[Retracted] Anti­carcinogenic activity of anandamide on human glioma in vitro and in vivo.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the scratch-wound data shown in Fig. 3A were strikingly similar to data appearing in different form in another article by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere prior to its submission to Molecular Medicine Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Molecular Medicine Reports 13: 1558­1662, 2016; DOI: 10.3892/mmr.2015.4721].

[Microplastics in the stomach and intestine of pelagic squid: A case study of Dosidicus gigas in open sea of Peru]. / å¤§æ´‹æ€§å¤´è¶³ç±»èƒƒå’Œè‚ é“ä¸­çš„å¾®å¡‘æ–™­­ä»¥ç§˜é²å¤–海茎柔鱼为例.

Microplastic (MP) ingestion by marine animals has been well documented, but less being known about pelagic squid. Jumbo squid Dosidicus gigas supports the world's largest cephalopod fishery and plays an important ecological role in the Eastern Pacific Ocean. In this study, D. gigas taken from the open sea of the Peruvian Exclusive Economic Zone were selected as research objects. We estimated the abundance and characteristics of MPs in the stomach and intestine of D. gigas and investigated the differences between tissues and sexes. Similar abundance and characteristics of MPs were observed in the same tissue of females and males. However, the stomach had a higher abundance of MPs with larger size than the intestine, while the MP abundance by stomach wet weight was lower than that of the intestine. The MPs were predominantly fiber-shaped, with blue or black color. The most frequent polymers were high-density cellophane and polyacrylic acid. These polymers could sink into deeper sea layers and were available for D. gigas living there during the daytime. Our findings revealed the distribution pattern of MPs in the waters of the Peruvian fishing ground. This study could improve our understanding of the MP contamination level in pelagic squid, and have implications for evaluating the ecological effects of MP on cephalopods.

[Statolith microstructure and growth characteristics of Sthenoeuthis oualaniensis in the northwest Indian Ocean]. / 西北印度洋海域鸢乌贼耳石微结构及生长特性.

Statolith is one of the most important hard tissues to study the age, growth, population structure and life history of cephalopods. In order to stuty statolith microstructure and growth characteristics of Sthenoeuthis oualaniensis in the northwest Indian Ocean, 1009 samples were collected by Chinese light falling-net fishery fleets during investigation and production in the northwest Indian Ocean from February to May of 2019. Total statolith length (TSL), lateral dome length (LDL), wing length (WL) and maximum width (MW) were taken as the indicators of morphological feature of the statolith, combined with the age data, the statolith microstructure and growth characteristics of S. oualaniensis were studied. The results showed that the statolith microstructure could be divided into postnuclear zone, dark zone and peripheral zone according to the width of growth increment. The analysis of covariance showed that there was no growth difference of TSL, LDL, WL and MW between different sexes. The relationships between TSL, WL, MW and age were best described by the power functions, while the relationship between LDL and age was best described by the linear function. In general, with the increase of age, the instantaneous relative growth rate and absolute growth rate of TSL, WL, LDL and MW decreased, and 140-180 d may be the age of sexual maturity for this squid.

[Age and growth characteristic of Sepia officinalis in the West Africa based on cuttlebones.] / åŸºäºŽå† å£³çš„è¥¿éžä¹Œè´¼æ—¥é¾„ä¸Žç”Ÿé•¿ç‰¹æ€§.

Common cuttlefish is mainly distributed in the eastern North Atlantic and the coastal waters of Africa, which is an important fishing target for trawl fisheries and the most important commercial species in the Atlantic sepia family. In this study, based on the cuttlefish samples collected from the west Africa coast in July-August 2015, we measured the outer morphological parameters of 283 cuttlebones. Combined with the age information of cuttlebones, we examined the growth characteristics of cuttlefish of different genders. The results showed that there were significant differences in body length and body weight between different genders. The dominant age group of female and male was both 80-100 days. Among the fitting functions of the outer shape of cuttlebone and the age, the logistic function was the best one. The females' maximum likelihood estimates of the outer morphological parameters of cuttlebone were larger than that of males. The absolute and instantaneous relative growth rates of the cuttlebone length and width of male and female cuttlefish peaked at 110-120 days and 100-110 days, respectively. The age of males and females at first sexual maturity was 111 days and 104 days, respectively. The growth difference between genders might be related to environment.

