Lipid Classes and Fatty Acid Profile of Cultured and Wild Black Rockfish

Lipid Classes and Fatty Acid Profile of Cultured and Wild Black Rockfish, Sebastes schlegeli Hiroaki Saito＊ and Satoru Ishikawa† National Research Institute of Fisheries Science, Fisheries Research Agency, 2-12-4, Fuku-ura, Kanazawa-ku, Yokohama-shi 236-8648, Japan † ‌Present address: Shimokita Brand Research Institute, Aomori Prefectural Industrial Tech-nology Research Center (154, Ueno, Ohata, Mutsu 039-4401, Aomori, Japan).

Abstract: The lipid and fatty acid compositions of the muscle and liver of adult and juvenile black rockfish, Sebastes schlegeli, and that of its stomach contents were examined to clarify its lipid characteristic and the difference between aquacultured and wild samples. Triacylglycerols were the dominant depot lipids of all samples, while phospholipids, such as phosphatidylethanolamine and phosphatidylcholine, were found to be the major components in the polar lipids. The cultured juvenile and young samples had high levels of 18:2n- 6 (linoleic acid, 5.0% and 4.0–5.9% for TAG of juvenile and young samples) with low levels of 22:6n-3 (docosahexaenoic acid: DHA, 9.7% and 3.3–6.7% for TAG of juvenile and young samples), whereas the adults (both cultured and wild) had only trace levels of 18:2n-6 (0.6–1.3% and 1.0–1.3% for TAG of cultured and wild samples) with noticeable levels of DHA (3.3–19.7% and 5.2–11.9% for TAG of cultured and wild samples). Similar to the fatty acid profiles in TAG of both cultured and wild adult samples, those in the phospholipids of both the samples were very similar to each other. The lipid characteristics of the cultured adult S. schlegeli samples were similar to those of the wild ones, whose muscle phospholipids contained markedly high levels of DHA (38.3–40.2% for cultured and 40.1–43.5% for wild). Therefore, the nutritional values of cultured and wild adult S. schlegeli are expected to be similar.

Key words: aquaculture, docosahexaenoic acid, fish lipid, icosapentaenoic acid, linoleic acid, polyunsaturated fatty acid

1 Introduction and black（Korean）rockfish, Sebastes schlegeli, are utilized It is generally known that all marine animals, not only as a healthful and popular seafood15）. Unfortunately, in marine fishes but also invertebrates, characteristically ac- recent years, overfishing in Japan has reduced the produc- cumulate various sorts of long-chain n-3 polyunsaturated tion of wild Sebastes fishes. Black rockfish, S. schlegeli fatty acid（s PUFA）in their lipids, such as docosahexaenoic Hilgendor（f Scorpaenidae, Scorpaeniformes）, is the most acid（DHA, 22:6n-3）and icosapentaenoic acid（EPA, important commercial rockfish in Japan and Korea. Re- 20:5n-3）1）. Much attention has been brought to the lipids cently, it has been aquacultured because of its desirable and fatty acids of seawater fishes, with growing recognition taste and high value16－18）. For both consumers and produc- of the benefits of dietary fish oils1, 2）. However, compared to ers, it is important to produce good quality cultured S. pelagic fish species1－3）, little information is available on the schlegeli with high nutritious value, rich in n-3 PUFA. lipid classes and fatty acid composition of demersal fish Although a great deal of attention being paid to the eco- species except for some cultured fishes, such as sea logical and biological aspects of S. schlegeli15, 19－21）, few bream（s Pagrus major4）, Pagellus bogaraveo5）, Sparus studies on the lipid composition of the flesh of S. schlegeli aurata6－10））, and flounder（s Paralychthys olivaceous11）, Solea solea11－14） and Solea senegalensis12））. Abbreviations: DHA, docosahexaenoic acid; DMA, dimethylacetals; DMOX, 4,4-dimethyloxazoline; EPA, Rockfish（genus Sebastes, Sebastidae, Scorpaeniformes） icosapentaenoic acid; GC/MS, gas chromatography/mass is circumglobal demersal fish, the largest genus in the Se- spectrometry; MUFA, monounsaturated fatty acids; PC, bastidae family, and is present in all the world′s oceans. As phosphatidylcholine; PE, phosphatidylethanolamine; PUFA, for important sport and commercial fishes in Japan, two polyunsaturated fatty acids; TAG, triacylglycerols; TFA, total typical Sebastes species, red rockfish Sebastes inermis, fatty acids; TL, total lipids.

