scholarly journals Variability in copepod trophic levels and in feeding selectivity based on stable isotope analysis in Gwangyang Bay off the southern coast of Korea

2017 ◽  
Author(s):  
Mianrun Chen ◽  
Dongyoung Kim ◽  
Hongbin Liu ◽  
Chang-Keun Kang
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Salinity Gradient ◽  
Isotope Analysis ◽  
Trophic Levels ◽  
Food Sources ◽  
Linear Regression Models ◽  
Model Calculations ◽  
Δ13c And Δ15n ◽  
Gwangyang Bay

Abstract. Trophism (i.e., food resources and trophic levels) of different copepod groups was assessed along a salinity gradient in the temperate estuarine Gwangyang Bay of Korea, based on seasonal investigation of taxonomic results in 2015 and stable isotope analysis incorporating multiple linear regression models. The δ13C and δ15N values of copepods in the bay displayed salinity-associated spatial heterogeneity as well as temperature-related seasonal variations. Both spatial and temporal variations reflected those in isotopic values of food sources. Three major groups (marine calanoids, brackish water calanoids and cyclopoids) had a mean trophic level of 2.2 relative to nanoplankton as the basal food source, similar to the bulk copepod assemblage; however, they had dissimilar food sources based on the different δ13C values. Calanoid isotopic values indicated a mixture of different genera including species with high δ15N values (e.g., Sinocalanus and Labidocera) and relatively low δ15N values (Paracalanus and Acartia). Feeding preferences of different copepods probably explain these seasonal and spatial patterns of the community trophic niche. Bayesian mixing model calculations based on source materials of two size fractions of particulate organic matter (nanoplankton at

scholarly journals Variability in copepod trophic levels and feeding selectivity based on stable isotope analysis in Gwangyang Bay of the southern coast of the Korean Peninsula

2018 ◽  
Vol 15 (7) ◽  
pp. 2055-2073 ◽  
Author(s):  
Mianrun Chen ◽  
Dongyoung Kim ◽  
Hongbin Liu ◽  
Chang-Keun Kang
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Salinity Gradient ◽  
Isotope Analysis ◽  
Trophic Levels ◽  
Food Sources ◽  
Primary Producers ◽  
Model Calculations ◽  
Δ13c And Δ15n ◽  
Gwangyang Bay

Abstract. Trophic preference (i.e., food resources and trophic levels) of different copepod groups was assessed along a salinity gradient in the temperate estuarine Gwangyang Bay of Korea, based on seasonal investigation of taxonomic results in 2015 and stable isotope analysis incorporating multiple linear regression models. The δ13C and δ15N values of copepods in the bay displayed significant spatial heterogeneity as well as seasonal variations, which were indicated by their significant relationships with salinity and temperature, respectively. Both spatial and temporal variations reflected those in isotopic values of food sources. The major calanoid groups (marine calanoids and brackish water calanoids) had a mean trophic level of 2.2 relative to nanoplankton as the basal food source, similar to the bulk copepod assemblage; however, they had dissimilar food sources based on the different δ13C values. Calanoid isotopic values indicated a mixture of different genera including species with high δ15N values (e.g., Labidocera, Sinocalanus, and Tortanus), moderate values (Calanus sinicus, Centropages, Paracalanus, and Acartia), and relatively low δ15N values (Eurytemora pacifica and Pseudodiaptomus). Feeding preferences of different copepods probably explain these seasonal and spatial patterns of the community trophic niche. Bayesian mixing model calculations based on source materials of two size fractions of particulate organic matter (nanoplankton at < 20 µm vs. microplankton at 20–200 µm) indicated that Acartia and Centropages preferred large particles; Paracalanus, Calanus, Eurytemora, and Pseudodiaptomus apparently preferred small particles. Tortanus was typically carnivorous with low selectivity on different copepods. Labidocera preferred marine calanoids Acartia, Centropages, and harpacticoids; on the other hand, Sinocalanus and Corycaeus preferred brackish calanoids Paracalanus and Pseudodiaptomus. Overall, our results depict a simple energy flow of the planktonic food web of Gwangyang Bay: from primary producers (nanoplankton) and a mixture of primary producers and herbivores (microplankton) through omnivores (Acartia, Calanus, Centropages, and Paracalanus) and detritivores (Pseudodiaptomus, Eurytemora, and harpacticoids) to carnivores (Corycaeus, Tortanus, Labidocera, and Sinocalanus).

