三种海水蟹类血淋巴细胞的比较

采用Wright’s-Geimsa混合染料对三疣梭子蟹、锈斑蜉和锯缘青蟹的血淋巴细胞进行染色，光镜下对这三种海水蟹的血淋巴细胞进行了观察和比较。根据血淋巴细胞的核质比、细胞整体着色特点、细胞质中颗粒的存在与否、颗粒的数量和分布等，三种海水蟹的血淋巴细胞均可分为颗粒细胞、半颗粒细胞和透明细胞三种主要类型，三种蟹的同类血淋巴细胞在染色形态上稍有差别。三种蟹的颗粒细胞大小差异较大，而半颗粒细胞和透明细胞大小相近。三种蟹的血淋巴细胞均以半颗粒细胞为主，透明细胞在血淋巴细胞中所占比例最小。三种蟹的血淋巴细胞密度均存在明显的雌雄差异，锈斑蜉和锯缘青蟹血淋巴细胞分类计数也存在明显的雌雄差异。     

文蛤Meretrix meretrix血细胞形态与分类

光镜观察湛江南三地区文蛤血细胞的形态与结构特征,并进行分类。按细胞大小、形态和结构特征可将文蛤血细胞分为4类:透明细胞、小颗粒细胞、大颗粒细胞和淋巴细胞。细胞直径有统计学上显著性差异(P<0.05),分别为10.11±0.44μm、10.99±0.32μm、9.63±0.41μm和9.22±0.25μm。透明细胞是血细胞中的主要成分,细胞质中无颗粒;小颗粒细胞的细胞质中存在大量细小颗粒;大颗粒细胞细胞质中的颗粒直径有1.0～2.5μm;淋巴细胞是血细胞中含量最少的,有很高的核质比,大约为0.5。     

锯缘青蟹繁殖生物学的研究

为解决锯缘青蟹的种苗生产问题，较系统地研究了其繁殖生物学的有关问题。结果表明，锯缘青蟹的繁殖季节是3－10月，体重130g以上的青蟹均有交配、生殖能力，雌雄比例近1∶1，采用促熟措施可达到雌蟹早产卵的目的；适宜胚胎发育水温是20－30℃，当水温25－30℃时，幼体发育随水温增高而加快。并描述了幼体各期的主要特征。     

锯缘青蟹繁殖生物学的研究

为解决锯缘青蟹的种苗生产问题 ,较系统地研究了其繁殖生物学的有关问题。结果表明 ,锯缘青蟹的繁殖季节是 3～ 1 0月 ,体重 1 3 0g以上的青蟹均有交配、生殖能力 ,雌雄比例近 1∶1 ,采用促熟措施可达到雌蟹早产卵的目的 ;适宜胚胎发育水温是 2 0～ 3 0℃ ,当水温 2 5～ 3 0℃时 ,幼体发育随水温增高而加快。并描述了幼体各期的主要特征     

东海中南部海域锈斑蟳渔业生物学和数量分布

研究了1998—1999年东海区虾蟹类调查所获的部分锈斑蟳样品与1998~2004年在东海拖虾作业与蟹笼作业等周年逐月渔获物中采集的锈斑蟳样品的生物学特性,结果表明:东海锈斑蟳渔获群体的甲长范围为26~105mm,甲宽范围为36~165 mm,体重范围为5~610 g,雄性个体平均要略大于雌性个体;周年雌蟹略多于雄蟹,性比为1∶0.94,繁殖期为7~12月,繁殖高峰期为8~10月,不同个体怀卵量在113 867~1 594 167粒之间;调查海区10月开始出现幼蟹,5月生长加速,最小抱卵个体的甲长为60 mm,甲宽为85 mm,体重为110 g。另根据1998~1999年调查资料分析得知:锈斑蟳主要分布在长江口渔场以南水深60 m以内海域,中心区分布在闽东渔场,渔期为11月~翌年2月,是舟山、长江口渔场三疣梭子蟹汛期结束后,蟹笼、流刺网作业的又一主捕对象。     