＊Correspondence to: Hiroaki Saito, National Research Institute of Fisheries Science, 2-12-4 Fuku-ura, Kanazawa-ku, Yokohama 236-8648, Japan. E-mail: [email protected] Accepted February 5, 2014 (received for review December 11, 2013) Journal of Oleo Science ISSN 1345-8957 print / ISSN 1347-3352 online http://www.jstage.jst.go.jp/browse/jos/ http://mc.manusriptcentral.com/jjocs

555 H. Saito and S. Ishikawa

for the nutritive value have been published22）, in particular, lipids）were dissected, while whole body of each juvenile fatty acid composition23, 24）. was sampled（except for stomach）. The ordinary muscle, In the present study, comprehensive analyses of lipid liver, and stomach contents were separately homogenized classes and fatty acid compositions of cultured and wild S. in a mixture of chloroform and methano（l 2:1, v/v）, and a schlegeli were conducted to examine the differences in portion of each homogenized sample was extracted ac- lipid classes and fatty acid profile in an effort to produce cording to the Folch procedure25）. Each crude lipid was good quality cultured fish. separated into classes on silicic acid column（s Merck and Co. Ltd., Kieselgel 60, 70-230 mesh）, and quantitative analysis of the li-pid constituents was performed using gravi- metric analysis of fractions collected from column chroma- 2 Material and methods tography4）. The first eluate（dichloromethane/n-hexane, 2.1 Materials 2:3, v/v）was collected as steryl ester, wax ester, and diacyl- The biological data of S. schlegeli are listed in Table 1. glyceryl ether fraction（s Table 2）. This was followed by The aquacultured S. schlegel（i samples 1, 2, and 3）were eluting the triacylglycerol（s TAG）with dichloromethane collected in October 2009 at“ Wakinosawa Fisheries Coop- and eluting the sterols with dichloromethane/ethe（r 35:1, v/ erative Association,” an aquaculture farm in Mutsu Ba（y 41° v）; eluting the diacylglycerols with dichloromethane/ether 09′N and 140°50′E）on Honshu Island in Japan. All cultured （9:1, v/v）; eluting the free fatty acids with dichlorometh- samples were raized in the aquaculture farm for one year ane/methano（l 9:1, v/v）; eluting the phosphatidylethanol- and six month（s from spring to autumn of the next year）. amine（PE）with dichloromethane/methano（l 1:5, v/v）; The juvenile and young sample（s Nos. 1 and 2）were cul- eluting other minor phospholipids with dichloromethane/ tured with the similar artificial feed（s Tables 2 and 3）. methano（l 1:20,v/v）; and eluting phosphatidylcholine（PC） From May to Jul（y 2 months）, samples 1 were fed a juvenile with dichloromethane/methano（l 1:50, v/v）4）. feed（Otohime A, Maruha Ltd., Japan）, while from July to Individual lipids from each lipid class, such as the phos- Decembe（r 6 months）, samples 2 were fed another feed pholipid class, were qualitatively identified with standards （EP-3 and EP-4, Maruha Ltd., Japan）. December to by comparing the Rf values using thin-layer chromatogra- October in the following yea（r 10 months）, the feeds for ph（y Merck & Co. Ltd., Kieselgel 60, thickness of 0.25 mm the samples 2 were changed to raw whole fish, such as for analysis）. All sample lipids were dried under argon at sardine（Sardinops melanostictus）and anchovy（Engrau- room temperature and stored at －40℃ under argon. lis japonica）, and the samples were fed during 10 months （sample 3）. 2.3 Preparation of methyl esters and gas-liquid chroma- In January 2010, wild S. schlegel（i samples 4）were col- tography（GLC）of esters lected near the coast of Fukaura in the Japan Se（a 40°45′N Individual components of TAG, PE, and PC fractions and 140°06′E）. After their biological data were measured, were converted to fatty acid methyl esters by direct trans- the specimens were immediately frozen at －40℃. esterification with methanol containing 1％ concentrated hydrochloric acid under reflux for 1.5 hr, as previously re- 2.2 Lipid extraction and analysis of lipid classes ported, to produce the fatty acid methyl esters4）. These From each adult and young individual of S. schlegeli, methyl esters were purified using silica gel column chroma- the muscle tissue（edible part）and live（r representative of tography by elution with dichloromethane/n-hexane（2/1, viscera）with stomach content（s influence of the prey v/v）.

