scholarly journals Evaluating quantitative fatty acid signature analysis (QFASA) in fish using controlled feeding experiments

2016 ◽  
Vol 73 (8) ◽  
pp. 1222-1229 ◽  
Author(s):  
Austin Happel ◽  
Logan Stratton ◽  
Colleen Kolb ◽  
Chris Hays ◽  
Jacques Rinchard ◽  
...  

Accurate diet estimation has long been a challenging issue for researchers investigating predators because of constraints associated with stomach content analyses. Fatty acid signature analysis offers an alternative avenue to study long-term diet trends in consumers. Despite the wealth of experiments involving fatty acids of fish and their diets, few have evaluated quantitative fatty acid signature analysis (QFASA) with fish consumers. To this end, we fed juvenile lake trout (Salvelinus namaycush), round goby (Neogobius melanostomus), and yellow perch (Perca flavescens) various invertebrate species and back-classified each predator to its respective prey using only fatty acids. Estimates were highly accurate when metabolism of diets was natively accounted for by using fatty acid profiles of predators fed known diets as the “prey library”. While highly accurate results were obtained, accounting for each predator–prey relationship limits the use of QFASA to predators that consume a limited number of species. We call for specific knowledge as to how fatty acid profiles reflect each predator–prey interaction before attempting to use fatty acids to quantify a consumer’s diet. Only after incorporating such data will QFASA provide an accurate view of individual’s diets when stomach content data are not available or are invalid.

2020 ◽  
Vol 8 (12) ◽  
pp. 1030
Author(s):  
Junbo Zhang ◽  
Chonglan Ren ◽  
Hu Zhang ◽  
Fang Yin ◽  
Shuo Zhang ◽  
...  

The dynamic predator–prey relations in the food web are vital for understanding the function and structure of ecosystems. Dietary estimation is a research hotspot of quantitative ecology, providing key insights into predator–prey relationships. One of the most promising approaches is quantitative fatty acid signature analysis (QFASA), which is the first generation of statistical tools to estimate the quantitative trophic predator–prey relationships by comparing the fatty acid (FA) signatures among predators and their prey. QFASA has been continuously widely applied, refined and extended since its introduction. This article reviewed the research progress of QFASA from development and application. QFASA reflects the long-term diet of predator, and provides the quantitative dietary composition of predator, but it is sensitive to the metabolism of predator. The calibration coefficients (CCs) and the FA subset are two crucial parameters to explain the metabolism of predators, but the incorrect construction or improper use of CCs and the FA subset may cause bias in dietary estimation. Further study and refinement of the QFASA approach is needed to identify recommendations for which CCs and subsets of FA work best for different taxa and systems.


2018 ◽  
Vol 75 (1) ◽  
pp. 95-105 ◽  
Author(s):  
Austin Happel ◽  
Jory L. Jonas ◽  
Paul R. McKenna ◽  
Jacques Rinchard ◽  
Ji Xiang He ◽  
...  

Despite long-term efforts to restore lake trout (Salvelinus namaycush) populations in the Great Lakes, they continue to experience insufficient recruitment and rely on hatchery programs to sustain stocks. As lake trout reproductive success has been linked to diets, spatial heterogeneity in diet compositions is of interest. To assess spatial components of adult lake trout diets, we analyzed stomach contents and fatty acid profiles of dorsal muscle collected throughout Lake Michigan and along Lake Huron’s Michigan shoreline. Lake trout from Lake Huron were generally larger in both length and mass than those from Lake Michigan. However, lake trout from Lake Michigan varied more in size based on depth of capture with smaller fish being caught more in deeper set nets. Fatty acids and stomach contents indicated that alewife (Alosa pseudoharengus) were consumed more in western Lake Michigan in contrast with round goby (Neogobius melanostomus) along the eastern shoreline. Conversely, in Lake Huron, lake trout primarily consumed rainbow smelt (Osmerus mordax). These results indicate that diet compositions of lake trout populations are relatively plastic and offer new insights into within-basin heterogeneity of Great Lakes food webs.