东海中南部海域锈斑蟳渔业生物学和数量分布

研究了1998-1999年东海区虾蟹类调查所获的部分锈斑蟪样品与1998—2004年在东海拖虾作业与蟹笼作业等周年逐月渔获物中采集的锈斑蟳样品的生物学特性，结果表明：东海锈斑蟳渔获群体的甲长范围为26—105mm，甲宽范围为36—165mm，体重范围为5—610g，雄性个体平均要略大于雌性个体；周年雌蟹略多于雄蟹，性比为1：0．94，繁殖期为7-12月，繁殖高峰期为8—10月．不同个体怀卵量在113867—1594167粒之间：调查海区10月开始出现幼蟹，5月生长加速，最小抱卵个体的甲长为60mm，甲宽为85mm，体重为110g。另根据1998—1999年调查资料分析得知：锈斑蟳主要分布在长江口渔场以南水深60m以内海域，中心区分布在闽东渔场，渔期为11月-翌年2月，是舟山、长江口渔场三疣梭子蟹汛期结束后，蟹笼、流刺网作业的又一主捕对象。     

锯缘青蟹人工育苗研究初报

锯缘青蟹(Scylla serrata)俗称为青蟹。肉质肥满的雄蟹或雌蟹俗称为肥蟹。卵巢成熟的雌蟹俗称为膏蟹。其肉味特别鲜美,是人民群众喜食的海味,也是传统出口的水产品之一。并有药用价值,有滋补、消肿的功能,可治水肿等疾病。蟹壳可制成甲壳素,在工业上有重要的用途。还可从蟹壳中提取味精,或将蟹壳磨成粉,做禽畜的饲料,能使禽畜多长膘、多下蛋。     

锯缘青蟹围塘养殖试验

1998～ 1999年间在阳东县采用改造蟹池、水质调控、合理投饵、轮捕轮放等技术进行锯缘青蟹围塘养殖试验。结果表明 ,锯缘青蟹成活率为 70 .9% ,比 1998年提高 4 0 % ;平均产量 32 6 7kg hm2 ,比 1998年提高 12 2 .3%。 1999年与 2 0 0 0年推广养殖面积各为 10 3hm2 与 137.3hm2 ,平均产量分别为 30 5 9kg hm2 与 3132kg hm2 ,与 1998年相比分别提高 10 8.3%与 113.3%。     

对虾与锯缘青蟹混养的可行性及其增产措施

对虾与锯缘青蟹 Scylla serrata(Forskal)混养(下称虾蟹混养)国内、外尚未见有系统的理论研究资料。作者经过几年研究,证实虾蟹混养非但可行,而且可以提高海水池塘综合经济效益。本文从理论与实践的结合上论述虾蟹混养的可行性及其增产措施。     

勒氏笛鲷外周血细胞显微结构的观察

报道了勒氏笛鲷外周血细胞的显微结构,血涂片经过Wright染色液染色,可区分出红血细胞、血栓细胞、嗜中性粒细胞、单核细胞、淋巴细胞等五种血细胞,没有发现嗜碱性粒细胞、嗜酸性粒细胞.白血细胞中,血栓细胞体积最小,单核细胞体积最大;血栓细胞数目最多,淋巴细胞和单核细胞数目最少;淋巴细胞有大小两种类型大淋巴细胞和小淋巴细胞.此外,在外周血液中还观察到少量未成熟的红细胞和嗜中性粒细胞,偶而可见正在分裂的红细胞,提示红细胞也可在外周血直接分裂.     