Table 1 Locality of Capture and Biological Data of Sebastes schlegeli Hilgendorf.

556 J. Oleo Sci. 63, (6) 555-566 (2014) Lipid Classes and Fatty Acid Profile of Cultured and Wild Black Rockfish, Sebastes schlegeli The Lipid Contents and Classes of Sebastes schlegeli Hilgendorf.

Table 2 Table

557 J. Oleo Sci. 63, (6) 555-566 (2014) H. Saito and S. Ishikawa

The composition of the fatty acid methyl esters was de- 3 Results termined by gas-liquid chromatograph（y Table 3–6）. Analy- 3.1 Lipid content of S. schlegeli under two different condi- sis was performed on HP-5890（Hewlett Packard Co. Ltd., tions（cultured and wild） Yokogawa Electric Corporation, Tokyo, Japan）gas chro- The biological data of the S. schlegeli samples are listed matographs equipped with an Omegawax-250 fused silica in Table 1 with other relevant data. As shown in Table 2, capillary column（30 m×0.25 mm i. d.; 0.25 μm film, the muscle lipid content of the cultured adult sample Supelco Japan Co. Ltd., Tokyo, Japan）. The temperatures （sample No. 3, cultured adult; 0.6％ for muscle and 13.9％ of the injector, the detector, and the column were held at for liver）was similar to that of the wild adult sample 230, 240, and 215℃, respectively, and the split ratio was （sample No. 4, wild adult; 1.1％ for muscle and 12.5％ for 1:76. Helium was used as the carrier gas at a constant inlet liver）. On the other hand, higher levels of lipid content of rate of 0.7 mL/min. In the fatty acid compositions of phos- juvenile and young sample（s No. 1, juvenile; 4.1％ for phatidylethanolamine（PE）, low levels of dimethylacetals whole, and No. 2, young; 5.6％ for muscle and 25.0％ for （DMA）, such as DMA 18:0 and DMA 20:1, were included liver）were observed. （Tables 3–6）. The theoretical values of the fatty acid com- The lipid class composition of the S. schlegeli samples is positions were obtained by subtracting the DMA from the shown in Table 2. TAG（for muscle and liver; 63.4–77.5 and total fatty acid（s TFA）of PE4）. 54.5–65.1％ of total lipids, TL, for adult sample and 49.0％ Quantitation of individual components was performed by of TL and 75.1–80.0％ of TL for juvenile and young means of HP ChemStation System（A. 06 revision, Yokoga- samples）was the major component in all muscle and liver wa HP Co. Ltd., Tokyo, Japan）electronic integrators. lipids. As for other minor classes, noticeable levels of phospholipids, such as PE（for muscle and liver; 3.4–5.6 and 2.4 Preparation of 4,4-dimethyloxazoline derivatives 1.3–3.3％ for adult sample and 6.6 and 1.3–3.8％ for juve- （DMOX）and analysis of DMOX by gas chromatogra- nile and young samples）and PC（for muscle and liver; 8.8– phy - mass spectrometry（GC/MS） 14.2 and 2.6–6.4％ for adult sample and 5.2 and 1.1–8.0％ For further identification of fatty acids with GC/MS, the for juvenile and young samples）were observed, while steryl DMOX derivatives were prepared by adding an excess ester（s 12.2–12.4％）and free fatty acid（s 8.1–9.1％）were amount of 2-amino-2-methyl propanol to a small amount of found as minor components in the adult liver lipids. All S. fatty acid methyl esters in a test tube under an argon at- schlegeli muscle lipids mainly contained glycerol deriva- mosphere. The mixture was heated at 180℃ for 18 hr4）. tive（s TAG, diacylglycerols, PE, and PC）and the total pro- Analysis of the DMOX derivatives was performed by a portion of these derivatives reached over 80％. In whole HP G1800C GCD Series I（I Hewlett Packard Co., Yokogawa juvenile sample（s No. 1）containing skins and viscera, Electric Corporation, Tokyo, Japan）GC/MS equipped with medium levels of TAG with small levels of sterols, and free the same capillary used for determining the respective fatty acids were found. fatty acids with the HP WS（HP Kayak XA, G1701BA version, PC workstations）. The temperatures of the injec- 3.2 Fatty acid composition in TAG depot lipids of S. tor, the detector, and the column were held at 230, 240, schlegeli and 215℃, respectively. The split ratio was 1:76, and the The major fatty acids in the depot TAG of three S. ionization voltage was 70 eV. Helium was used as the schlegeli stage（s juvenile, young and adult）are shown in carrier gas at a constant inlet rate of 0.7 mL/min. The fatty Tables 3–6. acid methyl esters were identified by comparing the methyl The fatty acids in the TAG of the whole body of juvenile ester and DMOX derivative mass spectral data obtained by sample（s No. 1）with their feeds are shown in Tables 3 and GC/MS. The DMOX derivatives were identified by compar- 4. Nine dominant fatty acid（s more than about 3％ of total ing the mass spectral data obtained with authentic fatty acids: TFA）in the feed of the juvenile sample（Table samples. 3）were found; 14:0, 16:0 and 18:0 as saturated fatty acids, 16:1n-7, 18:1n-7 and 18:1n-9 as monounsaturated fatty 2.5 Statistical analyses acid（s MUFA）, 18:2n-6（linoleic acid, 4.9-5.3％）as n-6 poly- More than two experimental replication（s n＝2–4 in unsaturated fatty acid（s PUFA）, 20:5n-3（EPA）and 22:6n-3 Table 2）were made for lipid classes and（n＝2–10 in Tables （DHA）as n-3 PUFA with noticeable level（s more than 3–6）for fatty acid analysis. Significant mean differences about 1％ of TFA）of four fatty acids; 20:1n-9, 16:2n-4, were determined using a one-way analysis of variance 18:3n-3, and 22:5n-3（docosapentaenoic acid）. The same （ANOVA）. Tukey’s multiple procedure was used to nine dominant fatty acids in the whole body lipid（s No. 1 compare the differences among mean values. Differences for cultured juvenile sample, Table 4）were also found; were regarded as significance level of p＜0.05. 14:0, 16:0, 18:0, 16:1n-7, 18:1n-7, 18:1n-9, 18:2n-6（5.0％）, EPA, and DHA with noticeable levels of the same four fatty acids; 20:1n-9, 16:2n-4, 18:3n-3, and 22:5n-3.

