Food spectrum and trophic position of an Arctic cephalopod, Rossia palpebrosa (Sepiolida), inferred by stomach contents and stable isotope (δ13C and δ15N) analyses

2019 ◽  
Vol 632 ◽  
pp. 131-144 ◽  
Author(s):  
AV Golikov ◽  
FR Ceia ◽  
RM Sabirov ◽  
AN Belyaev ◽  
ME Blicher ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Trophic Position ◽  
Stomach Contents ◽  
Food Spectrum ◽  
Δ13c And Δ15n

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.

Diet reveals potential for competition and coexistence among coyotes (Canis latrans), red foxes (Vulpes vulpes), and gray foxes (Urocyon cinereoargenteus)

2021 ◽  
Author(s):  
Henry Masters ◽  
Christine R Maher
Keyword(s):  
Vulpes Vulpes ◽  
Canis Latrans ◽  
Trophic Position ◽  
Stomach Contents ◽  
Isotopic Niche ◽  
Early Winter ◽  
Urocyon Cinereoargenteus ◽  
Red Foxes ◽  
Δ13c And Δ15n ◽  
Hair Samples

Species can alleviate competition by reducing diet overlap. Nonnative coyotes (Canis latrans (Say, 1823)) and historically native gray foxes (Urocyon cinereoargenteus (Schreber, 1775)) have expanded their ranges and may compete with native red foxes (Vulpes vulpes (Linnaeus, 1758)). To examine potential competition among canids in Maine, we compared δ13C and δ15N from muscle and hair samples to assess relative resource use, and we compared frequency of occurrence of prey items from stomach contents to assess diets. For these species, red foxes consumed anthropogenically-based foods the most in fall-early winter, gray foxes consumed anthropogenically-based foods the most in summer, and coyotes consumed anthropogenically-based foods the least in all seasons. Coyotes held the highest relative trophic position in fall-early winter, red foxes held the highest relative trophic position in summer, and gray foxes held the lowest relative trophic position. Based on stomach contents, gray foxes had the broadest diet and consumed the most plants, and coyotes had the narrowest diet. Red foxes were the only species to show isotopic niche overlap with both potential competitors across seasons. Thus they may be most susceptible to competitive exclusion among these canids, with implications for community dynamics as ranges shift due to human activity.

scholarly journals Manta birostris , predator of the deep? Insight into the diet of the giant manta ray through stable isotope analysis

2016 ◽  
Vol 3 (11) ◽  
pp. 160717 ◽  
Author(s):  
Katherine B. Burgess ◽  
Lydie I. E. Couturier ◽  
Andrea D. Marshall ◽  
Anthony J. Richardson ◽  
Scarla J. Weeks ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Large Scale ◽  
Trophic Position ◽  
Isotope Analysis ◽  
Stomach Contents ◽  
Foraging Strategies ◽  
Manta Birostris ◽  
Elusive Species ◽  
Manta Ray

The characterization of diet for the giant manta ray Manta birostris has been problematic given their large-scale movement patterns and the difficulty in obtaining stomach contents from this species. The large majority of existing information is based on observational data limited to feeding events at the sea surface during daylight. Recently discovered aggregation sites for the giant manta ray off mainland Ecuador are some of the most accessible to date and provide a unique opportunity for researchers to gather much needed information on this elusive species. To assess how important surface zooplankton is to giant manta ray diet, we conducted stable isotope analysis ( 15 N and 13 C) on M. birostris muscle and surface zooplankton. Trophic position estimates placed M. birostris overall at a secondary consumer level of approximately 3.4 but there was large variation in δ 15 N and δ 13 C values among individuals. Manta birostris muscle tissue δ 13 C values were also not consistent with this species feeding predominantly on surface zooplankton and suggest that the majority of dietary intake is of mesopelagic origin. Given the conservative life history and fisheries pressure on large planktivores, knowledge of their trophic role and foraging strategies is essential to better understand their ecology and develop effective conservation measures.

scholarly journals Using Stable Carbon and Nitrogen Isotopes to Evaluate Parrotfish Diet

2013 ◽  
pp. 108-123
Author(s):  
Maria Elisa Gerona ◽  
Florence Evacitas
Keyword(s):  
Stable Isotope ◽  
Nitrogen Isotopes ◽  
Trophic Position ◽  
Isotope Analysis ◽  
Carbon Sources ◽  
Δ13c And Δ15n ◽  
Δ13c Values ◽  
Dual Isotope ◽  
Muscle Tissues ◽  
Carbon Intake

With limited inconclusive data provided by gut content analysis, stable isotope analysis has recently emerged to validate trophic position and dietary intake. In this study, a dual isotope approach was used to reveal parrotfish feeding. Comparisons of δ13C and δ15N values of muscle and liver among yellow barred (Scarus dimidiatus), rosy cheek (S. psittacus), and blue-barred (S. ghobban) parrotfishes from Canigao Island, Matalom, Leyte were made to track dietary shifting and to compare dietary carbon intake. Trophic assignment was based on the assumption that consumers are enriched by a factor of 3-4‰ for δ15N, relative to their diet. The δ13C values of muscle tissues of the three species of parrotfish were significantly higher (p=0.001) than those of their liver suggesting dietary shifting. The δ13C values of both muscle and liver tissues of S. dimidiatus were significantly (p<0.001) higher than those of S. psittacus and S. ghobban, but δ13C values of muscle and liver of S. psittacus and S. ghobban did not vary significantly. These mean that S. dimidiatus have different long term and recent dietary carbon intake compared to the other two species, while S. psittacus and S. ghobban have relatively the same dietary carbon intake. Considering the 1‰ δ13C trophic enrichment of consumers relative to their diet, possible dietary carbon sources of the sampled parrotfish include Dendronephthya spp., Ulva reticulata, Sargassum oligocystum, Dictyota sp., Digenea sp., Chlorodesmis sp., and Sargassum muticum suggesting that parrotfishes are generalist consumers. Mean stable isotope nitrogen ratios of S. dimidiatus (5.9‰), S. psittacus (6.9‰) and S. ghobban (6.7‰) together with their carbon isotope ratios confirmed that all sampled parrotfish species are generalist primary consumers.