Stable isotope analysis reveals partitioning in prey use by Kajikia audax (Istiophoridae), Thunnus albacares, Katsuwonus pelamis, and Auxis spp. (Scombridae) in the Eastern Tropical Pacific of Ecuador

2021 ◽  
Vol 19 (4) ◽  
Author(s):  
Rigoberto Rosas-Luis ◽  
Nancy Cabanillas-Terán ◽  
Carmen A. Villegas-Sánchez
Keyword(s):  
Stable Isotope ◽  
Food Web ◽  
Stable Isotope Analysis ◽  
Trophic Ecology ◽  
Isotope Analysis ◽  
Middle Level ◽  
Food Sources ◽  
Thunnus Albacares ◽  
Katsuwonus Pelamis ◽  
Δ13c And Δ15n

Abstract Kajikia audax, Thunnus albacares, Katsuwonus pelamis, and Auxis spp. occupy high and middle-level trophic positions in the food web. They represent important sources for fisheries in Ecuador. Despite their ecological and economic importance, studies on pelagic species in Ecuador are scarce. This study uses stable isotope analysis to assess the trophic ecology of these species, and to determine the contribution of prey to the predator tissue. Isotope data was used to test the hypothesis that medium-sized pelagic fish species have higher δ15N values than those of the prey they consumed, and that there is no overlap between their δ13C and δ15N values. Results showed higher δ15N values for K. audax, followed by T. albacares, Auxis spp. and K. pelamis, which indicates that the highest position in this food web is occupied by K. audax. The stable isotope Bayesian ellipses demonstrated that on a long time-scale, these species do not compete for food sources. Moreover, δ15N values were different between species and they decreased with a decrease in predator size.

Dual stable isotope analysis (δ13C and δ15N) of soil invertebrates and their food sources

Pedobiologia ◽  
2004 ◽  
Vol 48 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Olaf Schmidt ◽  
James P Curry ◽  
Jens Dyckmans ◽  
Emilia Rota ◽  
Charles M Scrimgeour
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Soil Invertebrates ◽  
Food Sources ◽  
Δ13c And Δ15n

Food sources for the bivalve Corbicula japonica in the foremost fishing lakes estimated from stable isotope analysis

2006 ◽  
Vol 72 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Akihide KASAI ◽  
Haruhiko TOYOHARA ◽  
Akiko NAKATA ◽  
Tsunehiro MIURA ◽  
Nobuyuki AZUMA
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Food Sources ◽  
Corbicula Japonica

Food sources of the pearl oyster in coastal ecosystems of Japan: Evidence from diet and stable isotope analysis

2008 ◽  
Vol 76 (3) ◽  
pp. 704-709 ◽  
Author(s):  
Kayoko Fukumori ◽  
Misa Oi ◽  
Hideyuki Doi ◽  
Noboru Okuda ◽  
Hitomi Yamaguchi ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Pearl Oyster ◽  
Coastal Ecosystems ◽  
Food Sources

scholarly journals Morphology and stable isotope analysis demonstrate different structuring of bat communities in rainforest and savannah habitats

2018 ◽  
Vol 5 (12) ◽  
pp. 180849 ◽  
Author(s):  
Ara Monadjem ◽  
Adam Kane ◽  
Peter Taylor ◽  
Leigh R. Richards ◽  
Grant Hall ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Niche Breadth ◽  
Isotope Analysis ◽  
Morphological Characters ◽  
Trophic Levels ◽  
Species Packing ◽  
Dietary Niche ◽  
The One ◽  
Ellipse Area

Bats play important ecological roles in tropical systems, yet how these communities are structured is still poorly understood. Our study explores the structure of African bat communities using morphological characters to define the morphospace occupied by these bats and stable isotope analysis to define their dietary niche breadth. We compared two communities, one in rainforest (Liberia) and one in savannah (South Africa), and asked whether the greater richness in the rainforest was due to more species ‘packing’ into the same morphospace and trophic space than bats from the savannah, or some other arrangement. In the rainforest, bats occupied a larger area in morphospace and species packing was higher than in the savannah; although this difference disappeared when comparing insectivorous bats only. There were also differences in morphospace occupied by different foraging groups (aerial, edge, clutter and fruitbat). Stable isotope analysis revealed that the range of δ 13 C values was almost double in rainforest than in savannah indicating a greater range of utilization of basal C 3 and C 4 resources in the former site, covering primary productivity from both these sources. The ranges in δ 15 N, however, were similar between the two habitats suggesting a similar number of trophic levels. Niche breadth, as defined by either standard ellipse area or convex hull, was greater for the bat community in rainforest than in savannah, with all four foraging groups having larger niche breadths in the former than the latter. The higher inter-species morphospace and niche breadth in forest bats suggest that species packing is not necessarily competitive. By employing morphometrics and stable isotope analysis, we have shown that the rainforest bat community packs more species in morphospace and uses a larger niche breadth than the one in savannah.