558 J. Oleo Sci. 63, (6) 555-566 (2014) Lipid Classes and Fatty Acid Profile of Cultured and Wild Black Rockfish, Sebastes schlegeli

Table 3 Fatty ‌ acid composition of the stomach contents of cultured young Sebastes schlegeli and their feedstuffs examineda.

559 J. Oleo Sci. 63, (6) 555-566 (2014) H. Saito and S. Ishikawa

Table 4 Fatty acid composition of cultured juvenile and young Sebastes schlegeli examineda.

The fatty acids in the stomach contents of the young nant fatty acids in the stomach contents TAG（No. 2）were sample（s No. 2）with their feeds are shown in Table 3. found; 14:0, 16:0, 18:0, 16:1n-7, 18:1n-7, 18:1n-9, 18:2n-6 Similar to the major fatty acids in feed of juvenile sample （6.6％）, EPA, and DHA with noticeable levels of ﬁve fatty No. 1, nine dominant fatty acids in the feed crude lipids acids; 20:1n-9, 22:1n-11, 16:2n-4, 18:3n-3, and 22:5n-3, were found; 14:0, 16:0, 18:0, 16:1n-7, 18:1n-7, 18:1n-9, very similar to those in the feed crude lipids for juvenile 18:2n-6（7.0–7.6％）, EPA, and DHA with noticeable levels and young sample（s Table 3）. of six fatty acids; 20:1n-9, 22:1n-11, 16:2n-4, 20:4n-6（ara- The fatty acids in the TAG of the muscle and liver of chidonic acid）, 18:3n-3, and 22:5n-3. The same nine domi- young sample（s No. 2）are shown in Table 4. The same nine

560 J. Oleo Sci. 63, (6) 555-566 (2014) Lipid Classes and Fatty Acid Profile of Cultured and Wild Black Rockfish, Sebastes schlegeli

Table 5 Fatty acid composition of cultured adult Sebastes schlegeli and its feedstuff examineda.

