我国蟹类土池育苗技术研究进展

蟹类养殖产业已成为我国水产养殖的支柱产业之一。中华绒螯蟹(Eriocheir sinensis,以下简称河蟹)、三疣梭子蟹(Portunus trituberculatus,以下简称梭子蟹)、拟穴青蟹(Scylla paramamosain,以下简称青蟹)是我国主要的养殖蟹类。目前3种蟹类土池育苗技术发展不平衡,河蟹、梭子蟹土池育苗技术较为成熟,已经普及推广并在养殖生产中发挥重要作用;青蟹土池育苗尚未有成功的报道。本文综述了我国河蟹、梭子蟹、青蟹苗种生产技术,尤其是土池育苗技术的研究进展,并对河蟹、梭子蟹土池育苗关键技术进行分析,旨在探讨蟹类土池育苗技术应用于青蟹土池育苗的可行性。     

环境胁迫与河蟹体色

池塘养殖的河蟹体色往往不如湖泊围网养殖的河蟹。河蟹体色取决于甲壳中虾青素浓度。河蟹自身不能合成虾青素,必须从饲料或饵料中获取。因此河蟹体色差的主要原因是不能从外界获得足够的虾青素。虾青素具有抗氧化作用。环境胁迫导致的氧化应激也会消耗虾青素。低溶氧、高pH、水温、氨氮、重金属胁迫均可引起河蟹氧化应激。因此,改善池塘河蟹体色不仅要增加青虾素的供应,还要加强养殖管理,降低环境因子的胁迫。     

中华绒螯蟹养殖与固城湖水体氮、磷相关性研究

近年来固城湖水环境质量日益恶化的现象呈现明显,为寻求固城湖水环境质量污染原因,本文将利用物料平衡原理,建立氮磷总量的数学模型,计算固城湖中华绒螯蟹养殖每年所产生的氮磷量,经与实测结果验证,该模型是合理可行的。采用Spearman秩相关系数法计算得到,固城湖中华绒螯蟹养殖所产生的氮、磷量与固城湖大湖区、港口和河口的氮、磷量具有明显的相关性。说明固城湖中华绒螯蟹养殖可导致固城湖水体的氮磷总量呈现快速增长。为更好地保护固城湖水生态环境,应严格控制中华绒螯蟹养殖的规模,杜绝中华绒螯蟹养殖产生的有机污水直接排放入固城湖。     

中华绒螯蟹种质研究进展

总结我国在中华绒螯蟹形态学、养殖性能、细胞遗传学、生化遗传学及分子遗传学方面的种质研究的主要成果 ,归纳中华绒螯蟹不同种群在形态、细胞、生化、分子等层次上的遗传差异。在形态学研究方面 ,运用形态多元分析 ,建立不同种群绒螯蟹从幼蟹到成蟹的量化判别函数 ;在生化遗传和分子遗传研究方面 ,找到中华绒螯蟹区别于其他绒螯蟹的生化遗传标记和分子遗传标记 ,以及中华绒螯蟹不同种群由南到北的分子遗传渐变标记 ;在养殖性能方面 ,阐明中华绒螯蟹不同种群在幼蟹和成蟹阶段的养殖性能 (包括蜕壳、生长、性腺发育、性成熟及生殖洄游等 )差异和特点     

沉水植物对中华绒螯蟹生长和非特异性免疫力的影响

从东太湖采集伊乐藻(Elodea canadensis)、金鱼藻(Ceratophyllum demersum)、轮叶黑藻(Hydrilla verticilla-ta)、苦草(Vallisneria natans)、马来眼子菜(Potamogeton malaianus)5种沉水植物分别制成干粉。在基础饲料中添加15%的干粉形成5种不同的配合饲料,分别饲喂体重为(9.37±0.15)g的中华绒螯蟹(Eriocheir sinensis)60 d,分析沉水植物对中华绒螯蟹生长和非特异性免疫力的影响。结果显示:马来眼子菜组的中华绒螯蟹平均增重率显著低于对照组(P<0.05),饲料系数显著高于对照组(P<0.05),其余4种沉水植物组的平均增重率和饲料系数与对照组无显著差异(P>0.05);各组成活率、肥满度及肝体比差异不显著(P>0.05)。沉水植物各组的蟹血清超氧化物歧化酶活力显著高于对照组(P<0.05);与对照组相比,轮叶黑藻组、伊乐藻组和苦草组的中华绒螯蟹血清溶菌酶活性显著升高(P<0.05),金鱼藻组和马来眼子菜组则差异不显著(P>0.05);除马来眼子菜组降低外,其余4种沉水植物组中华绒螯蟹对嗜水气单胞菌的抵抗力强于对照组。因此,除马来眼子菜以外的4种沉水植物对中华绒螯蟹的生长性能无明显的促进作用,但可在一定程度上提高其非特异性免疫力。     