EVALUATION ON NUTRITIVE VALUE OF PORTUNUS TRITUBERCULATUS

MODUon0NP.trituberculatushasanupswellingshuttiedsecephalothoraxcrust0nWhosescheearemanydiversefinegranuleswhichbererneroughandconcentIatalinthegillaas.IthasthIeewartybulgesandtwosharpodhonitSforeheadPaiAiy-U,l986).Thechelipedisdeveloped,itSmerusisshuuleshaped,thefotirthpairofpereiopodsareuseoars,itScarpopoditiswideandshort,thedaCty0poditisslab-shaped,eachjoint'sedgehasshorthahaforswirTuning,themalebodyisbluishgreen,andthebolebodyisadeeppmple.Maleanddrileglands')locateatthedorsalordorsola…     

Impacts of sampling design on the abundance estimation of Portunus trituberculatus using crab pots

Fishery-independent surveys can provide high-quality data and support fishery assessment and management.Optimization of sampling design is crucial to increase the quality of fishery surveys.Crab pots are important fishing gears used to catch crabs.We analyzed the impacts of sampling design of crab pots on the abundance of Portunus trituberculatus in the Changjiang(Yangtze) River estuary to the Hangzhou Bay and its adjacent waters in East China Sea.The crab pots were cylindrical,240 mm in height and 600 mm in diameter of the iron ring.Our sampling designs(including fixed-station sampling,simple random sampling,stratified fixed-station sampling,and stratified random sampling),three number of stations(9,16,and 24),and three numbers of crab pots(500,1 000,and 3 000) were simulated and compared with the "true" abundance that obtained from bottom trawl survey s in the study area in 2007.The scenarios with16 stations were set in stratification as a control group for comparison with unstratified designs.Results show that simple random sampling can obtain more stable results than fixed-station sampling in the abundance estimation of P.trituberculatus.In addition,stratified sampling resulted in more accurate abundance than unstratified sampling.The accuracy of the simulated results improved with the increase of the number of stations.No remarkable differences in the re sults were found among the scenarios of different number of crab pots at each station.However,resource-intensive areas exerted great impacts on simulation results.Thus,prior information or pre-survey results about resource abundance and density distribution are necessary.This study may serve as a reference for future sampling designs of crab pots of P.trituberculatus and other species.     

Production of Pacific White Shrimp Polycultured with Swimming Crab at Different Densities,and Nutrient Budget in the Enclosure System

This study was to evaluate the effect of stocking densities on the nitrogen and phosphorus budgets for a polyculture of the crab Portunus trituberculatus and the Pacific white shrimp Litopenaeus vannamei.The shrimps(initial weight,0.012 g)were cultured at a density of 45 shrimp m^-2,and juvenile crabs(initial weight,0.024 g)were cultured at five densities of 0,3,6,9,and 12 crabs m^-2.The treatments were grouped as C0S45,C3S45,C6S45,C9S45,and C12S45,respectively.Water quality parameters,growth of shrimp and crabs,and nitrogen and phosphorus budget were measured.The results indicated that the shrimp performances in polyculture treatments C3S45 and C6S45 were superior to those in the crab-free treatment(C0S45).The crab in treatments C3S45 and C6S45 exhibited a significantly higher final mean weight and carapace width/length than those in treatments C9S45 and C12S45.The final size and survival of crabs had a negative correlation with the increasing crab stocking density.The contents of total phos-phorus and total nitrogen and the comprehensive contamination index values were higher in the C9S45 and C12S45 treatments than in the other treatments.The conversion ratios of nitrogen for crab and shrimp growth in treatment C3S45 were significantly higher than those in the crab-free treatment.These findings indicate that polyculturing shrimp with crabs at suitable densities can improve productivity,profitability,nutrient utilization,and the environmental quality.From the 60-day treatments,the optimal culture densi-ties were 3-6 crabs m^-2 and 45 shrimps m^-2.     