dominant fatty acids in both the muscle and liver TAG（for of three fatty acid（s for only muscle of No. 2）; 20:1n-9, cultured sample No. 2）were found; 14:0, 16:0, 18:0, 16:1n- 18:3n-3, and 22:5n-3, similar to those in juvenile samples 7, 18:1n-7, 18:1n-9, 18:2n-6（4.0％ for the liver, 5.9％ for No. 1. the muscle of No. 2）, EPA, and DHA with noticeable levels The fatty acids in the TAG of the muscles, liver, and

561 J. Oleo Sci. 63, (6) 555-566 (2014) H. Saito and S. Ishikawa

Table 6 Fatty acid composition of wild adult Sebastes schlegeli and its stomach contents examineda.

stomach contents of the adult samples are shown in Tables 4）, 22:1n-11（No. 4）, 16:2n-4（No. 4）, 18:2n-6, 20:4n-6（No. 5 and 6. Both in cultured and wild samples, slightly differ- 3）, and 22:5n-3. ent dominant fatty acids in the TAG of feed crude lipid（s for Slightly different from the fatty acid proﬁles of feed（cul- cultured sample No. 3 in Table 5）and stomach contents tured）and stomach content（s wild）lipids, similar seven TAG（for wild sample No. 4 in Table 6）were found; 14:0, dominant fatty acids in the liver lipids of both the cultured 16:0, 18:0, 16:1n-7, 18:1n-9, 20:1n-11（No. 3）, 22:1n-11 and wild sample（s No. 3 for cultured sample and No. 4 for （No. 3）, EPA, and DHA with noticeable levels of several wild sample, Tables 5 and 6）were found; 16:0, 18:0, 16:1n- fatty acids; 15:0（No. 4）, 17:0（No. 4）, 18:1n-7, 20:1n-9（No. 7, 18:1n-7, 18:1n-9, EPA, and DHA with noticeable levels

562 J. Oleo Sci. 63, (6) 555-566 (2014) Lipid Classes and Fatty Acid Profile of Cultured and Wild Black Rockfish, Sebastes schlegeli

