Effect of Long-Term Low-Salinity Culture on the Survival,Growth, and Nutrient Composition of Mud Crab Scylla paramamosain     

JI Zilu  LI Ronghua  WANG Chunlin  ZHANG Zhouyi  ZHANG Weijia  MU Changkao  SONG Weiwei 《中国海洋大学学报(英文版)》2022,21(1):179-185

This study investigated the effects of long-term low-salinity on the growth performance,proximate composition,amino acid and fatty acid profiles of Scylla paramamosain.The salinity of the low-salinity-culture group(LC)and maintained-salinity-cul-ture group(MC)were set at 5 and 25 respectively.After rearing for 30 d,the survival rate(SR)of the LC group was significantly lower,whereas the average daily molting frequency(ADMF)was significantly higher than those in MC group(P<0.05).There were no significant difference for weight gain rate(WGR)and specific growth rate(SGR)between the two groups.The moisture content of the LC group was slightly higher than the MC group without significant difference.The contents of ash,crude lipid and crude pro-tein in the LC group were lower than those in the MC group,but no significant differences were found except for ash content.A total of 17 free amino acids and 23 fatty acids were identified from the muscle of S.paramamosain.The total amino acids(TAA),essen-tial amino acids(EAA)and essential amino acid index(EAAI)had no significant difference between the two groups.The crabs from LC group had a significantly higher HUFA,including EPA,DHA,ARA.The percentage of n-3 PUFA and the ratio of n-3/n-6 PUFA were significantly higher in the LC group.These results indicated that S.paramamosain rearing at low salinity had significantly de-creased SR;however,the low-salinity environment significantly promoted the accumulation of unsaturated fatty acids(UFAs),espe-cially the n-3 PUFA,which might be related to the osmoregulation mechanism.  相似文献   

Characteristics Analysis and Risk Assessment of Extreme Water Levels Based on 60-Year Observation Data in Xiamen,China     

MIAO Qingsheng  YUE Xinyang  YANG Jinkun  WANG Zhifeng  XU Shanshan  YANG Yang  CHU Siqi 《中国海洋大学学报(英文版)》2022,21(2):315-322

Extreme water levels are related to astronomical tides and storm surges.Eleven typhoon systems,which have caused extreme water level rises,were selected based on 60-yr water level data from the Xiamen tide gauge station.In these 11 typhoon systems,the astronomical tide component accounts for 71%-95%of the total water level.The Gumbel distribution of extreme water level rise was estimated,and the impact of typhoon surges on water levels during the return period was analyzed.The ex-treme tide levels caused by typhoons Herb(1996)and Dujuan(2015)are much higher than those of other typhoons and correspond to the return period of 76 yr and 71 yr,respectively.The differences of sea levels in the presence and absence of these two typhoons in the 10-100 yr return period are 5.8-11.1 cm.For the 100-yr return period,the total risks within 10,25,50,and 100 yr increase by 94.3%,85.4%,72.9%,and 54.4%,respectively,if the Herb and Dujuan are not considered.Assuming that typhoon Herb(1996)occurred during the highest astronomical tide,it will produce a water level higher than that of the 1000-yr return period.Sea level rise has an important influence on the water level return period,and the contribution of nonlinear sea level rise in the next 100 yr is estimated to be 10.34%.  相似文献   

Evaluation of the Bioavailability of Metals in Sediment from the Southern Coastal Wetland of the Qiantang Estuary by Using Diffusive Gradients in Thin Films Technique     

FENG Weihua  WANG Zhifu  ZHU Wenzhuo  ZHENG Fangqin  ZHANG Dongrong  XU Hengtao 《中国海洋大学学报(英文版)》2022,21(2):375-387