显微介导河蟹总DNA导入镜鲤的检测与分析

利用显微介导远缘杂交技术将河蟹总DNA直接导入镜鲤受精卵内,再利用AFLP分子标记技术检测显微介导河蟹基因镜鲤的外源DNA。在30对AFLP引物中,有3对引物扩增出供体基因片段,即在显微介导河蟹基因镜鲤中均有和河蟹基因相同而对照镜鲤没有的条带。对6尾阳性显微介导河蟹基因镜鲤的扩增产物进行回收、克隆和测序验证。结果表明:阳性显微介导河蟹基因在镜鲤中均含有供体基因目的片段。本研究在分子和基因水平上验证了河蟹总DNA可通过显微介导方式整合到镜鲤基因组中,为显微介导外源总DNA转化技术的应用提供新的思路。     

不同交配,越冬方式对河蟹育苗的影响

不同交配、越冬方式对河蟹育苗产量有着显著的影响，三年的生产实践表明：秋季室外土池交配的抱卵率、抱卵量明显高于水泥交配；秋季交配优于春季交配；室外土池自然越冬抱卵卵蟹的胚胎发育优于室外塑料大棚保温越冬的抱卵蟹。适宜的秋，春交配有利于河蟹多苗育苗，延长生长期，增加产量。     

虫草培养基残余体在中华绒螯蟹饲料中的适宜添加量

在基础饲料中分别添加0.25%、0.5%、1.0%、2.0%、4.0%、8.0%、16.0%的虫草培养基残余体(简称虫草基),饲喂规格为(4.0±1.0)g的中华绒螯蟹(Eriocheir sinensis)75 d,通过测定其生长及非特异性免疫指标,以确定虫草基的适宜添加量。结果显示:与基础饲料组比较,0.5%和1.0%添加组平均增重率(WGR)、肥满度(CF)、成活率(SR)显著提高(P<0.05),饲料系数(FC)显著降低(P<0.05);除肥满度(CF)外,4.0%、8.0%、16.0%添加组的生长指标有所下降。低剂量虫草基添加组能提高中华绒螯蟹血淋巴及肝胰腺超氧化物歧化酶(SOD)、溶菌酶(LSZ)、酸性磷酸酶(ACP)、碱性磷酸酶(ALP)活性,其中,0.5%与1.0%添加组的SOD、LSZ、ACP和ALP水平均达显著水平(P<0.05);但当虫草基添加量超过2.0%时,中华绒螯蟹的非特异性免疫力逐渐下降。嗜水气单胞菌(Aeromonas hydrophila AHJ-1)攻毒试验证实,试验组的免疫保护率明显提高,0.5%添加组免疫保护率达100%。综上所述,虫草基作为中华绒螯蟹饲料添加剂的适宜添加量为0.5%～1.0%。     

伊乐藻对中华绒螯蟹生长和营养品质的影响

本研究分析了有伊乐藻(Elodea nuttallii)组和对照组(无伊乐藻)中华绒螯蟹(Eriocheir sinensis)在生长、肌肉氨基酸和脂肪酸组成等方面的差异,探讨伊乐藻对中华绒螯蟹生长和营养品质的影响。结果显示,有伊乐藻组中华绒螯蟹体重、壳长和壳宽增长率与肥满度均显著高于无伊乐藻组(P0.05),但肝胰腺指数和性腺指数差异不显著(P0.05)。伊乐藻组中华绒螯蟹肌肉的氨基酸总量、必需氨基酸和鲜味氨基酸含量均显著高于无伊乐藻组(P0.05);伊乐藻组的雌蟹肝胰腺中的鲜味氨基酸含量也显著高于无伊乐藻组(P0.05),而伊乐藻组和无伊乐藻组的雄蟹肝胰腺氨基酸含量差异不显著(P0.05)。伊乐藻组和无伊乐藻组的中华绒螯蟹肌肉脂肪酸组成和含量差异不显著(P0.05),但伊乐藻组中华绒螯蟹的肝胰腺饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)和多不饱和脂肪酸(PUFA)含量均显著高于无伊乐藻组(P0.05)。综上所述,伊乐藻不仅有利于中华绒螯蟹的生长,而且能改善中华绒螯蟹的营养品质。     