[Factors influencing beak morphology of Sthenoteuthis oualaniensis in the northwest Indian Ocean.] / è¥¿åŒ—å°åº¦æ´‹é¸¢ä¹Œè´¼è§’è´¨é¢šå¤–å½¢å˜åŒ–çš„å½±å“å› ç´ .

With 1009 Sthenoteuthis oualaniensis samples collected by Chinese light falling-net fishery during February to May in the northwest Indian Ocean, we analyzed the influencing factors of the morphology change of the beak. There were significant differences in the morphologic growth between genders, different gonad maturity stages, and different mantle length. The increment of characteristic parameters growth peaked in the mantle length between 201 and 250 mm, and in the Ⅱ and Ⅲ stages of gonad maturity for females and males, respectively. There was no significant difference in the ratio of morphometric parameters to crest length (CL) between the genders, diffe-rent gonad maturity stages, and different mantle length, except for the ratio of upper hood length to upper crest length (UWL/UCL) and lower hood length to lower crest length (LHL/LCL). The ratio of each characteristic parameter to CL was nearly stable with the change of sex, gonad maturity and mantle length, suggesting consistent growth of each dome of beak. Our results suggested the mantle length of 201 mm to 250 mm seemed to be the threshold for the morphologic growth of beak on the body size, while the gonad maturity of Ⅱ and Ⅲ stages seemed to be the threshold for the morphologic growth of beak on the gonad maturity.

Differences in lipid composition of Bigeye tuna (Thunnus obesus) during storage at 0 °C and 4 °C.

This study aimed to investigate the lipid oxidation and distribution in Bigeye tuna stored at 0 °C and 4 °C for 6 days. Tuna were evaluated by determining the peroxide value (POV), acid value (AV), anisidine value (AnV), polyene index, fluorescence ratio (FR), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) content, and major glycerophospholipid molecular species. The value of lipid oxidation indexes (POV, AV, AnV, FR, PC, PE and PI) increased as the storage time increased. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) results indicated that the major types of lipids included diacylglycerol (DAG), monoacylglycerol (MAG), phospholipid (PL), and triacylglycerol (TAG). At least 136 PC and 64 PE molecular species were identified in Bigeye tuna. The results of the confocal laser scanning microscope analysis indicated the distribution of TAG and PL particles. In addition, principal component analysis showed that the contents of PI and TAG were positively correlated with PC, polyene index and lipid content but negatively correlated with PI, POV, FR, AOV, AnV, MAG, and DAG, which might be explained by distinguishing the lipid parameters affecting lipid oxidation. Therefore, this study may provide a novel method to evaluate lipid changes and contribute to the balanced nutritional value of aquatic foods during cold storage.

Applications of Non-invasive and Novel Methods of Low-Field Nuclear Magnetic Resonance and Magnetic Resonance Imaging in Aquatic Products.

Aquatic products, such as fish, are popular throughout the world due to their satisfying flavor characteristics as well as rich animal nutrition, and they provide high-value food therapy, but they are easily oxidized and spoiled. It is necessary to detect aquatic products through rapid and accurate technology. Low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) have been widely used in the aquatic product industry due to their sensitivity, fast analysis, non-destructive nature and low cost. The applications of LF-NMR in the measurement of aquatic product quality and nutrients (water, fat, and protein) are summarized in this paper. Applications in aquatic products have been shown to depend on deep processing, storage and authentication. This review discusses the application of MRI technology in the quality control of aquatic products. Therefore, this review will guide the application of the aquatic products industry and aims to supply the reader with both the theory of the method and practical applications of the method for use as a rapid and non-destructive technology in scientific research and the industrial industry.

Trophic niche and gut microbiota of Dosidicus gigas in the eastern equatorial Pacific Ocean.