Metal pollution has become an major issue governing the wetland ecosystem health.The southern coastal wetland of the Qiangtang Estuary are facing unusual perturbation due to rapid development along the embayment in recent decades.This study evaluated the bioavailability of metals(Cu,Pb,Cd,Cr and Zn)in the sediment of the southern coastal wetland of the Qiangtang Es-tuary using diffusive gradients in thin films(DGT)techniques and compared with several methods based on total metal content.The results showed that the contents of Cr,Pb,Cd and Cu in sediment,as detected using DGT,were considerably correlated with the exchangeable fraction and the content in Phragmites australis roots,while a weak correlation was observed for Zn.Therefore,DGT analysis could be used to evaluate the bioavailability and potential risk of Cr,Cd,Pb and Cu for P.australis.Quantitative indices,such as DGT concentration,bioaccumulation in P.australis,geoaccumulation index(Igeo)and potential ecological risk index(RI),revealed that Cd was a major potential ecological risk factor along the southern coast wetland of the Qiantang Estuary,especially in the upstream region,which is potentially more vulnerable to the anthropogenic pollution.  相似文献   

Otolith Microstructure Analysis Reveals Different Growth Histories of Japanese Sardine (Sardinops melanostictus) in the Oyashio Waters     

LIU Chunlin  ZHANG Chi  TIAN Yongjun  WANG Liangming  LIN Longshan  LI Yuan  WATANABE Yoshiro 《中国海洋大学学报(英文版)》2022,21(1):236-242

After decades of low year classes,the stock of Japanese sardine(Sardinops melanostictus)has begun to recover since the mid-2000s.The hatch dates and otolith growth rates of age-0 juvenile sardine,which were collected in the subarctic Oyashio waters in autumn 2018,were determined from an otolith microstructure analysis.The sardines were hatched from late January to late April,while mostly in February and March.The otolith growth rate increased continuously up to 60 d after hatching and thereafter de-creased.The revealed growth rate in a crucial growth period is faster than that reported for juvenile sardines collected in the 1990s,which is coincided with the recent recovery trend of the sardine stock.Two groups with different hatch dates,growth histories,and migration routes were identified using unsupervised random forest clustering analysis.They were considered inshore and offshore migration individuals in accordance with recent researches.In the offshore group,a high proportion of sardine juveniles hatched late and grew faster in the Kuroshio-Oyashio transitional waters,a finding consistent with the hypothesis of growth-rate-dependent re-cruitment.This finding on the population composition and growth rate of juvenile sardine in the Oyashio waters can be a basis for an improved prediction of their survival and provides us with valuable information on the recruitment processes of this stock during the period of stock recovery.  相似文献   

Effects of Environmental Cadmium on Cadmium Accumulation,Oxidative Response,and Microelements Regulation in the Liver and Kidney of Hexagrammos otakii     

HU Fawen  SUN Ming  LI Li  GAO Fengxiang  JIAN Yuxia  WANG Xue  WANG Xiaolong  GUO Wen 《中国海洋大学学报(英文版)》2022,21(2):479-485

The effects of cadmium(Cd)on metal accumulation,microelements contents,and antioxidant responses in Hexagram-mos otakii were studied.The fish were exposed to 0.2,2.5,or 10μg L?1 Cd for 12 or 24 days.Then,the concentration of Cd and mi-croelements(Ca,Fe,Zn,and Se)were determined in the liver and kidney.Moreover,the activities of antioxidant enzymes including superoxide dismutase(SOD),catalase(CAT),and glutathione-S-transferase(GST),and the content of malondialdehyde(MDA)in the liver and kidney were also measured.A continuous accumulation of Cd was observed throughout the experimental period.Cd accumulation was higher in liver than that in the kidney,while Ca and Fe contents were lower in liver than those in the kidney.Cd exposure resulted in a decrease of Ca and Fe concentrations in the kidney,while there was no effect on the liver.Zn and Se remained unaffected with exposure to Cd.Cd exposure induced severe oxidative stress in H.otakii,as indicated by significant induction of the activities of SOD,CAT,and GST,and a simultaneous increase of MDA content.These data show that antioxidant enzymes and mi-croelements contents can be used as potential biomarkers to monitor environmental health in fish.  相似文献   

不同方法提取马氏珠母贝外套膜胶原蛋白理化性质比较     

林海生  王雯  秦小明  曹文红  章超桦  高加龙  郑惠娜  陈忆宾  伍彬 《广东海洋大学学报》2022,(1)

