The carotenoid characteristics of the important wild shrimp Trachysalambria curvirostris(Stimpson,1860) in China

Trachysalambria curvirostris is an economically important shrimp in the coastal waters of the Western Indo-Pacific. However, there is no information about its carotenoid composition and distribution. The carotenoid profiles including concentration, composition, molecular forms (free or esterified) and configuration (geometrical and optical isomers) of raw and dried T. curvirostris (Stimpson, 1860) were qualitatively and quantitatively assessed. In the raw shrimp, astaxanthin and β-carotene were the two dominant carotenoids, which contributed 75.18%–88.86% and 2.86%–16.83% of the total carotenoid content. Traces of echinenone, canthaxanthin and astacene were also detected. The carotenoid content in the waste (80.28 mg/kg dry weight) was nearly two-fold higher than that in the meat (49.69 mg/kg dry weight). Of the total astaxanthin in these shrimp, 85.18%–90.59% was esterified. All- trans astaxanthin was the predominant geometrical isomer followed by 13- cis , 9- cis , di- cis and 15- cis isomers. A mix of three stereoisomers was found in all parts and the percentages of meso (3 S , 3’ R ) and (3 S , 3’ S ) forms were significantly higher than the (3 R , 3’ R ) isomer. Compared to the carotenoid content of the raw shrimp, only 26.17 mg/kg remained in the dried shrimp. Nearly half of the carotenoids were lost during the drying process. Substantial hydrolysis and isomerization also occurred.     

浙江沿岸海域虾类优势种空间生态位分析

生态位与种间竞争、资源利用密切联系,体现了物种在群落中利用资源的能力。为探明浙江沿岸海域虾类分布格局的形成和影响因素,通过相对重要性指数确定了虾类群落优势种,分别采用Levins公式和Pianka指数计测了虾类优势种生态位宽度和生态位重叠,并通过典范对应分析（CCA）研究生态位分化情况。结果表明:研究海域共出现13种虾类优势种,根据生态位宽度大小将研究海域内的虾类优势种分为3类,细巧仿对虾、细螯虾、鲜明鼓虾和中华管鞭虾属于第一类群,以上4种虾类的空间生态位宽度较宽;日本鼓虾、哈氏仿对虾、鹰爪虾、中国毛虾和葛氏长臂虾属于第二类群,这5种虾类空间生态位略低于第一类群,但其生态位仍相对较宽;戴氏赤虾、脊腹褐虾、东海红虾和大管鞭虾这4种虾类的空间生态位较窄,属第三类群;生态位重叠指数变化范围在0.00~0.78,将重叠指数按照大于0.6、0.3~0.6和小于0.3划分为重叠度较高、重叠度较低和重叠度低3个重叠度等级,结果表明,虾类优势种生态位重叠以较低和低2个等级为主;虾类分布受水深、底层溶解氧和底层盐度的影响较大,受水温影响较小。虾类群落优势种空间生态位与生活习性、种间竞争、摄食以及海洋环境因子等多种因素有关。     

海州湾及邻近海域口虾蛄栖息地适宜性建模的环境变量优化

Habitat suitability index(HSI) models have been widely used to analyze the relationship between species abundance and environmental factors, and ultimately inform management of marine species. The response of species abundance to each environmental variable is different and habitat requirements may change over life history stages and seasons. Therefore, it is necessary to determine the optimal combination of environmental variables in HSI modelling. In this study, generalized additive models(GAMs) were used to determine which environmental variables to be included in the HSI models. Significant variables were retained and weighted in the HSI model according to their relative contribution(%) to the total deviation explained by the boosted regression tree(BRT). The HSI models were applied to evaluate the habitat suitability of mantis shrimp Oratosquilla oratoria in the Haizhou Bay and adjacent areas in 2011 and 2013–2017. Ontogenetic and seasonal variations in HSI models of mantis shrimp were also examined. Among the four models(non-optimized model, BRT informed HSI model,GAM informed HSI model, and both BRT and GAM informed HSI model), both BRT and GAM informed HSI model showed the best performance. Four environmental variables(bottom temperature, depth, distance offshore and sediment type) were selected in the HSI models for four groups(spring-juvenile, spring-adult, falljuvenile and fall-adult) of mantis shrimp. The distribution of habitat suitability showed similar patterns between juveniles and adults, but obvious seasonal variations were observed. This study suggests that the process of optimizing environmental variables in HSI models improves the performance of HSI models, and this optimization strategy could be extended to other marine organisms to enhance the understanding of the habitat suitability of target species.     

海洋微藻的体外抗肿瘤活性初筛

采用小鼠乳腺癌细胞株tsFT210的细胞周期抑制、细胞凋亡诱导、细胞坏死以及对卤虫的毒性为活性指标,对48种海洋微藻的甲醇提取物的抗肿瘤活性进行了筛选。结果表明,以卤虫毒性为活性指标时,9种海洋微藻显示了不同程度的抗肿瘤活性,以tsFT210为筛选模型时,也有9种具有抗肿瘤活性,其中3种为明显的细胞凋亡诱导活性、2种为细胞坏死性活性、1种为G2/M期抑制活性,因此有必要进行开拓海洋微藻药用新资源的研究。     

日本对虾亲虾性腺多次成熟利用的研究

日本对虾(Penaeus japonicus)是我国海水养殖的主要经济种类之一.近年来,对虾养殖业经受严重滑坡,人们对原来北方地区主养中国对虾(P.chinesis),南方主养斑节对虾(P.monodon)的格局在养殖品种选择上也作了相应的调整,日本对虾倍受青睐,其养殖面积及区域不断扩大,目前,我国南起海南北至辽宁均已形成大规模生产,并日益扩大[1].     

