scholarly journals Trophic interactions between two neustonic organisms: insights from Bayesian stable isotope data analysis tools

2020 ◽  
Vol 146 (2) ◽  
Author(s):  
Gilles Lepoint ◽  
Laurent Bernard ◽  
Sylvie Gobert ◽  
Loïc N. Michel
Keyword(s):  
Stable Isotope ◽  
Isotopic Niche ◽  
Bayesian Approaches ◽  
Carbon And Nitrogen ◽  
Trophic Relationship ◽  
Niche Differences ◽  
Niche Metrics ◽  
Predator Interactions ◽  
The Individual ◽  
Preferential Feeding

The by-the-wind sailor Velella velella (Linnaeus, 1758) and its predator, the violet snail Janthina globosa (Swainson, 1822) are both floating neustonic organisms. Despite their global oceanic distribution and widespread blooms of V. velella in recent years, many gaps remain in our understanding about prey/predator interactions between these two taxa. Using stable isotope ratios of carbon and nitrogen, we aimed to study the trophic relationship between V. velella and J. globosa and investigate diet variation of V. velella and J. globosa in relation to individuals’ size. Bayesian approaches were used to calculate isotopic niche metrics and the contribution of V. velella to the J. globosa diet. Our data showed that the isotopic niche of V. velella differed markedly from that of J. globosa. It was larger and did not overlap that of the J. globosa, indicating a more variable diet but at a lower trophic level than J. globosa. The isotopic niche of V. velella also varied according to the size class of the individual. Small individuals showed a larger isotopic niche than larger animals and low overlap with those of the larger individuals. J. globosa displayed very low isotopic variability and very small isotopic niches. In contrast, there were no isotopic composition nor isotopic niche differences between J. globosa of any size. This very low isotopic variability suggested that J. globosa is a specialist predator, feeding, at least in this aggregation, principally on V. velella. Moreover, outputs of a stable isotope mixing model revealed preferential feeding on medium to large ( 500 mm2) V. velella colonies. While our isotopic data showed the trophic relationship between V. velella and J. globosa, many questions remain about the ecology of these two organisms, demonstrating the need for more fundamental studies about neustonic ecosystems.

TRANSFER EFFICIENCY FROM PRIMARY PRODUCERS TO RUDITAPES PHILIPPINARUM ON AN INTERTIDAL FLAT IN HIROSHIMA BAY, JAPAN

2017 ◽  
Author(s):  
Sosuke Otani ◽  
Sosuke Otani ◽  
Akira Umehara ◽  
Akira Umehara ◽  
Haruka Miyagawa ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Secondary Production ◽  
Isotope Ratios ◽  
Ruditapes Philippinarum ◽  
Transfer Efficiency ◽  
Food Sources ◽  
Stable Isotope Ratios ◽  
Primary Producers ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen

Fish yields of Ruditapes philippinarum have been decreased and the resources have not yet recovered. It needs to clarify food sources of R. philippinarum, and relationship between primary and secondary production of it. The purpose on this study is to reveal transfer efficiency from primary producers to R. philippinarum and food sources of R. philippinarum. The field investigation was carried out to quantify biomass of R. philippinarum and primary producers on intertidal sand flat at Zigozen beach in Hiroshima Bay, Japan. In particular, photosynthetic rates of primary producers such as Zostera marina, Ulva sp. and microphytobenthos were determined in laboratory experiments. The carbon and nitrogen stable isotope ratios for R. philippinarum and 8 potential food sources (microphytobenthos, MPOM etc) growing in the tidal flat were also measured. In summer 2015, the primary productions of Z. marina, Ulva sp. and microphytobenthos were estimated to be 70.4 kgC/day, 43.4 kgC/day and 2.2 kgC/day, respectively. Secondary production of R. philippinarum was 0.4 kgC/day. Contribution of microphytobenthos to R. philippinarum as food source was 56-76% on the basis of those carbon and nitrogen stable isotope ratios. Transfer efficiency from microphytobenthos to R. philippinarum was estimated to be 10-14%. It was suggested that microphytobenthos might sustain the high secondary production of R. philippinarum, though the primary production of microphytobenthos was about 1/10 compared to other algae.