Habitat, trophic levels and migration patterns of the short-finned squid Illex argentinus from stable isotope analysis of beak regions

Polar Biology ◽  
2019 ◽  
Vol 42 (12) ◽  
pp. 2299-2304 ◽  
Author(s):  
José P. Queirós ◽  
Richard A. Phillips ◽  
Alexandra Baeta ◽  
José Abreu ◽  
José C. Xavier
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Trophic Levels ◽  
Migration Patterns ◽  
Illex Argentinus ◽  
And Migration

Trophic relationships of the platypus: insights from stable isotope and cheek pouch dietary analyses

2016 ◽  
Vol 67 (8) ◽  
pp. 1196 ◽  
Author(s):  
Melissa Klamt ◽  
Jenny A. Davis ◽  
Ross M. Thompson ◽  
Richard Marchant ◽  
Tom R. Grant
Keyword(s):  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Trophic Relationships ◽  
Cheek Pouch ◽  
Insect Larvae ◽  
Top Down ◽  
Δ13c And Δ15n ◽  
Eastern Australia ◽  
Wide Range

The unique Australian monotreme, the platypus (Ornithorhynchus anatinus) potentially exerts a strong top-down influence on riverine food webs in eastern Australia. However, despite considerable interest in the evolutionary history and physiology of the platypus, little is known of its trophic relationships. To address this lack of knowledge we used stable isotope analysis, in combination with the analysis of food items stored in cheek pouches, to determine its position in a typical riverine food web. This was the essential first step in the process of designing a larger study to investigate the relative importance of top-down and bottom-up effects in rivers where the platypus occurs. We found that platypuses were feeding on a wide range of benthic invertebrates, particularly insect larvae. The similarity of δ13C and δ15N values recorded for the platypus, a native fish (Galaxias sp.) and the exotic mosquitofish (Gambusia holbrooki) indicated dietary overlap and potential competition for the same resources. Although cheek pouch studies identify most of the major groups of prey organisms, the potential for contribution of the soft-bodied organisms such as larval dipterans, is suggested by stable isotope analysis, indicating that the use of both techniques will be important in future ecological investigations.

Trophic ecology of the blue shark (Prionace glauca) based on stable isotopes (δ13C and δ15N) and stomach content

2015 ◽  
Vol 96 (7) ◽  
pp. 1403-1410 ◽  
Author(s):  
Sandra Berenice Hernández-Aguilar ◽  
Ofelia Escobar-Sánchez ◽  
Felipe Galván-Magaña ◽  
Leonardo Andrés Abitia-Cárdenas
Keyword(s):  
Stable Isotope ◽  
Stomach Content ◽  
Trophic Ecology ◽  
Baja California ◽  
Marine Ecosystem ◽  
Isotope Analysis ◽  
Trophic Levels ◽  
Baja California Sur ◽  
Δ13c And Δ15n ◽  
Prionace Glauca

Occupying the upper levels of trophic webs and thus regulating prey at lower levels, sharks play an important role in the trophic structure and energy dynamics of marine ecosystems. In recent years, the removal of these individuals from upper trophic levels as a result of overfishing has negatively affected ecosystems. We analysed the diet of blue sharks (Prionace glauca) caught off the west coast of Baja California Sur, Mexico, during the months of February–June in 2001, 2005 and 2006. We employed both stomach content and stable isotope analyses as each method provides distinct yet important information regarding the role of blue sharks in marine food webs, allowing us to estimate the relative contribution of different prey items to this predator's diet. Of the 368 stomachs analysed, 210 contained food (57%) and 158 (43%) were empty. Based on stomach contents and the index of relative importance (IRI), the pelagic red crab (Pleuroncodes planipes) was the most important prey, followed by the squids Gonatus californiensis (34.1%) and Ancistrocheirus lesueurii (10.4%). The mean (±SD) values for δ15N (16.48 ± 0.94‰) and δ13C (−18.48 ± 0.63‰) suggest that blue sharks prefer feeding in oceanic waters. The trophic level based on stomach content analysis was 4.05, while that based on the stable isotope analysis was 3.8, making blue sharks top consumers in the marine ecosystem of Baja California Sur, Mexico.

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