Methyl esters from the copepod Tisbe biminiensis assayed by two transesterification methods (original) (raw)
Related papers
Effect of diet on the fatty acid composition of the copepod Tisbe biminiensis
Journal of Crustacean Biology, 2013
Success in rearing fish depends on the nutritional content of food offered to the larvae. The aim of this study was to test the effect of diets on fatty acid composition of the copepod Tisbe biminiensis Volkmann-Rocco, 1973 as a food source. The copepods were reared in 5 l vessels with aeration at 29-31°C, salinity 30-35, and natural photoperiod of 13 hours light/11 hours dark. The copepods were fed two diets: a mixture of microalgae Thalassiosira weissflogii and commercial fish food, and only the fish food. Lipids were extracted with chloroform and methanol and esterified by acid catalysis with BF 3 . Three replicates were used in each treatment. Fatty acids were identified by comparison of retention times and co-injection with standard Mix C4-C24 using GC and GCMS apparatus. Thirty-one and 29 fatty acids were detected on copepods fed mixed diets and fish food, respectively. The most abundant fatty acids in copepod fed mixed a diet were C18, C16, and C12. In the other treatment, predominant fatty acids were C18, C16, and C20:2. Thirty-one and 30 fatty acids were detected in the fish food and the microalgae, respectively. The predominant fatty acids of microalgae were C18, C21, and C20:2. For fish food, the predominant fatty acids were C16, C18, and C18:1n9. Essential fatty acids were detected and EPA and DHA contents of copepods fed mixture were significantly higher compared to those fed only ration, indicating that the mixed diet provided better source of HUFA for T. biminiensis. However, its DHA level was lower than other harpacticoid copepods. This suggests that T. biminiensis either needs to be fed a better quality diet, or be enriched with some fatty acids before they are offered to the cobia larvae. The copepod T. biminiensis is capable of bio-converting fatty acid C18:0 into chains with 20 unsaturated carbons. T. biminiensis fed mixed a diet or the fish food alone showed DHA/EPA ratios of 1.3 and 3.3, respectively, suggesting that this copepod species may be suitable for use in fish larviculture.
Journal of The Chilean Chemical Society, 2009
This work presents the fatty acid composition of copepod species in southern Chile: two of them that are ectoparasites on Eleginops maclovinus (Caligus rogercresseyi and Lepeophtheirus mugiloidis) and one free-living species (Tigriopus sp.). C. rogercresseyi females from different hosts (Salmo salar and E. Maclovinus). Fatty acid methyl esters were determined with GC-MS. The studied species presented a wide variety of saturated, monounsaturated, and polyunsaturated fatty acids, with compounds having from 12 to 24 carbons. The studied species had different percentage compositions of the acids identified. In all three species, palmitic (C 16) and oleic (C 18:1) fatty acids dominated the percentage concentrations. The highest percentage concentration (46.59 %) was found for palmitic acid in Tigriopus. Only the females of C. rogercresseyi analyzed were found to have myristoleic acid (C 14:1). Stearic (C 18) and oleic (C 18:1) acids were present in both C. rogercresseyi males and females, but with different distributions. Oleic acid in females was 33.97 % and only 7.64 % in males, whereas stearic acid was 9.95 % in females and 21.51 % in males. The C. rogercresseyi on Patagonian blennie (Eleginops maclovinus) revealed 3.89% C 20:4 and 9.60 % C 20:5. Eicosapentaenoic and docosahexaenoic acids, detected only in the ectoparasitic copepods, had percentage concentrations of up to 10 %. The possible role of this fatty acid in the stimulation of innate fish immunity is discussed.
Journal of Plankton Research, 2012
Tisbe furcata, Nitokra lacustris, Calanus finmarchicus and Calanus glacialis were reared for several months in the laboratory prior to feeding selected diets. Copepods were fed Isochrysis galbana, Tetraselmis sp., Dunaliella tertiolecta, Thalassiosira pseudonana, Rhodomonas sp., Rhodomonas lens and Oxyrrhis marina individually or in combination. Oxyrrhis marina itself was fed up to four of the algae species. The lipid class and fatty acid composition of the copepods was determined and compared with each other, the diets and with wild C. finmarchicus, C. glacialis and Pseudocalanus sp. Cultured O. marina, T. furcata and N. lacustris had greater proportions of essential 22:6v3 or 20:5v3 acids than in their diets suggesting nutritional enrichment through synthesis or preferential retention. Lower proportions of 18:3v3 than in their diets fed individually or in combination suggests desaturation and elongation of 18:3v3. Stable isotope analysis of the heterotroph samples and their dietary sources revealed similar values for 18:3v3 in each dietary pair and different ones for 22:6v3 and 20:5v3 supporting derivation from precursors rather than trophic magnification. Principal components analysis of copepods and their diets showed cultured Calanus spp. to have the most similar fatty acid composition to their diet indicating little modification or sequestration of polyunsaturated fatty acids.