2020 ◽  
Vol 375 (1804) ◽  
pp. 20190650 ◽  
Author(s):  
Jakob Kühn ◽  
Kevin Tobias ◽  
Alexander Jähngen ◽  
Liliane Ruess

Quantitative fatty acid signature analysis (QFASA) is widely used to investigate trophic interactions in marine ecosystems, as nutritionally important ω 3 long-chain polyunsaturated fatty acids at the food web base allow tracing of their trophic transfer in the food chain. By contrast, the basal resources in soil food webs comprise a wider array of trophic markers, including branched-chain, cyclopropane as well as several mono- and polyunsaturated fatty acids. These diverse markers allow distinguishing between the three dominant soil carbon and energy channels, the root, bacterial and fungal pathway. QFASA has not been applied yet to soil ecosystems owing to the lack of a priori data to fit the model. The present work investigates the transfer of absolute and relative trophic marker fatty acids into Collembola as dominant representatives of the soil mesofauna. Three different species were fed on a variety of single diets characteristic for the green and brown food chain. Calibration coefficients were calculated and diet estimation trials for mixed diet set-ups were performed, using a library comprising 50 different resources. However, estimation of Collembola diet was only partially successful, identifying the main components, but not the correct relative proportions. Adjustments by fat content or diet group exclusion did not improve the results. Nonetheless, this work provides, to our knowledge, a first comprehensive dataset to translate the application of QFASA from marine to soil ecosystems. This article is part of the theme issue ‘The next horizons for lipids as ‘trophic biomarkers’: evidence and significance of consumer modification of dietary fatty acids’.


1997 ◽  
Vol 75 (2) ◽  
pp. 188-197 ◽  
Author(s):  
S. J. Iverson ◽  
J. P. Y. Arnould ◽  
I. L. Boyd

Fatty acid signature analysis is based on the principle that unique arrays of fatty acids within groups of organisms can be transferred, largely unaltered, up the marine food chain and thus may be an indicator of diet composition. We applied fatty acid signature analysis to milks collected from Antarctic fur seals (Arctocephalus gazella) at South Georgia in 1990–1991, during the perinatal period (N = 19) and subsequently during early (N = 11), mid (N = 11), and late (N = 8) foraging trips. In lactating otariid females, milk fatty acids secreted during the perinatal fast are derived largely from blubber mobilization and thus are influenced by dietary history prior to parturition. Conversely, milk fatty acids secreted during foraging trips are derived primarily from immediate dietary intake. The fatty acid signature of perinatal milks was significantly different from that of all other milks, suggesting differences in the prepartum diet when females are away from the breeding grounds. At the onset of foraging periods, the fatty acid composition of milks' changed dramatically to reflect a diet composed mainly of krill. However, during late foraging periods, milk fatty acids again changed from those of early and mid foraging, and suggested a predominance of teleost fish in the diet. These findings were consistent with independent assessments of diet by faecal analysis and indicate the potential value of fatty acid signature analysis in studying foraging ecology in free-ranging pinnipeds.


2019 ◽  
Author(s):  
L Chavarie ◽  
J. Hoffmann ◽  
A.M. Muir ◽  
C.C. Krueger ◽  
C.R. Bronte ◽  
...  

AbstractFatty acids are well-established biomarkers used to characterize trophic ecology, food-web linkages, and the ecological niche of many different taxa. Most often, fatty acids that are examined include only those previously identified as “dietary” or “extended dietary” biomarkers. Fatty acids considered as non-dietary biomarkers, however, represent numerous fatty acids that can be extracted. Some studies may include non-dietary fatty acids (i.e., combined with dietary fatty acids), but do not specifically assess them, whereas in other studies, these data are discarded. In this study, we explored whether non-dietary biomarkers fatty acids can provide worthwhile information by assessing their ability to discriminate intraspecific diversity within and between lakes. Non-dietary fatty acids used as biomarkers delineated variation among regions, among locations within a lake, and among ecotypes within a species. Physiological differences that arise from differences in energy processing can be adaptive and linked to habitat use by a species’ ecotypes, and likely explains why non-dietary fatty acids biomarkers can be a relevant tool to delineate intraspecific diversity. Little is known about the non-dietary-mediated differences in fatty acid composition, but our results showed that non-dietary fatty acids biomarkers can be useful tool in identifying variation.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hung Van Le ◽  
Don Viet Nguyen ◽  
Quang Vu Nguyen ◽  
Bunmi Sherifat Malau-Aduli ◽  
Peter David Nichols ◽  
...  