Understanding the adaptation of important marine species to environmental changes is critical for evaluating the effects of fisheries and climate change on marine services. The jumbo squid, Dosidicus gigas, is a keystone species in the eastern Pacific, which plays an intermediate role in the marine food web. Better understanding of their responses to climate change would be a big step to understand their population dynamics. In this study, stable isotope and high-throughput 16S rRNA sequencing were used to compare the variation of trophic niche, gut length, and gut microbiota of D. gigas in the eastern equatorial water during normal and El Niño periods. The results showed a significant variation in δ13C values for D. gigas in different periods, indicating differences in their food sources. The main phylum-level gut microbiome included Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Proteobacteria, and Tenericutes. There was no significant difference in the gut microbial composition during normal and El Niño periods, but differences in gut microbial diversity and relative abundance of some phyla bacteria. El Niño events could decrease the trophic niche breadth of D. gigas, and positively impact gut length and gut microbial diversity and richness. Firmicutes, Bacteroidetes, Spirochaetes, WPS-2, and Kiritimatiellaeota had a significant increase in the gut microbiota of D. gigas combined with a more concentrated intraspecific rank of distance during El Niño, suggesting that the changes of habitat and food sources caused by El Niño events could limit the distribution range of D. gigas. D. gigas might change their digestive system to improve the digestive and absorption capacity and enhance their immunocompetence. Such a climate-driven alteration might help D. gigas rapidly adapt to the changes of environmental conditions and food resources under El Niño.

Blending strategies for wine color modification â : Color improvement by blending wines of different phenolic profiles testified under extreme oxygen exposures.

Limited oxygenation and over-oxidation experiments were designed to compare the phenolic and chromatic characters of base wines Cabernet Franc (CF), Cabernet Sauvignon (CS), and their counterparts that blended with modifier wines Marselan (MA) and Petit Verdot (PV). In both limited oxygenation and over-oxidation conditions, all blend wines generally contained higher C*ab, a* and Red%, and lower hab, b* and Yellow% than their base wine counterparts, because MA contributed flavonols (copigments) and anthocyanins, and PV contributed flavanols (anthocyanin derived pigments precursors). Chromatic changes that can be perceived by human eye (ΔE*ab) in CF based blend wines were more obvious than that of CS based blend wines, which indicate that base wine with lower phenolic concentrations and weak phenolic profiles (CF) might be more prone to be chromatically modified than base wine with higher phenolic concentrations and distinct phenolic profiles (CS). Chemical influences of different blending strategies on anthocyanin derivatives' formations were depending on phenolic profiles of the modifier wines and base wines, and also on the oxygen exposure. The results suggest that the chromatic improvement of base wines could be realized by blending modifier wines under different oxygen exposures.

[Beak morphological and growth characteristic of Sthenoteuthis oualaniensis in the northwest Indian Ocean in winter and spring]. / 冬春季西北印度洋鸢乌贼角质颚外部形态及生长特性.

Beak is one of the most important hard tissues of cephalopods, and thus is widely used in the study of cephalopod fisheries ecology and fishery resource assessment. With 1009 Sthenoteuthis oualaniensis samples collected by Chinese light falling-net fishery during February to May in the northwest Indian Ocean, we examined the morphologic and growth characteristics of beak. Results of the principal component analysis showed that the upper hood length (UHL), the upper crest length (UCL), the upper lateral wall length (ULWL), the lower crest length (LCL), the lower wing length (LWL) and the lower lateral wall length (LLWL) could be used as the morphological cha-racteristic parameters to examine the morphological changes of the beak. Results of the analysis of covariance (ANCOVA) showed that there were significant differences in the relationships between all of the morphological characteristic parameters and mantel length (ML) for males and females except UCL. There were significant differences in the relationships between all of the morphological characteristic parameters and body weight (BW) for males and females. The relationships between LCL, UCL and ML were optimally described by the linear functions. Power functions were best for UHL, LWL and linear functions were best for ULWL, LLWL for females. The relationships between ULWL and ML were optimally described by power functions, while the logarithm functions were best for UHL, LLWL and LWL for males. The relationships between all of the morphological characteristic parameters and BW were optimally described by the power functions for females, while the logarithm functions for males except the power function for ULWL. Our results provided scientific basis for the research of the fisheries ecology and stock assessment for S. oualaniensis.

[Beak morphological growth characteristic of Gonatopsis borealis in the Northwestern Pacific Ocean]. / 西北太平洋北方拟黵乌贼角质颚外部形态生长特性.