Marine Chemistry, 2012
Two of the dominant Southern Ocean copepods, Calanus simillimus and Calanus propinquus, are known for their lipid storage via triacylglycerols indicating year-round activity, as opposed to diapausing species, which accumulate wax esters. We studied the lipid and fatty acid compositions of C. simillimus (CV stages) with focus on its ability to produce unusually long-chain monounsaturated fatty acids. Besides the biosynthesis of high-energy fatty acids with 20 and 22 carbon atoms, the occurrence of fatty acids with 24 carbon atoms accounting for up to 15% of total fatty acids is intriguing. Their double bond positions were unequivocally determined as (n−9), (n−11) and (n−13) by DMOX derivatisation. The dominant isomer was 24:1(n−11) contributing up to 8% to the total fatty acids. The major fatty acids were the isomers 22:1(n−11) and (n−9) averaging 20% and 10%, respectively. A re-evaluation of fatty acid data of C. propinquus also revealed 24:1 fatty acids exhibiting on average 5% with (n − 11) and (n − 9) as main isomers. The principal fatty acids were also 22:1(n − 11) and (n − 9), but in contrast to C. simillimus both fatty acids occurred in equally high amounts of about 20%. The de novo biosynthesis of these long-chain monounsaturated fatty acids generally represents a very efficient energy storage mode. Chain elongation to 22 and even to 24 carbon atoms in C. propinquus and further optimised by C. simillimus yields high-energy compounds for these triacylglycerol-storing copepods. Biosynthetic pathways for the fatty acids are proposed and discussed in view of the well-adapted life cycle strategies of the two species, which have to cope with a pronounced seasonal food supply in the Southern Ocean.
Marine Ecology Progress Series, 2012
Polyunsaturated fatty acids (PUFA) are essential compounds that can limit the productivity of primary consumers in aquatic food webs, where the efficiency in energy transfer at the plant-animal interface has been related to food quality in terms of fatty acids (FA). At this interface, copepods play a pivotal role both as consumers of primary production and as a food source for higher trophic levels. Understanding the role of grazing copepods in the transfer of FA is therefore essential for our knowledge on the overall functioning of marine ecosystems. The harpacticoid copepod Microarthridion littorale grazed for 9 d on 13 C labelled diatoms and bacteria in the laboratory and was then subjected to FA-specific stable isotope analysis. The objective of this analysis was to inspect the copepod's ability to bioconvert short-chain FA (SC-PUFA, < 20 carbons) into long-chain PUFA (LC-PUFA, ≥20 carbons) and the FA involved in the potential bioconversion pathways. Diatoms and bacteria were chosen as test diets because of their different FA composition, i.e. docosahexaenoic acid (DHA; 22:6ω3) was absent in the bacteria, and eicosapentaenoic acid (EPA; 20:5ω3) was < 5% of the total FA weight of bacteria. The presence of labelled DHA in copepods feeding on bacteria showed that this PUFA must have been converted from other FA, possibly EPA. The FA composition of copepods in the laboratory was different from that of field copepods, which suggests the availability of more food sources in the field than those offered in the experiment. The weight proportion of C18 FA decreased in copepods feeding on either bacteria or diatoms relative to field copepods, while the proportion of both EPA and DHA increased. In contrast to planktonic calanoid copepods that have limited ability to bioconvert FA, benthic harpacticoid copepods apparently developed the ability to elongate FA and to exploit niches with poor quality food. Moreover, by improving the quality of the food they graze upon, especially in terms of EPA and DHA, harpacticoid copepods upgrade the nutritive value of food available to the higher trophic levels in marine food webs.
Frontiers in Marine Science, 2022
Consumer regulation of lipid composition during assimilation of dietary items is related to their ecology, habitat, and life cycle, and may lead to extra energetic costs associated with the conversion of dietary material into the fatty acids (FAs) necessary to meet metabolic requirements. For example, lipid-rich copepods from temperate and polar latitudes must convert assimilated dietary FAs into wax esters, an efficient type of energy storage which enables them to cope with seasonal food shortages and buoyancy requirements. Lipidpoor copepods, however, tend to not be as constrained by food availability as their lipidrich counterparts and, thus, should have no need for modifying dietary FAs. Our objective was to test the assumption that Temora longicornis, a proxy species for lipid-poor copepods, does not regulate its lipid composition. Isotopically-enriched (13 C) diatoms were fed to copepods during a 5-day laboratory experiment. Compound-specific stable isotope analysis of algae and copepod samples was performed in order to calculate dietary FA assimilation, turnover, and assimilation efficiency into copepod FAs. Approximately 65% of the total dietary lipid carbon (C) assimilated (913 ± 68 ng C ind-1 at the end of the experiment) was recorded as polyunsaturated FAs, with 20 and 15% recorded as saturated and monounsaturated FAs, respectively. As expected, T. longicornis assimilated dietary FAs in an unregulated, non-homeostatic manner, as evidenced by the changes in its FA profile, which became more similar to that of their diet. Copepods assimilated 11% of the total dietary C (or 40% of the dietary lipid C) ingested in the first two days of the experiment. In addition, 34% of their somatic growth (in C) after two days was due to the assimilation of dietary C in FAs. Global warming may lead to increased proportions of smaller copepods in the oceans, and to a lower availability of algae-produced essential FAs. In order for changes in the energy transfer in marine food webs to be better understood, it is important that future investigations assess a broader range of diets as well as lipid-poor zooplankton from oceanographic areas throughout the world's oceans.