of several fatty acids; 14:0, 20:1n-9, 20:1n-11, 22:1n-11, fatty acids of phospholipids between cultured and wild 16:2n-4（No. 4）, 18:2n-6（No. 4）, 20:4n-6（No. 4）, and samples were very similar to each other. Similar to the fatty 22:5n-3（No. 4）. The same nine dominant fatty acids in the acid profiles in TAG of both cultured and wild adult muscle lipids of both the cultured and wild samples were sample（s Nos. 3 and 4）, those in the phospholipids of both found; 14:0, 16:0, 18:0, 16:1n-7, 18:1n-7, 18:1n-9, 20:1n- the samples were very similar to each other. 11, 22:1n-11（No. 3）, EPA, and DHA with noticeable levels of seven fatty acids; 20:1n-9, 22:1n-11（No. 4）, 16:2n-4（No. 4）, 18:4n-1, 18:2n-6, 20:4n-6, and 22:5n-3. In both the cases of liver and muscle of S. schlegeli, the major fatty 4 Discussion acids between cultured and wild samples were very similar 4.1 Lipid content of S. schlegeli under two different condi- to each other. tions（cultured and wild） The muscle lipid contents in both cultured and wild 3.3 Fatty acid composition in tissue phospholipids in S. adult S. schlegeli were markedly lower than those in the schlegeli liver lipids, while high levels of whole lipids in the juvenile The major fatty acids of the phospholipid（s PE and PC） and muscle lipids in the young samples were found（Table are also shown in Tables 3–6. In many case, the fatty acid 2）. This implies that adult S. schlegeli mostly accumulate composition in the muscle and stomach content PE includ- their lipids in the liver, similar to those in some demersal ed low levels of DMA, such as DMA 16:0, DMA 18:0, and fish species such as sea bream and flounder23）. Higher DMA 18:1（Tables 3–6）. levels of lipid content of juvenile and young samples might The fatty acids in the stomach content polar lipids of the be influenced by higher lipid levels in their feed（s 12.7％ young sample（s No. 2）are shown in Table 3. Eight domi- for feed of No. 1 and 7.8％ for feed of No. 2）, compared nant fatty acids in the stomach contents PE and PC were with the lower lipid levels in the adult feed（s 2.9％ for feed found; 16:0, 18:0, 16:1n-7, 18:1n-7, 18:1n-9, 18:2n-6（8.0％ of No. 3 and 1.5％ for stomach contents of No. 4）. Al- for PE and 5.3％ for PC）, EPA, and DHA with noticeable though the difference of muscle and liver lipid contents levels of four fatty acids; 14:0, 20:1n-9（for PE）, 20:4n-6, was great, TAG was the major component in both the and 22:5n-3. The major fatty acids in the stomach content muscle and liver lipids, with low levels of sterols, PE, and polar lipids of young samples were similar to those in the PC. Accordingly, similar major lipid class compositions of crude lipids of its feed（Table 3）. the muscle and liver lipids in both the cultured and wild The fatty acids in the PE and PC of the whole body of ju- samples were found. As for differences in the minor venile sample（s No. 1）are shown in Table 4. Seven major classes, noticeable levels of phospholipids with sterols fatty acids in the PE and PC of all samples were found; found only in the muscle lipid were the same as the tissue 16:0, 18:0, 18:1n-7, 18:1n-9, 18:2n-6（3.2％ for PE and lipids of other fish species23）. This suggests the importance 2.7％ for PC）, EPA, and DHA with noticeable levels of four of phospholipids in muscles as membrane lipids. In general, fatty acids; 16:1n-7, 16:2n-4, 20:4n-6, and 22:5n-3. The the proportions of phospholipid in tissue TL are constant fatty acids in the PE and PC of the liver and muscle of in all animals because they are important as cell membrane young sample（s No. 2）are also shown in Table 4. Eight lipids26）. The mean phospholipid contents in tissues of all major fatty acids in the PE and PC of all muscle and liver marine organisms can be less than 1％ of their tissue samples were found; 16:0, 18:0, 16:1n-7, 18:1n-7, 18:1n-9, weight26）. Compared with the slightly higher TAG levels in 18:2n-6（4.3–5.2％ for PE and 4.0–4.5％ for PC）, EPA, and the wild muscle sample（s 77.5％）, the lower level of depot DHA with noticeable levels of four fatty acids; 14:0, 20:1n- TAG（63.4％）with higher phospholipid level（s 5.6％ for PE 9, 20:4n-6, and 22:5n-3. Similar to the fatty acid profiles in and 14.2％ for PC）in cultured muscle sample（s No. 3） TAG of juvenile and young（immature）samples, those in might be refrected by the lower lipid content in the cul- the phospholipids of both the sample（s Nos. 1 and 2）were tured sample（s 0.6％）. Slightly higher levels of free fatty similar to each other. acids in the adult liver lipids and juvenile samples were The fatty acids in the phospholipid（s PE and PC）of the probably influenced by digestive enzymes in the internal muscles, liver, and stomach contents of the adult samples organs, such as liver4, 27）. Similar to the lipid class profiles of are shown in Tables 5 and 6. Both in cultured and wild other marine fishes, that of S. schlegeli consists of glycerol samples, similar seven dominant fatty acids in the muscle derivatives. These findings are the lipid characteristics of S. and liver phospholipids were found（Tables 5 and 6）; 16:0, schlegeli as a typical Sebastes fish species. 18:0, 18:1n-7（for PE）, 18:1n-9, 20:4n-6, EPA, and DHA （31.3–39.1％ for livers and 38.3–43.5％ for muscles）with 4.2 Fatty acid composition in TAG depot lipids of juvenile noticeable levels of three fatty acids; 16:1n-7, 22:5n-6, and and young S. schlegeli: relationship with dietary lipids 22:5n-3. In particular, high levels of DHA were observed in It is generally known that there are significant levels of both cultured and wild muscle phospholipids. All major 18:2n-6 in freshwater and cultured fishes, while low or

