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.

Potential fluctuation of δ13C and δ15N values of small pelagic forage fish in the Sea of Japan and East China Sea

2021 ◽  
Author(s):  
Seiji Ohshimo ◽  
Taketoshi Kodama ◽  
Tohya Yasuda ◽  
Satoshi Kitajima ◽  
Toshihiro Tsuji ◽  
...  
Keyword(s):  
East China Sea ◽  
Sea Of Japan ◽  
East China ◽  
Forage Fish ◽  
The Sea Of Japan ◽  
Δ13c And Δ15n ◽  
Potential Fluctuation ◽  
China Sea

scholarly journals Contributions of riverborne inorganic and organic matters to the benthic food web in the East China Sea as inferred from stable isotope ratios

2013 ◽  
Vol 10 (1) ◽  
pp. 1051-1081
Author(s):  
N. N. Chang ◽  
J. C. Shiao ◽  
G. C. Gong ◽  
S. J. Kao ◽  
C. H. Hsieh
Keyword(s):  
Stable Isotope ◽  
East China Sea ◽  
Food Source ◽  
East China ◽  
The East China Sea ◽  
Inner Shelf ◽  
Organic Matters ◽  
Δ13c Values ◽  
China Sea ◽  
Benthic Consumers

Abstract. Coastal areas adjoining rivers are nourished by both the riverborne nutrients and organic matters. Annually, the East China Sea (ECS) receives large quantities of particulate organic carbon transported from the Changjiang (Yangtze River), as well as nutrients, which have brought about high primary production in the ECS. This study evaluated the respective contributions of terrigenous organic matters (allochthonous food source) and nutrient-induced marine production (autochthonous food source) to the ECS benthic ecosystem by analyzing the stable isotope compositions for zooplankton, benthic crustacea and demersal fish. Zooplankton exhibited consistently higher δ13C values (−21.31‰ ~ −19.22‰) in the inner shelf than in the outer shelf. The δ13C signals of fish (−19.64‰ ~ −13.46‰) and crustacea (−18.87‰ ~ −15.00‰) showed strong reliance on the marine production across the ECS continental shelf, regardless of distance from the shore. Moreover, the benthic crustacea and fish exhibited significantly higher δ13C values in the highly productive inshore sites and the δ13C values decreased seawards, implying a higher intrusion of atmospheric CO2 and lower photosynthetic fractionation due to algal blooming in the inner shelf. The δ13C values of fish also showed significant positive correlations with the concentration of surface chlorophyll a and nitrogen. Riverborne nutrients closely linked marine benthic consumers to the terrestrial watershed and tightly coupled the pelagic and benthic ecosystems in the ECS. The stable isotope compositions of benthic consumers can act as an indicator for pelagic trophic status. The future research combining analyses of stable isotope and community structure may improve assessment on the balance between contribution and risk of phytoplankton blooms.

scholarly journals Trophic Plasticity of Bombay Duck (Harpadon nehereus) in the South-Central East China Sea Based on Stable Isotope Evidence

2021 ◽  
Vol 8 ◽  
Author(s):  
Pu-Qing Song ◽  
Hu-Shun Zhang ◽  
Xin-Qing Zheng ◽  
Yuan-Yuan Li ◽  
Long-Shan Lin ◽  
...  
Keyword(s):  
Body Size ◽  
Stable Isotope ◽  
East China Sea ◽  
Food Availability ◽  
East China ◽  
The South ◽  
Trophic Plasticity ◽  
China Sea ◽  
South Central ◽  
Bombay Duck

High trophic plasticity is often invoked to explain the successful expansion of many aquatic species. Bombay duck (BD) outcompete other traditionally commercial fishes in the East China Sea (ECS) in recent years, displaying a continuous and sharp increase of catches, however, little is known whether the competition advantage of BD was related to its trophic plasticity. Using stable isotope analysis (SIA), we investigated the trophic ecology of BD in the south-central ECS in two periods. Significant differences in δ13C and δ15N values were found between sampling months and among body sizes. Modal (95% credibility limits) estimation showed that BD’s trophic position (TP) gradually increased from 3.56 (3.31–3.82) in G1 (120–150 mm for body size) to 4.09 (3.69–4.50) in G5 (241–270 mm) in November, and from 3.37 (2.92–3.88) in G2 (151–180 mm) to 3.66 (3.07–4.23) in G4 (211–240 mm) in April, respectively, suggesting obvious ontogenetic variation of δ15N and TP. More importantly, the TP of BD within the same body size showed wide amplitude, indicating BD possess high trophic plasticity, and can capture prey from low to high trophic levels. Further quantitative analysis based on the MixSIAR model showed that BD mainly fed on zooplankton and fish, but its feeding habit was characterized by the consumption of gradually reduced zooplankton and increased fish associated with increased body size. Interestingly, the fish’s contribution to BD showed obvious seasonal variation. It can be explained by varied food availability in ECS. Relatively low fish prey in April forced BD to adjust its diet, adding the ingestion of shrimps and cephalopods corresponding to temporal variations in food availability. The present study provides the evidence that high trophic plasticity exists in the feeding strategy of BD, which is reflected in the ability to adjust the feeding preference according to nutritional needs and food environmental changes; thus, it is competitively advantageous and may partly explain why BD is becoming the predominant species and displays an extensive distribution in the ECS.

Trace elements and stable isotopes (δ13C and δ15N) in shallow and deep-water organisms from the East China Sea

2008 ◽  
Vol 156 (3) ◽  
pp. 862-873 ◽  
Author(s):  
Kwadwo Ansong Asante ◽  
Tetsuro Agusa ◽  
Hiroko Mochizuki ◽  
Karri Ramu ◽  
Suguru Inoue ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Trace Elements ◽  
East China Sea ◽  
Deep Water ◽  
East China ◽  
The East China Sea ◽  
Δ13c And Δ15n ◽  
China Sea

The East China Sea Seafloor Observatory and its upgraded project

2011 ◽  
Author(s):  
Huiping Xu ◽  
Changwei Xu ◽  
Rufu Qin ◽  
Yang Yu ◽  
Shangqin Luo ◽  
...  
Keyword(s):  
East China Sea ◽  
East China ◽  
The East China Sea ◽  
China Sea ◽  
Seafloor Observatory
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