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 319-319
Author(s):  
Carrie James ◽  
Sandra L Rodriguez-Zas ◽  
Maria R C de Godoy

Abstract There is evidence that algae can be a sustainable alternative of omega-3 polyunsaturated fatty acids (w-3 PUFA; DHA and EPA) in the diets of felines, but more information is needed to determine bioavailability of algal w-3 PUFAs in felines. Therefore, the objective of this study was to determine the effects of dietary supplementation of algae DHA on plasma and red blood cell (RBC) membrane fatty acid profiles and fecal microbiota of adult cats. A complete randomized design was utilized with thirty female and male adult cats (mean age: 1.8 ± 0.03 yr, mean BW: 4.5 ± 0.8 kg) which were fed an assigned diet for 90 d. Three diets were formulated with poultry fat alone or inclusion of 2% fish oil or 2% algae DHA meal. Blood samples were collected after fasting on 0, 30, 60 and 90 d to be analyzed for plasma and red blood cell fatty acid profiles. A fresh fecal sample was collected within 15 min of defecation from each cat to be analyzed for fecal microbiota. Illumina 16S rRNA sequencing from V4 region was completed using MiSeq and analyzed using QIIME 2. Plasma and RBC fatty acid concentrations at baseline were similar among all cats and treatment groups. However, dietary treatment had a significant effect on the concentrations of several fatty acids in plasma and RBC over time. Plasma and RBC concentrations of DHA were greater (P < 0.05) for cats fed the algal DHA diet compared to the control and fish oil diets. Conversely, plasma and RBC concentrations of EPA did not differ among treatments when analyzed as a change from baseline. Beta- and alpha-diversity did not differ among treatments, indicating that 2% fish oil or algal-DHA meal does alter fecal microbiota of cats in contrast with cats fed a poultry fat-based diet.


2020 ◽  
Vol 15 (1) ◽  
pp. 606-618 ◽  
Author(s):  
Dani Dordevic ◽  
Ivan Kushkevych ◽  
Simona Jancikova ◽  
Sanja Cavar Zeljkovic ◽  
Michal Zdarsky ◽  
...  

AbstractThe aim of this study was to simulate olive oil use and to monitor changes in the profile of fatty acids in home-made preparations using olive oil, which involve repeated heat treatment cycles. The material used in the experiment consisted of extra virgin and refined olive oil samples. Fatty acid profiles of olive oil samples were monitored after each heating cycle (10 min). The outcomes showed that cycles of heat treatment cause significant (p < 0.05) differences in the fatty acid profile of olive oil. A similar trend of differences (p < 0.05) was found between fatty acid profiles in extra virgin and refined olive oils. As expected, the main differences occurred in monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). Cross-correlation analysis also showed differences between the fatty acid profiles. The most prolific changes were observed between the control samples and the heated (at 180°C) samples of refined olive oil in PUFAs, though a heating temperature of 220°C resulted in similar decrease in MUFAs and PUFAs, in both extra virgin and refined olive oil samples. The study showed differences in fatty acid profiles that can occur during the culinary heating of olive oil. Furthermore, the study indicated that culinary heating of extra virgin olive oil produced results similar to those of the refined olive oil heating at a lower temperature below 180°C.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4080
Author(s):  
Milena Bučar Miklavčič ◽  
Fouad Taous ◽  
Vasilij Valenčič ◽  
Tibari Elghali ◽  
Maja Podgornik ◽  
...  

In this work, fatty-acid profiles, including trans fatty acids, in combination with chemometric tools, were applied as a determinant of purity (i.e., adulteration) and provenance (i.e., geographical origin) of cosmetic grade argan oil collected from different regions of Morocco in 2017. The fatty acid profiles obtained by gas chromatography (GC) showed that oleic acid (C18:1) is the most abundant fatty acid, followed by linoleic acid (C18:2) and palmitic acid (C16:0). The content of trans-oleic and trans-linoleic isomers was between 0.02% and 0.03%, while trans-linolenic isomers were between 0.06% and 0.09%. Discriminant analysis (DA) and orthogonal projection to latent structure—discriminant analysis (OPLS-DA) were performed to discriminate between argan oils from Essaouira, Taroudant, Tiznit, Chtouka-Aït Baha and Sidi Ifni. The correct classification rate was highest for argan oil from the Chtouka-Aït Baha province (90.0%) and the lowest for oils from the Sidi Ifni province (14.3%), with an overall correct classification rate of 51.6%. Pairwise comparison using OPLS-DA could predictably differentiate (≥0.92) between the geographical regions with the levels of stearic (C18:0) and arachidic (C20:0) fatty acids accounting for most of the variance. This study shows the feasibility of implementing authenticity criteria for argan oils by including limit values for trans-fatty acids and the ability to discern provenance using fatty acid profiling.


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