scholarly journals Factors affecting the fatty acid composition of mesopelagic fish of the continental slope in the South China Sea

Author(s):  
Fuqiang Wang ◽  
Ying Wu ◽  
Ying Cui ◽  
Zuozhi Chen ◽  
Zhongyi Li ◽  
...  

Study of the ecology of mesopelagic fish is central to assessing the active biological pump in the ocean, especially in the mesopelagic layer. As a consequence of the small size and pressure change, traditional stomach content analysis is not useful for analyzing the feeding behavior of mesopelagic fish. The use of δ13C and fatty acid analyses can help to resolve this problem. The mesopelagic fish examined in this study were collected from the continental slope in the north of the South China Sea (SCS), and are compared with nearshore SCS fish and fish collected from the Southern Ocean. The unusually high lipid content of the mesopelagic fish resulted in △δ13C values (i.e., the difference in δ13C between unextracted and extracted tissues) exceeding 1‰, which is more than the enrichment factor in the food web. Thus, extraction of lipids was conducted prior to δ13C isotope analysis for the study of trophic interactions of mesopelagic fish. Compared with other fish, mesopelagic fish had high C18:1n-9/C18:1n-7 and C20:1n-9/ C18:1n-7 ratios, which confirms that plankton is their main dietary source. Diatoms comprise a higher proportion of phytoplankton in the Southern Ocean and a lower proportion in the SCS, and this is reflected in the C20:5n-3/C22:6n-3 (EPA/DHA) ratio in mesopelagic fish in each region. The low EPA/DHA ratio in SCS fish indicates that diatoms are not the main component in the diet of mesopelagic fish. The SCS mesopelagic fish had higher C20:4n-6/C22:6n-3 (ARA/DHA) and C20:4n-6/C20:5n-3 (ARA/EPA) ratios than fish in the Southern Ocean. This result suggests that physical factors (e.g., temperature) also affect the fatty acid composition of these fish, particularly because certain fatty acids enable the fish to better adapt to extreme environmental conditions. Future studies of the synthesis of fatty acids in particular species should take account of both the dietary sources and physical factors in their environment.

2018 ◽  
Author(s):  
Fuqiang Wang ◽  
Ying Wu ◽  
Ying Cui ◽  
Zuozhi Chen ◽  
Zhongyi Li ◽  
...  

Study of the ecology of mesopelagic fish is central to assessing the active biological pump in the ocean, especially in the mesopelagic layer. As a consequence of the small size and pressure change, traditional stomach content analysis is not useful for analyzing the feeding behavior of mesopelagic fish. The use of δ13C and fatty acid analyses can help to resolve this problem. The mesopelagic fish examined in this study were collected from the continental slope in the north of the South China Sea (SCS), and are compared with nearshore SCS fish and fish collected from the Southern Ocean. The unusually high lipid content of the mesopelagic fish resulted in △δ13C values (i.e., the difference in δ13C between unextracted and extracted tissues) exceeding 1‰, which is more than the enrichment factor in the food web. Thus, extraction of lipids was conducted prior to δ13C isotope analysis for the study of trophic interactions of mesopelagic fish. Compared with other fish, mesopelagic fish had high C18:1n-9/C18:1n-7 and C20:1n-9/ C18:1n-7 ratios, which confirms that plankton is their main dietary source. Diatoms comprise a higher proportion of phytoplankton in the Southern Ocean and a lower proportion in the SCS, and this is reflected in the C20:5n-3/C22:6n-3 (EPA/DHA) ratio in mesopelagic fish in each region. The low EPA/DHA ratio in SCS fish indicates that diatoms are not the main component in the diet of mesopelagic fish. The SCS mesopelagic fish had higher C20:4n-6/C22:6n-3 (ARA/DHA) and C20:4n-6/C20:5n-3 (ARA/EPA) ratios than fish in the Southern Ocean. This result suggests that physical factors (e.g., temperature) also affect the fatty acid composition of these fish, particularly because certain fatty acids enable the fish to better adapt to extreme environmental conditions. Future studies of the synthesis of fatty acids in particular species should take account of both the dietary sources and physical factors in their environment.