对虾与鱼、贝类封闭式综合养殖的实验研究

于1995－1999年采用陆基实验围隔法系统地研究了对虾与鱼、贝类封闭式综合养殖的基础问题，所选取的材料为中国对虾、台湾红罗非鱼、缢蛏与海湾扇贝，研究出了4种优化结构养殖模式。结果表明，4种模式的组成及各成分间生物量（收获前）的比值分别为：对虾的养殖效果都比同样条件下的对虾单养模式显著优越；其中最好的虾、鱼、贝三元综合养殖模式将产量提高了28％，投入氮的利用率提高了85％。同时采取封闭式的养殖方法，向浅海输出的氮只占养殖输入氮的6％－8％，从而显著降低了对浅海的污染。     

不同养殖模式虾池弧菌对抗菌药物的耐药性与虾池水质评价

研究了湛江东海岛3种不同养殖模式虾池弧菌对抗菌药物的耐药性,并对虾池水域环境的水温、盐度、DO、pH、叶绿素a、DOC、无机氮、无机磷、硅酸盐、细菌总数和弧菌数量变化进行了监测和评价。结果表明,调查的三个虾池的弧菌对万古霉素产生耐药性,高位新池和传统精养池的弧菌对利福平产生耐药性,对其他抗菌药尚未形成耐性,3个虾池的弧菌对恩诺沙星和氯霉素高度敏感,传统精养池和天然虾池的弧菌对复方新诺明、庆大霉素、TMP和环丙沙星高度敏感;在水平差异上,高位新池的弧菌比传统精养池和天然虾池对12种抗菌药更具耐药性,同时多重耐药菌株在高位新池中出现,可能与虾苗来源和配合饲料中添加了抗菌药物有关。水质监测结果表明,养殖过程中,虾池水域环境逐渐富营养化,无机氮和Chla超过富营养化阈值,细菌总数增加;两个精养池的水体富营养化程度高于天然虾池;调查期间的弧菌数量在对虾发病的感染剂量阈值范围之内,尚无弧菌病害发生的潜在危险。     

Contrasting on Hydrocarbon Generation Model and Characteristics of Pyrolysis of Modern Aquatic Plant (Gloeocapsa) vs Marine Animal (Mantis Shrimp)

INTRODUCTIONGeochemical models of hydrocarbon generation fromorganic matter have become increasingly important inhydrocarbon exploration. They elucidate the relationshipbetween precursor organic materials and the properties ofhydrocarbon products under certain geologic conditions.Previous thermal experiments were successful to a certaindegree in sim ulating the geologic process of hydrocarbonevolution. Khorasani and Michelson (1991) reported thegeneration of liquid hydrocarbon from the co…     

Comparative study on the allergenicity of different Litopenaeus vannamei extract solutions

Allergen extracts are widely used for allergy diagnosis and treatment. The application of shrimp extract is hampered due to the low protein concentration and the inconsistent allergenicity. Extracting solutions are considered to be the primary limiting factor of protein extraction from crustaceans. This study aimed to select an optimal solution for shrimp protein extraction by comparing the allergenicity of different shrimp extracts. The effect of 7 existing or modified extracting solutions were evaluated, including the glycerol-NaCl solution, the glycerol Cocaine's solution, the buffered saline solution, the Cocaine's solution, the Glucose leaching solution, 1 mol L-1 KCl solution, and 0.01 mol L-1 phosphate buffered saline solution with and without dithiothreitolor(DTT). The quantitative(protein concentration) and qualitative parameters(SDS-PAGE protein patterns and immuno-reactivity) were determined using the sodium dodecyl sulfate polyacrylamide gel electrophoresis, enzyme linked immunosorbent assay and immunoblotting assay. Results showed that the 1 mol L-1 KCl solution with DTT was optimal for shrimp protein extraction, which yielded high concentration and allergenicity in the protein extract, including major and minor allergens. The 1 mol L-1 KCl solution with DDT is proposed for preparation of shrimp extract and associated allergy diagnosis, as well as potential applications for other crustaceans.     

Isolation and identification of a bacterium from marine shrimp digestive tract: A new degrader of starch and protein

It is a practical approach to select candidate probiotic bacterial stains on the basis of their special traits. Production of digestive enzyme was used as a trait to select a candidate probiotic bacterial strain in this study. In order to select a bacterium with the ability to degrade both starch and protein, an ideal bacterial strain STE was isolated from marine shrimp (Litopenaeus vannamei) intestines by using multiple selective media.The selected isolate STE was identified on the basis of its morphological, physiological,and biochemical characteristics as well as molecular analyses. Results of degradation experiments confirmed the ability of the selected isolate to degrade both starch and casein. The isolate STE was aerobic, Gram-negative, rod-shaped, motile and non-spore-forming, and had catalase and oxidase activities but no glucose fermentation activity. Among the tested carbon/nitrogen sources, only Tween40, alanyl-glycine, aspartyl-glycine, and glycyl-l-glutamic acid were utilized by the isolate STE. Results of homology comparison analyses of the 16S rDNA sequences showed that the isolate STE had a high similarity to several Pseudoalteromonas species and, in the phylogenetic tree, grouped with P. ruthenica with maximum bootstrap support (100%). In conclusion, the isolate STE was characterized as a novel strain belonging to the genus Pseudoalteromonas.This study provides a further example of a probiotic bacterial strain with specific characteristics isolated from the host gastrointestinal tract.