Fatty Acid Composition in Cultured Amphiascoides neglectus (Copepoda: Harpacticoida)
Ecology and Sustainable Development, 2019
This study investigates the effect of salinity on the fatty acid profile of a harpacticoid copepod Amphiascoides neglectus exposed to constant laboratory lighting and temperature (25-26 o C) at pH7 for 40 days. The results were compared with those cultured in the common open hatchery environment which is almost the same as in the natural ecosystem. Different fatty acid levels were determined using Gas Chromatography and Mass Spectrometry (GC-MS). Results showed that there were no significant differences (p>0.05) in fatty acid content for both 20ppt and 30ppt treatment but the percentage of EPA was higher in 20ppt. Harpacticoid copepods in the hatchery showed significantly (p<0.05) more fatty acids in 30ppt than 20ppt. EPA was also higher in harpacticoids cultured under 30ppt. Manipulation of salinity and temperature in combination of light factor for copepod rearing system could improve the deposition of fatty acids in their body.
Polar Biology, 2002
The small, sub-ice copepod Jaschnovia brevis is rich in triacylglycerols, suggesting a feeding behaviour not constrained to the seasonal phytoplankton bloom. The copepod's triacylglycerol reserves contain: the diatom biomarkers 16:1n-7 (23.9%), 20:5n-3 (8.5%) and C16 PUFA (1.3%), the¯agellate biomarkers 18:4n-3 (3.7%) and 22:6n-3 (3.3%), and the Calanus copepod biomarkers 20:1n-9 (7.7%) and 22:1n-11 (6.2%). Total lipid from particulates in the water column contained polar lipid (45.0%), wax esters (24.9%) and triacylglycerols (11.2%) as major components. The total lipids in the particulates were rich in 18:1n-9 (31.5%) and 16:0 (21.2%), and relatively rich in 18:0 (7.8%) and 18:2n-6 (9.2%). The triacylglycerols in the particulates contained 16:1n-7 (20.7%), C16 PUFA (4.1%), 18:4n-3 (1.9%), 20:5n-3 (3.6%), 22:6n-3 (1.9%), 20:1n-9 (5.2%) and 22:1n-11 (3.9%). The polar lipids in the particulates contained 16:1n-7 (17.3%), C16 PUFA (7.8%), 18:4n-3 (3.3%), 20:5n-3 (14.5%) and 22:6n-3 (9.6%). The fatty alcohols in the wax esters of the particulates were mainly 16:0 (11.3%), 20:1n-9 (21.1%) and 22:1n-11 (30.6%). The nature of the particulates, their possible origin in living and non-living material, and their role in the nutrition of J. brevis are discussed.
Grasas y Aceites
The present study investigates the detailed lipid classes and their fatty acid (FA) compositions from two parasitic copepods Lernaeocera lusci and Peroderma cylindricum and their respective fish host species Merluccius merluccius and Sardina pilchardus. The lipid classes, including phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), triacylglycerol (TAG), wax ester/cholesterol ester (WE/CE), mono-diacylglycerol (MDG), and free fatty acids (FFA) were separated by thin layer chromatography. The results revealed that TAG and PC were the major lipid classes in parasites; while WE/CE and PS were the most abundant in hosts. As for FA composition, C16:0, C18:0, C18:1n-9, C20:5n-3, and C22:6n-3 were recurrently found to be dominant in all lipid classes of the different organisms studied. However, some differences concerning the abundance and the distribution of several FAs were observed. Overall, the obtained results highlighted that ...
Marine Biology , 2006
To test whether heterotrophic protists modify precursors of long chain n-3 polyunsaturated fatty acids (LCnÀ3PUFAs) present in the algae they eat, two algae with different fatty acid contents (Rhodomonas salina and Dunaliella tertiolecta) were fed to the heterotrophic protists Oxyrrhis marina Dujardin and Gyrodinium dominans Hulbert. These experiments were conducted in August 2004. Both predators and prey were analyzed for fatty acid composition. To further test the effects of trophic upgrading, the calanoid copepod Acartia tonsa Dana was fed R. salina, D. tertiolecta, or O. marina that had been growing on D. tertiolecta (OM-DT) in March 2005. Our results show that trophic upgrading was species-specific. The presence of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the heterotrophic protists despite the lack of these fatty acids in the algal prey suggests that protists have the ability to elongate and desaturate 18:3 (n-3), a precursor of LCnÀ3PUFAs, to EPA and/or DHA. A lower content of these fatty acids was detected in protists that were fed good-quality algae. Feeding experiments with A. tonsa showed that copepods fed D. tertiolecta had a significantly lower content of EPA and DHA than those fed OM-DT. The concentration of EPA was low on both diets, while DHA content was highest in A. tonsa fed R. salina and OM-DT. These results suggest that O. marina was able to trophically upgrade the nutritional quality of the poor-quality alga, and efficiently supplied DHA to the next trophic level. The low amount of EPA in A. tonsa suggests EPA may be catabolized by the copepod.