Beak is one of the most hard tissues in cephalopods, which is important in the study of fishery ecology. We analyzed the morphological growth characteristics of 268 beaks of Gonatopsis borealis collected in the Northwest Pacific Ocean from September to November of 2018 by Chinese jigging fishing fleets. Results from the principal component analysis showed that the upper hood length (UHL), upper crest length (UCL), upper rostrum length (URL), lower hood length (LHL), lower crest length (LCL) and lower rostrum length (LRL) could be used as the morphological characteristic parameters to study the morphological growth of beak. Results from the analysis of covariance (ANCOVA) showed that there was no significant difference both in the relationships between the morphological characteristic parameters versus mantle length (ML) or body weight (BW) for males and females. The relationships between ML and UHL, LHL were best described by power functions but by logarithm function for UCL, URL, LCL, and linear function for LRL respectively. The relationships between BW and UHL, UCL, URL, LCL, LRL were best described by logarithm functions but power function for LHL based on the result of the Akaike's information criterion. The results of growth models for the morphological parameters in this study provided scientific basis for the stock assessment in further research.

[Element composition in the statoliths of Sthenoteuthis oualaniensis squid in Xisha islands waters of South China Sea]. / ä¸­å›½å—æµ·è¥¿æ²™ç¾¤å²›æµ·åŸŸé¸¢ä¹Œè´¼è€³çŸ³å ƒç´ ç»„æˆ.

Sthenoteuthis oualaniensis is the most important cephalopods fishery resource of the South China Sea, which supported the falling-net fishery of Guangdong, Guangxi and Hainan Provinces of China. Understanding the fisheries biology is essential for sustainable exploitation and management of this squid. Statolith is one of the most important hard tissues of cephalopods which were widely used in the research of fisheries biology and ecology. Elements of 20 statoliths of S. oualaniensis collected in the Xisha islands waters of South China Sea during May to August by the falling-net fishery of 2017 were analyzed with Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for different sexes, different hatching groups, and history stages. The results showed that the statolith of the S. oualaniensis contained 55 elements, with calcium (Ca), strontium (Sr), sodium (Na), phosphorus (P), silicon (Si),magnesium (Mg), potassium (K), iron (Fe), barium (Ba) and boron (B) being the top ten abundant elements. The analysis of variance (ANOVA) showed that there was no significant difference in all element distributions between sexes for the most abundant ten elements. Significant differences existed in the contents of Si, Sr, Mg, Na and K but no significant difference was found in the contents of Ca, P, B, Fe and B between different hatching groups. There were significant differences in the contents of Sr, Na, P, K, Si, Mg, B and Ba, but no significant difference in the contents of Ca and Fe in the statoliths among different growth zones. Our results suggested that Sr, Na, K and Mg were probably the best four elements for life history reconstruction and examining population structure of the S. oualaniensis.

Apigenin inhibits glioma cell growth through promoting microRNA-16 and suppression of BCL-2 and nuclear factor-κB/MMP­9.

The present study aimed to investigate the effect of apigenin on glioma cells and to explore its potential mechanism. U87 human glioma cells treated with apigenin were used in the current study. Cell Counting Kit­8 solution and Annexin V-fluorescein isothiocyanate/propidium iodide Apoptosis Detection kit were used to analyze the effect of apigenin on U87 cell viability and apoptotic cell death. Reverse transcription­quantitative polymerase chain reaction analysis was also used to determine microRNA­16 (miR­16) and MMP­9 gene expression levels. Nuclear factor­κB (NF­κB) and B­cell CLL/lymphoma 2 (BCL2) protein expression levels were determined using western blot analysis. An anti­miR­16 plasmid was constructed and transfected into U87 cells. The current study demonstrated that apigenin significantly decreased cell viability and induced apoptotic cell death of U87 cells in a dose­dependent manner. Additionally, it was demonstrated that apigenin significantly increased miR­16 levels, suppressed BCL2 protein expression and suppressed the NF­κB/MMP9 signaling pathway in U87 cells. Furthermore, downregulation of miR­16 using the anti­miR­16 plasmid reversed the effect of apigenin on cell viability, BCL2 protein expression and the NF­κB/MMP­9 pathway in U87 cells. The results of the present study suggested that apigenin inhibits glioma cell growth through promoting miR­16 and suppression of BCL2 and NF-κB/MMP-9. In conclusion, the present study demonstrated the potential anticancer effects of apigenin on glioma cells.

[Comparison of different modes of using tranexamic acid administration on reducing hidden blood loss in total hip arthroplasty].