2019 ◽  
Vol 35 (9) ◽  
pp. 788-804
Author(s):  
Fuqiang Wang ◽  
Ying Wu ◽  
Ying Cui ◽  
Zuozhi Chen ◽  
Zhongyi Li ◽  
...  

1985 ◽  
Vol 54 (03) ◽  
pp. 563-569 ◽  
Author(s):  
M K Salo ◽  
E Vartiainen ◽  
P Puska ◽  
T Nikkari

SummaryPlatelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate.There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 ω3-fatty acids in platelets (r = -0.26 - -0.40) and with the platelet 20: 5ω3/20: 4ω 6 and ω3/ ω6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5ω 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the ω6-fatty acids. Thrombin-induced aggregation correlated negatively with the ω3/6ω ratio in adipose tissue (r = -0.25) and the 20: 3ω6/20: 4ω 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4ω6 (r = 0.22) in plasma phospholipids (PL).The percentages of prostanoid precursors in platelet lipids, i. e. 20: 3ω 6, 20: 4ω 6 and 20 :5ω 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20: 5ω 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).These results suggest that, among a free-living population, relatively small changes in the fatty acid composition of plasma and platelets may be reflected in significant differences in platelet aggregation, and that an increase in linoleate-rich vegetable fat in the diet may not affect platelet function favourably unless it is accompanied by an adequate supply of ω3 fatty acids.


Author(s):  
Mohamed Haniff Hanafy Idris ◽  
Yanty Noorzianna Manaf ◽  
Mohd Nasir Mohd Desa ◽  
Amalia Mohd Hashim ◽  
Muhamad Shirwan Abdullah Sani ◽  
...  

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 941
Author(s):  
Ewa Szpunar-Krok ◽  
Anna Wondołowska-Grabowska ◽  
Dorota Bobrecka-Jamro ◽  
Marta Jańczak-Pieniążek ◽  
Andrzej Kotecki ◽  
...  

Soybean is a valuable protein and oilseed crop ranked among the most significant of the major crops. Field experiments were carried out in 2016–2019 in South-East Poland. The influence of soybean cultivars (Aldana, Annushka), nitrogen fertilizer (0, 30, 60 kg∙ha−1 N) and inoculation with B. japonicum (control, HiStick® Soy, Nitragina) on the content of fatty acids (FA) in soybean seeds was investigated in a three-factorial experiment. This study confirms the genetic determinants of fatty acid composition in soybean seeds and their differential accumulation levels for C16:0, C16:1, C18:1n9, C18:2, C18:3, and C20:0 as well saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids. Increasing the rate from 30 to 60 kg ha−1 N did not produce the expected changes, suggesting the use of only a “starter” rate of 30 kg ha−1 N. Inoculation of soybean seeds with a strain of Bradyrhizobium japonicum (HiStick® Soy, BASF, Littlehampton, UK and Nitragina, Institute of Soil Science and Plant Cultivation–State Research Institute, Puławy, Poland) is recommended as it will cause a decrease in SFA and C16:0 acid levels. This is considered nutritionally beneficial as its contribution to total fatty acids determines the hypercholesterolemic index, and it is the third most accumulated fatty acid in soybean seeds. The interaction of cultivars and inoculation formulation on fatty acid content of soybean seeds was demonstrated. An increase in the value of C16:0 content resulted in a decrease in the accumulation of C18:1, C18:2, and C18:3 acids. The content of each decreased by almost one unit for every 1% increase in C16:0 content. The dominant effect of weather conditions on the FA profile and C18:2n6/C18:3n3 ratio was demonstrated. This suggests a need for further evaluation of the genetic progress of soybean cultivars with respect to fatty acid composition and content under varying habitat conditions.


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