Monthly Variation in Crustacean Assemblage(Decapod and Stomatopod) and Its Relationships with Environmental Variables in Laizhou Bay,China

In this study,we investigated the community structure of crustaceans(decapod and stomatopod) inhabiting the sandy mud bottoms of Laizhou Bay(northeastern China) monthly from May 2011 to April 2012.Investigation was stopped from December 2011 to February 2012 because of the extreme weather and sea ice.A total of 205,057 specimens belonging to 31 species(shrimp,15;crab,15;and stomatopod,1) were collected in 148 hauls.From 2011 to 2012,Oratosquilla oratoria was the dominant biomass species(47.80%),followed by Charybdis japonica(15.49%),Alpheus japonicas(12.61%),Portunus trituberculatus(6.46%),and Crangon spp.(4.19%).Crangon spp.was the most dominant species by individual(32.55%).O.oratoria was the most-frequently encountered species(81.76%),followed by Palaemon gravieri(70.95%),C.japonica(65.54%),A.japonicas(62.16%),and P.trituberculatus(54.73%).The biomass density increased from August to September 2011 and decreased from March 2012 to April 2012.The dynamics of the ecological indices evolve in a similar manner,with high values of diversity and evenness and rich species from May to June 2011 and low values from September to October 2011.O.oratoria,C.japonica,and P.trituberculatus differed by biomass data between groups I(samples obtained from September to October 2011) and II(samples in other months).These species contributed more than 70% to the similarity of the crustacean community structure.Furthermore,the subsets of environmental variables that best matched the crustacean-assemblage structure were as follows:water depth(WD) in summer(June to August);sea surface temperature(SST),dissolved oxygen(DO),and WD in autumn(September to November);and DO,salinity,and WD in spring(March to May).The calculated correlation coefficients and significance level were higher in the period of July to August 2011 than in other months.Comparing 2011 to 2012 with 1982 to 1983,the species composition remained stable.However,the dominant species changed significantly.High value and large species,such as F.chinensis,P.trituberculatus,and T.curvirostris,have been replaced by low value and small species(i.e.,Crangon spp.,P.gravieri,and C.japonica).     

Growth,reproduction & population structure of the freshwater crabSinopotamon yangtsekiense bott, 1967, from Zhejiang,China

Monthly investigations were mae on the population of Chinese freshwater crab,Sinopotamon yangtsekiense Bott, 1967 from April, 1984 to March, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature. During the April to November growth period, the crabs' major development occurred from June through October. One year was required for a fine white oocyte to develop into a mature egg. The reproduction period was June–October. Females bearing eggs were taken from June–August, and crabs with young were found from July–October. The females reproduced once a year but could for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from 30 to 100 eggs. New-born crabs become mature after 1–2 years. The sex ratio was approximately 1∶1 in the overall population. However, the larger crabs are predominantly male. The age distribution ofS. yangtsekinese was estimated from size frequency histograms. There were more adult crabs (over 70%) from June to October and more immature crabs (over 50%) from November to May.     

Effects of Several Immunostimulants on Phenoloxidase and Hemocytes of the Crab Charybdis japonica

To investigate the stimulating effects of immunostimulants on the autogenous immunocompetence of crabs and the possible mechanisms involved, the immunostimulating effects of β-1,3-glucan, lipopolysaccharide (LPS), inactivated Vibrio harveyi and Vibrio anguillarum on phenoloxidase (PO) and hemocytes of Charybdis japonica were investigated in this study. It was found that the yields and the enzymatic activities of purified PO in C. japonica increased significantly after the crabs were treated with immunostimulants, while the unit enzymatic activities remained almost the same. After treatment with β-1,3-glucan and LPS, the amount of rough endoplasmic reticulum (RER) and the number of mitochondria in both semigranular cells and granular cells increased greatly, and the number of cytoplasmic granules decreased but with enlarged volume. However, the corresponding characteristics of hyaline cells remained almost the same. On the other hand, the number of granules in semigranular cells decreased greatly, and the number of mitochondria of hyaline cells increased greatly, after treatment with inactivated vibrios. It may be concluded that the effect of polysaccharide immunostimulants on the innate immune system of C. japonica is different from that of inactivated vibrio immunostimulants. The immunity-enhancing mechanism of polysaccharides in crab autogenous immunocompetence is probably accomplished by the increased yields of PO and total PO activities, while that of inactivated vibrios is probably accomplished by the partially increased yields of PO and total PO activities as well as the significantly improved phagocytotic abilities of semigranular cells and hyaline cells.     