OBJECTIVE: To compare the clinical efficacy of using tranexamic acid in different ways to reduce the hidden blood loss in patients who receiving total hip arthroplasty (THA). METHODS: Totally 68 patients with osteonecrosis of the femeral head treated by total hip arthroplasty in our hospital from February 2010 to July 2015 were randomly divided into the intravenous drip group (group A) and the topical application group (group B). In group A, there were 19 males and 15 females, with an average age of (62.0±6.4) years old, preoperative average hemoglobin was (121.30±8.15) g/L, average Hematocrit was (0.470±0.039) L/L. In group B, there were 18 males and 16 females, with an average age of (64.0±7.5) years old, preoperative average hemoglobin was (125.28±9.37) g/L, average Hematocrit was (0.490±0.041) L/L. The operation incision were performed through the posterolateral approach and the normal operation mode, biological prosthesis was selected. Through different ways the tranexamic acid was used to control of intraoperative and postoperative bleeding. Tranexamic acid was intra articular injection as a dose of 10 mg/kg 10 min to patient before anesthesia in intravenous drip group. In topic group, 3 g of tranexamic acid was dissolved in 120 ml saline and divided into three equal parts, then two pieces of gauze were immersed in 40 ml tranexamic acid solution. One gauze with 40 ml tranexamic acid was used to soak the acetabulum for 5 minutes after the acetabular preparation, another gauze was inserted in the femoral canal for 5 minutes after femoral canal broach preparation. The remaining 40 ml tranexamic acid fluid was injected into the hip joint after fascia closure. Place the drainage tube and clip it for 3 hours. Hemoglobin (Hb) and Hematocrit (Hct) were recorded at 72 hours after operation. The total blood loss, dominant blood loss, and hidden blood loss were calculated. RESULTS: In group A, postoperative hemoglobin difference before and after operation was (32.34±7.42) g/L, total blood loss was (833.6±81.4) ml, the hidden blood loss was (276.3±57.9) ml, red blood cell volume was (10.1±1.4) L/L;In group B, hemoglobin difference before and after operation was (28.2±6.1) g/L, total blood loss was (792.5±61.8) ml, the hidden blood loss was (297.5±50.3) ml, red blood cell volume was (9.2±1.2) L/L. There was no statistical significance about those aspect (P>0.05). Compared of blood coagulation function between two groups, in group A: PT (12.78±2.03) s, APTT (34.27±3.91) s, INR (32.34±7.42); and in group B: PT (13.17±2.19) s, APTT (32.36±3.18) s, INR (28.24±6.14). There was no significant differences also (P>0.05). CONCLUSIONS: Compared with intravenous application, topical application of tranexamic acid could also effectively reduce total blood loss and hidden blood loss, postoperative blood transfusion rate in primary total hip arthroplasty, while does not increase the risk of DVT.

Anti-carcinogenic activity of anandamide on human glioma in vitro and in vivo.

The poor prognosis of gliomas is to a large extent attributed to the markedly proliferative and invasive nature of the disease. Endocannabinoids have emerged as novel potential anti-tumor agents. The present study aimed to investigate the anti-carcinogenic activity of anandamide (AEA), an endocannabinoid, on glioma cells. To assess the functional role of AEA in glioma, the effects of AEA on cell proliferation, migration, invasion, apoptosis and the cell cycle in vitro, and tumor growth in vivo, were investigated. AEA markedly inhibited the proliferation of U251 cells in a dose- and time-dependent manner. Flow cytometric assays revealed that the apoptosis rate of U251 cells upon treatment with AEA was increased. AEA also suppressed the adhesion, migration and invasion capabilities of the U251 cells. Furthermore, AEA inhibited tumor growth in vivo. These results highlighted the potential role of AEA in the tumorigenesis and progression of glioma, and suggested that AEA exhibits therapeutic potential in the management of human glioma.

[A study on feeding ecology and migration patterns of Dosidicus gigas off Peru using stable isotope analysis].

As a pelagic cephalopod and one of the main target species of Chinese distant water fishery, jumbo squids (Dosidicus gigas) play a major role in the marine ecosystems of the eastern Pacific. Understanding the feeding ecology and migration patterns of jumbo squids is of importance for better utilizing the resources. The isotopic signatures of gladius, have been proved to be a powerful tool to reveal high resolution and ontogenic variations in individual foraging strategies of squids; which is an archival tissue with no elemental turnover after formation. In this study, the growth equation of gladius proostracum was established based on the age information determined by statolith. Gladius was cut successionally by the growth curve of gladius proostracum, the stable isotopic values of the gladius profiles were determined, and the feeding ecology and migration patterns of jumbo squids during its growth process were investigated. Results showed that the jumbo squids began to migrate after 180 days of postnatal, and their trophic levels tended to decrease throughout the life span. These results demonstrated the feasibility of using continuous sampling hard tissue to study the feeding ecology and habitat transfer of jumbo squids.