河蟹溞状幼体培育期使用孔雀石绿杀灭聚缩虫的试验

孔雀石绿对河蟹(氵蚤)状幼体的48小时半数致死浓度Ⅰ期幼体为1.89ppm,V期幼体为7.45ppm。在河蟹工厂化育苗中如果发生聚缩虫感染,可采用孔雀石绿1ppm浓度全池泼洒、10～12小时内排出药液水、技入新水的方法杀灭聚缩虫,不会影响河蟹(氵蚤)状幼体的变态发育。     

不同增养殖水体中华绒螯蟹一般营养成份比较分析

实验对不同增养殖水体中华绒螯蟹可食部分一般营养成分营养指标进行分析研究,结果显示在中华绒螯蟹成熟的10月,粗蛋白雌、雄蟹分别为19.48%、16.17%,与其他甲壳类水产动物蛋白质含量相当,粗脂肪雌、雄蟹为13.21%、10.91%,显著高于其他甲壳类水产动物。粗蛋白、粗脂肪含量雌蟹大于雄蟹,水份、灰份雌蟹小于雄蟹。不同增养殖水体10月份中华绒螯蟹粗蛋白含量呈现养殖水体(湖泊网围、池塘养殖)大于增殖水体(湖泊放流、长江野生)态势。     

Identification of SNPs in the 5′‐flanking region and 3′‐UTR of the MIH gene and their association with precocity of the Chinese mitten crab Eriocheir sinensis

Moult‐inhibiting hormone (MIH), an important regulator of steroidogenesis, inhibits the synthesis of ecdysteroid in Y‐organ (YO) and plays a significant role in the regulation of moulting and post‐embryonic development of crustacean. Because unsuccessful moulting have been widely observed in precocious crabs, we investigated whether genetic variants in the 5′‐flanking region and 3′‐untranslated region (3′‐UTR) of the MIH gene are associated with precocity of the Chinese mitten crab. Thirty individual DNA samples were sequenced to search for SNPs in the 5′‐flanking region and 3′‐UTR of the MIH gene. Five SNPs (g.196 T>A, g.230 C>T, g.305 T>C, g.323 C>A and g.372 C>T) in the 5′‐flanking region and 6 SNPs (g.2677 C>T, g.2759 T>A, g.2807 T>C, g.3042 A>G, g.3088 T>G and g.3295 T>G) in the 3′‐UTR of the MIH gene were selected for the individual genotyping in a two‐stage association study. We found that a SNP g.3088 T>G in the 3′‐UTR of MIH gene was consistently associated with precocity of the Chinese mitten crab in stage 1 and stage 2, with a per‐allele OR (Odds Ratio) of 1.469 (95% CI: 1.169–1.844) after two stages combined (P = 0.001). However, no significant associations were observed between the other 10 SNPs and precocity of the Chinese mitten crab. To our best knowledge, this is the first association study between various SNP genotypes and phenotype attributes in Chinese mitten crab. Our findings suggest that the SNP g.3088 T>G may be a candidate marker for effective marker‐assisted selection to decrease the precocity of the Chinese mitten crab in future studies.     

Purification and characterization of a new reovirus from the Chinese mitten crab, Eriocheir sinensis

A new reovirus was recently isolated from a freshwater crab, the Chinese mitten crab, Eriocheir sinensis, in China. The complete viral particles are 55 nm in diameter, icosahedral, non-enveloped and have a mean buoyant density of 1.39 g cm(-3) in CsCl gradient. The viral genome is composed of 12 pieces of dsRNA with an electrophoretic pattern of 3/4/2/3. This virus infects connective tissue of the gills, gut and hepatopancreas. Partial cDNA cloning and sequence analysis showed that the RNA-dependent RNA polymerase is located in the first RNA segment. From its biochemical, ultrastructural and physicochemical properties, this virus is quite different from the genus Aquareovirus (Reoviridae). It may represent a new genus of Reoviridae, different from the other crab reoviruses, P and W(2).     