scholarly journals Predicting trophic position in sharks of the north-west Atlantic Ocean using stable isotope analysis

2003 ◽  
Vol 83 (6) ◽  
pp. 1347-1350 ◽  
Author(s):  
James A. Estrada ◽  
Aaron N. Rice ◽  
Molly E. Lutcavage ◽  
Gregory B. Skomal
Keyword(s):  
Stable Isotope ◽  
Trophic Position ◽  
Isotope Analysis ◽  
Stomach Contents ◽  
North West ◽  
The North ◽  
Shortfin Mako ◽  
Thresher Shark ◽  
Basking Shark ◽  
Thresher Sharks

Trophic positions (TP) were estimated for the blue shark (Prionace glauca), shortfin mako (Isurus oxyrinchus), thresher shark (Alopias vulpinus), and basking shark (Cetorhinus maximus) using stable isotope ratios of carbon (δ13C) and nitrogen (δ15N). The basking shark had the lowest TP (3·1) and δ15N value (10·4‰), whereas the thresher shark had the highest values (4·5, 15·2‰). Mako sharks showed considerable variation in TP and isotopic values, possibly due to foraging from both inshore and offshore waters. Thresher sharks were significantly more enriched in δ15N than blue sharks and mako sharks, suggesting a different prey base. The δ13C values of thresher sharks and mako sharks varied significantly, but neither was significantly different from that of blue sharks. No statistical differences were found between our TP estimations and those derived from published stomach contents analyses, indicating that stable isotope data may be used to estimate the trophic status of sharks.

scholarly journals Symbiotic relationship between the carapid fish Onuxodon fowleri (Ophidiiformes: Carapidae) and the pearl oyster Pinctada margaritifera (Mollusca: Bivalvia: Pteriidae)

2018 ◽  
Vol 82 (1) ◽  
pp. 35
Author(s):  
Orphal Colleye ◽  
Loïc Kéver ◽  
Gilles Lepoint ◽  
David Lecchini ◽  
Eric Parmentier
Keyword(s):  
Stable Isotope ◽  
Stomach Contents ◽  
French Polynesia ◽  
Pearl Oyster ◽  
Food Sources ◽  
Exact Nature ◽  
Δ13c And Δ15n ◽  
Pinctada Margaritifera ◽  
New Information ◽  
Study Support

At Makemo Atoll (French Polynesia), the carapid fish Onuxodon fowleri lives in symbiosis with the black-lip pearl oyster Pinctada margaritifera. Although the symbiont seems to live inside its host bivalve by using it as a shelter, additional data are still needed to better understand the exact nature of this association. For this purpose, we implemented an approach using stable isotope ratios of carbon (13C/12C) and nitrogen (15N/14N). The δ13C and δ15N values were measured in tissues of the pearl oyster (gonads, gills, mantle and muscles), white muscle tissue from the fish and other food sources. This stable isotope approach was also complemented by the analysis of stomach contents in the carapid fish. Overall, the isotopic compositions measured in the present study support a commensal relationship between O. fowleri and P. margaritifera. In addition, our isotopic data bring new information about another guest living inside P. margaritifera, namely the palaemonid shrimp Conchodytes meleagrinae. Based on the δ13C and δ15N values, it appears that the shrimp might feed on the bivalve gonads.

Isotopic evidence for size-based dietary shifts in the jellyfish Cyanea nozakii in the northern East China Sea

2020 ◽  
Author(s):  
Pengpeng Wang ◽  
Fang Zhang ◽  
Mengtan Liu ◽  
Song Sun ◽  
Haochen Xian
Keyword(s):  
Stable Isotope ◽  
East China Sea ◽  
Trophic Position ◽  
Food Sources ◽  
East China ◽  
Δ13c And Δ15n ◽  
Dietary Shift ◽  
China Sea ◽  
Important Food Source ◽  
Dietary Shifts

Abstract Cyanea nozakii is a common bloom-forming Scyphomedusa in coastal waters of China. To understand the diet of this jellyfish and its trophic relationship with other zooplankton groups, stable isotope δ13C and δ15N values of C. nozakii in the bloom area within the northern East China Sea (ECS) in August 2017 were analyzed. We examined: first, the size-based variation in C. nozakii stable isotope values, second, the contributions of different food sources to the C. nozakii diet, and possible size-based dietary shifts in individual C. nozakii and, third, the contribution of gelatinous prey to the C. nozakii diet. Isotope values of differently sized C. nozakii ranged from −18.81 to −16.88‰ for δ13C and from 8.23 to 10.46‰ for δ15N. A significant change in δ15N values implies that the trophic position and the diet of C. nozakii changed as body size increased. The MixSIAR model indicated that C. nozakii underwent a dietary shift during growth, from a seston-dominant diet in smaller medusae to a zooplankton-dominant diet in larger medusae. Copepods were an important food source for C. nozakii, irrespective of size. The mean proportions of gelatinous zooplankton increased significantly in the C. nozakii diet with increasing C. nozakii diameter, suggesting that larger C. nozakii consumed more gelatinous prey. The diet of larger C. nozakii included 9.54% Nemopilema nomurai and 9.53% small medusae. The results suggest that intraguild predation among these jellyfish exist in the northern ECS.

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.

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.

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