Effects of several immunostimulants on phenoloxidase and hemocytes of the crab Charybdis japonica

To investigate the stimulating effects of immunostimulants on the autogenous immunocompetence of crabs and the possible mechanisms involved, the immunostimulating effects of β-1,3-glucan, lipopolysaccharide (LPS), inactivated Vibrio harveyi and Vibrio anguillarum on phenoloxidase (PO) and hemocytes of Charybdis japonica were investigated in this study. It was found that the yields and the enzymatic activities of purified PO in C. japonica increased significantly after the crabs were treated with immunostimulants, while the unit enzymatic activities remained almost the same. After treatment with β-1,3-glucan and LPS, the amount of rough endoplasmic reticulum (RER) and the number of mitochondria in both semigranular cells and granular cells increased greatly, and the number of cytoplasmic granules decreased but with enlarged volume. However, the corresponding characteristics of hyaline cells remained almost the same. On the other hand, the number of granules in semigranular cells decreased greatly, and the number of mitochondria of hyaline cells increased greatly, after treatment with inactivated vibrios. It may be concluded that the effect of polysaccharide immunostimulants on the innate immune system of C. japonica is different from that of inactivated vibrio immunostimulants. The immunity-enhancing mechanism of polysaccharides in crab autogenous immunocompetence is probably accomplished by the increased yields of PO and total PO activities, while that of inactivated vibrios is probably accomplished by the partially increased yields of PO and total PO activities as well as the significantly improved phagocytotic abilities of semigranular cells and hyaline cells.     

Analysis of DNA Methylation Level of Portunus trituberculatus Subjected to Low Salinity with Methylation-Sensitive Amplification Polymorphism

In this study, the methylation-sensitive amplification polymorphism(MSAP) was used to compare the genomic DNA methylation level of muscle, gill and hepatopancreas of Portunus trituberculatus subjected to salinity 12 for 30 days to illustrate the epigenetic mechanism of osmoregulation. Thirty primers were used to analyze the difference of methylation level of different tissues. The results showed that the baseline methylation level of muscle, hepatopancreas and gill was 47.31%, 22.94% and 17.69%, respectively. After exposed to low salinity stress, the methylation epiloci changed in the three tissues. Both demethylation and methylation processes occurred under low salinity stress. The methylation ratio decreased in muscle and gill but increased in hepatopancreas. These results indicated that DNA methylation is tissue-specific when P. trituberculatus responds to low salinity.     

Phospholipid Compositions in Portunus trituberculatus Larvae at Different Developmental Stages

Phospholipids are used to improve the growth and survival of Portunus trituberculatus,a widely cultured crab species in China.However,only total phospholipids or several classes are applied in crab diets.In this study,we employed a targeted lipidomic method to investigate the comprehensive phospholipid composition in P.trituberculatus larvae and reveal the changing phospholipid profile over the larval development.Results showed that P.trituberculatus larvae contain 112 phospholipid species belonging to 10 phospholipid classes,in which phosphatidylcholine(PC)and phosphatidylethanolamine(PE)species are the most abundant,and PC,PE,phosphatidic acid,and phosphatidylserine(PS)are with high concentrations.The levels of all phospholipids significantly changed with larval development,which was highlighted by the downward parabolic changes in PE,phosphatidylglycerol,phosphatidylino-sitol,PS,lysophosphatidic acid,and sphingomyelin levels.In addition,nearly all phospholipid species were depleted at the M stage,which probably contributed to the mass mortality of crab larvae.These findings on the composition and alterations of phospholipids in P.trituberculatus larvae provide novel perspectives for the targeted supplementation of phospholipids in crab diets.Our work also highlights the use of targeted UHPLC-MS lipidomics in understanding the changes of phospholipids during crab development.