中华绒螯蟹副性征的研究

在解剖、测量性成熟和未成熟中华绒螯蟹外部形态和性腺之基础上,试用“双百分率法”和“差异显著性检测法”对中华绒螯蟹的副性征进行了研究。结果表明,性成熟后的雌、雄中华绒螯蟹均具有较明显的副性征。     

中华绒螯蟹２个幼蟹群体形态性状与体重的关系

对中华绒螯蟹(Eriocheir sinensis)2个幼蟹群体的头胸甲长(壳长)、头胸甲宽(壳宽)、第Ⅳ步足节长与体重性状进行了测定,通过简单相关分析、偏相关分析和回归分析,初步确定了与中华绒螯蟹幼蟹体重相关的外部形态性状,比较了2个群体头胸甲比例的差别,为中华绒螯蟹的选育提供理论依据和测度指标。结果表明,所测各表型性状与体重之间的相关系数均达到极显著水平(P<0.01);其中,人工苗壳长与体重的相关性最大,天然苗则是壳宽与体重的相关性最大;分别建立了以形态性状估计人工苗、天然苗群体体重的最优回归方程。从外形比例分析,天然苗的头胸甲近似方形,人工苗的头胸甲近似椭圆形。     

中华绒螯蟹胚胎发育及几种代谢酶活性的变化

采用实验室内小规模实验的方法,在水温(16.2±1.5)℃和盐度20的条件下,对中华绒螯蟹胚胎发育过程中的形态学变化和几种重要代谢酶的活性变化进行了系统性研究。实验结果表明,中华绒螯蟹的胚胎发育过程可以分为9个主要阶段:受精卵、卵裂期、囊胚期、原肠期、前无节幼体期、后无节幼体期、原溞状幼体期、出膜前期和孵化期;水温16℃的条件下,整个胚胎发育过程需40 d左右,有效积温达到10 758 h.℃。乳酸脱氢酶(LDH)、总ATPase和苹果酸脱氢酶(MDH)的活性都随胚胎发育时期的变化而变化,LDH活性呈现出先上升后下降的趋势,在囊胚期中活性最高;总ATPase活性在原溞状幼体期最高,在原肠期最低;MDH活性在原溞状幼体期最高,在囊胚期最低。     

中华绒螯蟹种苗静水土池塘培育技术研究Ⅲ——室内育苗和土池育苗经济效益和生态效益的比较

用１０００ｍ３水体的室内育苗池和６口海水土池塘（计１９ｈｍ２）培育中华绒螯蟹（Ｅｒｉｏｃｈｅｉｒｓｉｎｅｎｓｉｓ）苗,比较两种河蟹人工繁殖技术的生态效益和经济效益。经３５天培育表明,土池培育１ｋｇ大眼幼体可获利２０６３元,比室内育苗获利（３９３元）高４２倍;产出投入比（２０７）比室内育苗（１３３）高４５７７％。若采用土池育河蟹苗,每年至少可以少排放各种化学药物４２０ｔ。     

Mitochondrial DNA variation and population structure of the Japanese mitten crab Eriocheir japonica

ABSTRACT:   The Japanese mitten crab Eriocheir japonica is a common grapsid species found throughout freshwater and estuarine regions in Japan. In order to obtain information on the genetic variation and population structure of this species, a polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) analysis was conducted on the cytochrome oxidase subunit I (COI) of mitochondrial DNA, on 666 individuals from 19 sample sites covering the three main geographic regions of Japan (Main Islands, Okinawa, and Ogasawara). Genetic analysis using seven restriction enzymes produced an array of 61 composite haplotypes. Three regional groups corresponding to the three geographic regions were clearly identified by cluster and molecular variance model ( amova ) analyses. Each of the three groups showed dominant haplotypes that were almost completely absent in populations from the other geographic areas. Comparison with published information for other species indicates that the degree of genetic divergence between these three main groups is equivalent to the genetic distance between congeneric species. Thus, the population structure of the Japanese mitten crab, as inferred from mtDNA analysis, is formed by genetically distinct groups that closely reflect their geographic distribution in the Japanese archipelago as well as restricted gene flow.     

Economic evaluation of mud crab farming under different production systems in India

Abstract

Apart from penaeid shrimp culture, crab farming and fattening and other several diversified aquaculture practices are now emerging as viable ventures in India. About 11 types of crab products are being exported from India with an average unit value realization of US$ 3.73 kg^?1, pinpointing its importance in the foreign exchange earnings. An economic evaluation of mud crab culture, fattening and fattening with composite culture of shrimp/finfish has been attempted in this paper. The major operating cost was that of seed and it was higher for crab fattening (87% of the total operating cost). Feed costs were very low compared to that of shrimp farming. Annual profit obtained was US$ 22812.5 ha^?1 year^?1 for culture and US$ 30820.8 ha^?1 year^?1 for fattening. Economic indicators such as net profit, rate of return, pay back period and breakeven price indicate that crab fattening/culture is much more profitable than any other coastal aquaculture operations currently in practice, provided hatchery production is established in the country to ensure adequate supply of mud crab seeds.