【目的】系统分析不同方法提取的马氏珠母贝(Pinctada martensii)外套膜胶原蛋白的理化性质及生物学功能。【方法】分别采用酸-酶法和热水法从外套膜中提取得到两种胶原蛋白(A-PSC(Pm)和HSC(Pm)),对其氨基酸组成、微观结构及热变性温度等理化特性进行比较分析。【结果】HSC(Pm)提取率高于A-PSC(Pm);HSC(Pm)中,Gly、Glu与Arg相对含量较高,分别为20.16%、17.57%和10.07%;而A-PSC(Pm)中,Glu、Asp与Arg相对含量为19.67%、11.63%和10.07%;紫外光谱和红外光谱分别显示,两种胶原蛋白均在220 nm左右有强吸收峰,且具有典型的胶原蛋白特征带(酰胺A、B、Ⅰ、Ⅱ和Ⅲ带);扫描电镜结果显示,A-PSC(Pm)呈致密多孔网状结构,HSC(Pm)则基本为薄片状;DSC分析结果表明,HSC(Pm)具有更好的热稳定性。【结论】酸-酶法及热水法提取的胶原蛋白均具有类V型胶原蛋白特性,其结构特征及其理化性质均存在差异,可根据需求选择特定的胶原蛋白提取方法用以开发不同类型的产品。  相似文献   

Literature analysis of Dendrolimus disasters based on remote sensing monitoring     

WANG Mingchang  ZHOU Yuyang  LI Mingjie  JI Xue  LIU Ziwei 《世界地质(英文版)》2022,25(1):49-59

Due to global climate change,Dendrolimus pests and diseases seriously threaten the protec-tion of forestry plants and the safety of crops all over the world.This paper aims to discuss the research results and frontier progress of Dendrolimus disasters based on remote sensing monitoring,trying to find the occurrence characteristics of pests.In this paper,bibliometric methods and CiteSpace knowledge graphs were used to analyze the publication trend,highly cited documents,key research institutions,and high-frequency keywords of the extracted documents in the Web of Science(WOS)database.The following conclusions are drawn:(1)The amount of research in WOS is on the rise,but it has declined in recent years.The countries with strong influence in national cooperation are mainly the United States and China.(2)The United States Department of Agriculture-Agricultural Research Service(USDA ARS)and the Chinese Academy of Sciences have published a lot.This paper reviewed the research progress of high-frequency institutions.(3)The key research topics focus on remote sensing,agriculture,and environmental sciences.Besides,the research hotspots include remote sensing monitoring,climate change,spectral reflectance,vegetation index,and precision agriculture.Finally,we put forward the current challenges and development trends of remote sensing pest monitoring.This paper can provide a reference for the research on remote sensing monitoring of Dendrolimus disasters in the future.  相似文献   

关于提高安徽地质找矿效果的几点思考     

王朝义 《安徽地质》2005,15(1):74-76,80

提高安徽地质找矿效果是一项十分紧迫而艰巨的工作．意义重大。文章分析了我省目前地勘工作的现状和存在的不足,对下步如何切实提高我省的地质找矿效果提出了一些建议和思考。指出按客观规律办事、强化科学管理是提高找矿效果的前提;建立专家系统,选准、选好项目是提高找矿效果的基础;集中找矿力量、建立省直属综合找矿队伍是提高找矿效果的关键。  相似文献   

地面地下空间信息采集车及试验结果     

王新洲  花向红  龚俊  向东 《测绘工程》2006,15(6):34-38

介绍地面地下空间信息采集车的原理和结构,给出了利用GPS-RTK辅以全站仪和地下管线探测仪实现地下管线勘、测、管一体化的原理,以及获取管线三维坐标的数学模型。通过试验验证了地面地下空间信息采集车的可行性,其精度满足《城市地下管线探测技术规程》的要求。  相似文献   

MATLAB环境下遥感影像配准与融合技术研究   总被引：1，自引：0，他引：1  

朱朝杰  王仁礼  董广军 《测绘工程》2006,15(6):57-59

对基于高通滤波的加权融合法和HIS融合变换法在MATLAB环境下进行了算法研究与实现,结果表明在较好地保留原图像光谱信息的同时大大提高了图像空间分辨率,且提高了工作进程和效率。  相似文献