Stabilization of Organic Carbon and Nitrogen in Consolidating Benthal Deposits

1985 ◽  
Vol 17 (6-7) ◽  
pp. 929-940 ◽  
Author(s):  
C. W. Bryant ◽  
L. G. Rich
Keyword(s):  
Organic Carbon ◽  
Model Verification ◽  
Volatile Acid ◽  
Free Energies ◽  
Organic Loading ◽  
Carbon And Nitrogen ◽  
Loading Rates ◽  
Degradation Reactions ◽  
The Individual ◽  
Organic Deposits

The objective of this research was to develop and validate a predictive model of the benthal stabilization of organic carbon and nitrogen in deposits of waste activated sludge solids formed at the bottom of an aerated water column, under conditions of continual deposition. A benthal model was developed from a one-dimensional, generalized transport equation and a set of first-order biological reactions. For model verification, depth profiles of the major interstitial carbon and nitrogen components were measured from a set of deposits formed in the laboratory at 20°C and a controlled loading rate. The observed sequence of volatile acid utilization in each benthal deposit was that which would be predicted by the Gibbs free energies of the individual degradation reactions and would be controlled by the reduction in interstitial hydrogen partial pressure with time. Biodegradable solids were solubilized rapidly during the first three weeks of benthal retention, but subsequent solubilization occurred much more slowly. The benthal simulation effectively predicted the dynamics of consolidating, organic deposits. Simulation of organic loading rates up to 250 g BVSS/(m2 day) indicated that the stabilization capacity of benthal deposits was far above the range of organic loading rates currently used in lagoon design.

scholarly journals Trophic Relationships and Habitat Preferences of Delphinids from the Southeastern Brazilian Coast Determined by Carbon and Nitrogen Stable Isotope Composition

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e82205 ◽  
Author(s):  
Tatiana Lemos Bisi ◽  
Paulo Renato Dorneles ◽  
José Lailson-Brito ◽  
Gilles Lepoint ◽  
Alexandre de Freitas Azevedo ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotope Composition ◽  
Habitat Preferences ◽  
Trophic Relationships ◽  
Brazilian Coast ◽  
Stable Isotope Composition ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen

Carbon and nitrogen stable isotope signatures of deep-sea meiofauna follow oceanographical gradients across the Southern Ocean

2013 ◽  
Vol 110 ◽  
pp. 69-79 ◽  
Author(s):  
Gritta Veit-Köhler ◽  
Katja Guilini ◽  
Ilka Peeken ◽  
Petra Quillfeldt ◽  
Christoph Mayr
Keyword(s):  
Stable Isotope ◽  
Southern Ocean ◽  
Deep Sea ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen ◽  
Stable Isotope Signatures

Alteration of the carbon and nitrogen stable isotope composition of beef by substitution of grass silage with maize silage

2005 ◽  
Vol 19 (14) ◽  
pp. 1937-1942 ◽  
Author(s):  
Bojlul Bahar ◽  
Frank J. Monahan ◽  
Aidan P. Moloney ◽  
Padraig O'Kiely ◽  
Charlie M. Scrimgeour ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Isotope Composition ◽  
Stable Isotope Composition ◽  
Maize Silage ◽  
Nitrogen Stable Isotope ◽  
Carbon And Nitrogen ◽  
Grass Silage

Catacomb culture wagons of the Eurasian steppes

Antiquity ◽  
2014 ◽  
Vol 88 (340) ◽  
pp. 378-394 ◽  
Author(s):  
N.I. Shishlina ◽  
D.S. Kovalev ◽  
E.R. Ibragimova
Keyword(s):  
Stable Isotope ◽  
Isotope Analysis ◽  
Burial Mound ◽  
Careful Selection ◽  
Southern Russia ◽  
The Subject ◽  
The Individual ◽  
Wheeled Vehicles ◽  
Selection Of ◽  
Catacomb Culture

The origin and development of wheeled vehicles continues to fascinate today no less than when Stuart Piggott (1974) first wrote about the subject inAntiquity40 years ago. A growing number of examples from the steppes of southern Russia and Ukraine are providing new insights into the design and construction of these complex artefacts. A recent example from the Ulan IV burial mound illustrates the techniques employed and the mastery of materials, with careful selection of the kinds of wood used for the wheels, axles and other elements. Stable isotope analysis of the individual interred in this grave showed that he had travelled widely, emphasising the mobility of steppe populations.

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