563 J. Oleo Sci. 63, (6) 555-566 (2014) H. Saito and S. Ishikawa

trace 18:2n-6 levels are present in wild marine fish lipids4, 28）. 4.4 Fatty acid composition in polar tissue lipids of juvenile The lipids of both the juvenile and young S. schlegeli and young S. schlegeli sample（s Nos. 1 and 2, Table 4）contained the same major Although juvenile and young S. schlegeli assimilated fatty acids. In particular, the TAG of both juvenile and intact dietary lipids as they were from the artificial feeds, young S. schlegeli contained markedly high levels of this species presumably accumulated n-3 PUFA for their 18:2n-6（4.0–5.9％ in Table 4）in spite of their being marine tissue phospholipids, because higher levels of long-chain fish species. The same trends were found in the stomach PUFA in the PE and PC were observed, compared with contents of young S. schlegel（i 18:2n-6: 6.6％, in Table 3） their depot TAG and the dietary lipids. For example, the and artificial feeds for both the juvenile（s 4.9–5.3％, crude higher levels of DHA in the juvenile phospholipid（s 29.1％ lipids of Feed 1-1 and Feed 1-2 in Table 3）and young fishes for PE and 20.6％ for PC in Table 4）were found, compared （7.0–7.6％, crude lipids of Feed 2-1 and Feed 2-2 in Table with those in the depot TAG（9.7％ in Table 4）and the feed 3）. This finding indicates that the cultured fishes were in- （9.4–13.7％ in Table 3）. In the case of the young sample fluenced by their feed, because both the juvenile and （No. 2）, the higher DHA level（s 16.7–24.5％ for PE and young S. schlegeli were fed by artificial feed（s dry pellets）, 13.7–18.0％ for PC in Table 4）in their phospholipids were which included high levels of plant oils, such as soybean oil also observed, compared with those in their TAG and the rich in 18:2n-6, while cultured adult fishes were fed by feed（s 3.3–6.7％ in Table 4 and 11.4–13.7％ in Table 3）. natural raw fish such as sardine（Sardinops melanostic- These trends are similar to those in other marine fish tus）and Japanese anchovy（Engraulis japonicus）. The species4, 27）. All these findings for the polar lipids of juvenile same high levels of 18:2n-6 were also observed in other cul- and young S. schlegeli imply that the TAG of the samples tured fishe（s for freshwater fish28, 29）; for marine fish4, 5, 7, 10））. was simply influenced by the dietary lipids; however, the higher levels of n-3 PUFA, such as DHA, in polar lipids 4.3 Fatty acid composition in TAG depot lipids of adult S. were observed. This suggests presence of the accumulation schlegeli mechanisms of n-3 PUFA in its muscle tissue phospholip- Although the kinds of dominant fatty acids in the muscle ids, similar to that in highly migratory fishes. All these and liver lipids were the same in both the cultured and wild marine fishes have a trend for accumulating their essential adult S. schlegel（i Tables 5 and 6）and all major fatty acids PUFA, such as DHA4, 27）. between muscle and liver TAG were very similar, the levels of these acids were slightly different. For example, mean 4.5 High levels of PUFA in adult S. schlegeli polar lipids total PUFA levels in the muscle TAG of samples Nos. 3 and and accumulation of DHA in S. schlegeli tissue levels 4（35.2 and 31.6％ in Tables 5 and 6）were higher than Although the kinds of major fatty acids between PE and were those in the liver TAG（9.9 and 18.7％ in Tables 5 and PC of all samples were the same, similar to that of the 6）. This is primarily caused by differences in DHA levels depot TAG, as mentioned above, the levels of some fatty （11.9–19.7％ for the muscle TAG vs. 3.2–5.2％ for liver acids in the adult tissue phospholipids were different from TAG in Tables 5 and 6）. Both the cultured and wild adult the dietary lipids. For example, the total n-3 PUFA levels sample（s Nos. 3 and 4）contained low levels of 18:2n-6 with of polar tissue lipids in both adult sample（s 42.3–51.4％ for high levels of DHA in the muscle and liver lipid（s Tables 5 Nos. 3 and 4 in Tables 5 and 6）were markedly higher than and 6）, different from the high 18:2n-6 levels in the TAG of were those in the juvenile and young S. schlegel（i 25.1– juvenile and young S. schlegel（i Nos. 1 and 2 in Table 3）. 39.1％ for for Nos. 1 and 2 in Table 4）. High n-3 PUFA Similar to the influence of feeds on the lipids of juvenile levels in the lipids of adult S. schlegeli suggest a concen- and young S. schlegeli, these phenomena indicate the in- tration of n-3 PUFA in the S. schlegeli tissue phospholip- fluence of prey or dietary lipids, such as sardine and ids, in comparison with the lower levels in the total n-3 anchovy, on the adult samples. This is confirmed because PUFA of the adult S. schlegeli dietary polar lipid（s 35.2– trace levels of 18:2n-6 were also observed with compara- 37.3％ for stomach content polar lipids and 30.3–38.0％ for tively high levels of DHA in the lipids of stomach contents feed total crude lipids in Tables 5 and 6）. Similarly, the （partly digested small horse mackerels）in wild adult DHA levels in the tissue polar lipids were higher than were samples No. 4（Table 6）and the feed of cultured adult those in the stomach contents and the feed lipid（s Tables 5 samples No. 3（Table 5）. With the influence of the prey and 6）. In particular, markedly high DHA level（s 38.3– lipids, these findings indicate that S. schlegeli concentrat- 40.2％ for cultured and 40.1–43.5％ for wild）were found in ed important n-3 PUFA in its muscle, while depot MUFA the adult muscle lipids. This means that adult S. schlegeli were accumulated in the live（r Tables 5 and 6）, similar to actively concentrate important n-3 PUFA in muscle, while other fish species4, 27）. liver lipids are directly influenced by the prey or dietary lipids, similar to the juvenile and young samples. With the influence of the prey lipids, the high n-3 PUFA levels in the phospholipids suggest the importance of long-chain n-3

