and continued efforts to constrain bias and error in long-term stable isotope food web studies.

Spatial and trophic preferences of jumbo squid Dosidicus gigas (D'Orbigny, 1835) in the central Gulf of California: ecological inferences using stable isotopes

2018 ◽  
Vol 32 (15) ◽  
pp. 1225-1236 ◽  
Author(s):  
L.D. Trasviña-Carrillo ◽  
A. Hernández-Herrera ◽  
Y.E. Torres-Rojas ◽  
F. Galván-Magaña ◽  
A. Sánchez-González ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Gulf Of California ◽  
Dosidicus Gigas ◽  
Jumbo Squid ◽  
Trophic Preferences
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