[Trace elements in the statoliths of neon flying squid, Ommastrephes bartramii in the Northwest Pacific Ocean].

Statolith is one of the most important hard tissues of cephalopods which is widely used in the research of fisheries ecology including population structure, life history reconstruction and so on. Trace elements of 18 statoliths of neon flying squid Ommastrephes bartramii collected in the Northwest Pacific Ocean in 2007 by Chinese jigging fishing fleets were analyzed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The results indicated that the statoliths of O. bartramii mainly contained 55 elements, and calcium (Ca), strontium (Sr), sodium (Na), phosphorus (P), potassium (K), silicon (Si), magnesium (Mg), boron (B), iron (Fe), barium (Ba) were the 10 most abundant elements. The analysis of variance showed that there was no significant difference in each element distribution between different sexual squid except for P, Si and B. Significant differences existed in the contents of Sr and Na but no significant difference was found in the contents of Ca, P, K, Si, Mg, B, Fe and Ba between different hatching populations. There were significant differences in the contents of Ca, Sr, Na, P, Mg and Ba, but no significant difference was found in the contents of K, Fe, B and Si in the statoliths among different growth zones. This study presented Sr and Na could be the best two trace elements used in the research on the population structure and life history reconstruction for O. bartramii.

Oncolytic adenovirus-expressed RNA interference of O6-methylguanine DNA methyltransferase activity may enhance the antitumor effects of temozolomide.

Temozolomide (TMZ) is an example of an alkylating agent, which are known to be effective anticancer drugs for the treatment of various solid tumors, including glioma and melanoma. TMZ acts predominantly through the mutagenic product O6-methylguanine, a cytotoxic DNA lesion. The DNA repair enzyme, O6-methylguanine DNA methyltransferase (MGMT), which functions in the resistance of cancers to TMZ, can repair this damage. RNA interference (RNAi) has been previously shown to be a potent tool for the knockdown of genes, and has potential for use in cancer treatment. Oncolytic adenoviruses not only have the ability to destroy cancer cells, but may also be possible vectors for the expression of therapeutic genes. We therefore hypothesized that the oncolytic virus-mediated RNAi of MGMT activity may enhance the antitumor effect of TMZ and provide a promising method for cancer therapy.

[Applications of stable isotope analysis in the trophic ecology studies of cephalopods].

Cephalopods play an important role in marine food webs, however, knowledge about their complex life history, especially their feeding ecology, remains limited. With the rapidly increasing use of stable isotope analysis (SIA) in ecology, it becomes a powerful tool and complement of traditional methods for investigating the trophic ecology and migration patterns of invertebrates. Here, after summarizing the current methods for trophic ecology investigation of cephalopods, applications of SIA in studying the trophic ecology of cephalopods were reviewed, including the key issues such as standardization of available tissues for SIA analyzing, diet shift and migration patterns of cephalopods, with the aim of advancing its application in the biology of cephalopods in the future.

[Effects of lipid extraction on stable carbon and nitrogen isotope analyses of Ommastrephes bartramii muscle].

Stable isotope analysis (SIA) has become an important tool to investigate diet shift, habitat use and trophic structure of animal population. Muscle is considered to be the most common tissue for SIA, however, lipid content in muscle causes a considerable bias to the interpretation of isotopic ratios of animals. Neon flying squid (Ommastrephes bartramii) is an important economic cephalopod of Chinese distant water fishery, and plays a major role in marine ecosystems. In this study, the effects of lipid extraction on stable isotope ratios of the muscles of 53 neon flying squids were investigated and the interference mechanism of lipid in SIA was clarified with the aim of contrasting the suitability of different lipid correction models of stable carbon isotope. Results showed that the stable carbon and nitrogen isotopic values of non-lipid extracted samples significantly increased after lipid extractions by 0.71 per thousand and 0.47 per thousand, respectively, which suggested that lipid extraction in cephalopod isotope study is needed prior to stable carbon isotope analysis but not recommended for stable nitrogen isotope analysis. The results could help remove the effects of lipid contents and standardize SIA muscle samples, thereby getting better understanding of the isotopic change of neon flying squids in the future.