564 J. Oleo Sci. 63, (6) 555-566 (2014) Lipid Classes and Fatty Acid Profile of Cultured and Wild Black Rockfish, Sebastes schlegeli

PUFA for S. schlegeli. In general, DHA is required as es- 6） Álvarez, V.; Medina, I.; Prego, R.; Aubourg, S. P. Lipid sential in plasma membrane lipids of common marine and mineral distribution in different zones of farmed fishes30, 31）, and a similar phenomenon is observed in the ad wild blackspot seabream（Pagellus bogaraveo）. case of S. schlegeli phospholipids. Markedly high DHA Eur. J. Lipid Sci. Technol. 111, 957-966（2009）. levels in adult S. schlegeli were similar to those in the 7） Grigorakis, K.; Alexis, M. N.; Taylor, K. D. A.; Hole, M. highly migratory fishes, such as tuna species1, 3, 4, 27）. The Comparison of cultured githead sea bream（Sparus lipid characteristics of the cultured adult S. schlegeli aurata）; composition, appearance and seasonal varia- samples were the same as those of the wild ones. There- tion. Int. J. Food Sci. Technol. 37, 477-484（2002）. fore, their nutritional values of fatty acids are considered 8） Van Anholt, R. D.; Spanings, F. A. T.; Koven, W. M.; the same. In general, cultured fishes have higher levels of Nixon, O.; Wendelaar Bonga, S. E. Arachidonic acid lipid contents and lower ratio of n-3 PUFA32）, and this is reduces the stress response of gilthead seabream Spa- similar to the results of Crawford’s report33） that domestic rus aurata L. J. Exp. Biol. 207, 3419-3430（2004）. animals contain more fat and less essential fatty acids than 9） Valente, L. M. P.; Cornet, J.; Donnay-Moreno, C.; Gouy- do wild land animals. However, in this case, the farm gou, J. P.; Bergé, J. P.; Bacelar, M.; Escórcio, C.; Rocha, changed from artificial feed to fresh, small wild fishes as its E.; Malhäo, F.; Cardinal, M. Quality differences of gilt- feeds about 10 months before shipping adult S. schlegeli head sea bream from distinct production systems in to market. Presumably, this is the best way to formulate a Southern Europe: intensive, integrated, semi-intensive first-rate, healthful marine food. or extensive systems. Food Contr. 22, 708-717（2011）. 10） Benedito-Palos, L.; Calduch-Giner, J. A.; Ballester-Loz- ano, G. F.; Péres-Sánchez, J. Ef-fect of ration size on fillet fatty acid composition, phospholipid allostasis Acknowledgments and mRNA expression patterns of lipid regulatory We are grateful to Wakinosawa-mura Fisheries Coopera- genes in gilthead sea bream（Sparus aurata）. British tive Association, Mutsu, and Shinfukaura-machi Fisheries J. Nutr. 102, 1-13（2012）. Cooperative Association, Fukaura-machi, for generously 11） Estévez, A.; Izhikawa, M.; Kanazawa, A. Effect of ara- donating the samples that made this work possible. The chidonic acid on pigmentation and fatty acid composi- authors also thank Ms. Noriko Tsutsui and Mr. Akihito Ta- tion of Japanese flounder, Paralychthys olivaceous kashima for their skilled technical assistance. H. S. per- （Temmink and Schlegel）. Aquac. 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