A reovirus disease in cultured mud crab, Scylla serrata, in southern China     

Weng SP  Guo ZX  Sun JJ  Chan SM  He JG 《Journal of fish diseases》2007,30(3):133-139

A reovirus, designated mud crab reovirus (MCRV), associated with large economic losses was recently isolated from marine cultured mud crab, Scylla serrata, in southern China. The complete viral particle is 70 nm in diameter, icosahedral and non-enveloped. The virus infects connective tissue cells of the hepatopancreas, gills and intestine in mud crab and develops in the cytoplasm. Hundred per cent mortality was observed in mud crab experimentally infected by intramuscular injection, bath inoculation and oral inoculation, while cohabitation infection caused 80% mortality. The viral genome consists of 13 linear dsRNA segments, with an electrophoretic pattern 1/5/7. The results of this study suggest that the virus is highly pathogenic and can be transmitted enterically as well as via the body surface of mud crab. Although the genomic organization of this virus is different from that of the other crab reoviruses, CcRV-W2 and DpPV, all three of these reoviruses have similar electrophoresis patterns. Therefore, MCRV may be a new member of the DpPV and CcRV-W2 group.  相似文献   

饥饿对拟穴青蟹大眼幼体和Ⅰ期仔蟹蜕皮和生长的影响#br#     

胡伟胜  马春艳  马凌波  张凤英  刘志强  赵明  王伟 《海洋渔业》2022,44(1):54-66

为了给拟穴青蟹(Scylla paramamosain)苗种培育过程中饵料的合理投喂提供基础理论数据,采用投喂-饥饿和饥饿-投喂的处理方式对拟穴青蟹大眼幼体和Ⅰ期仔蟹分别开展营养储存饱和点实验(PRS)和不可恢复点实验(PNR),研究饥饿对大眼幼体和Ⅰ期仔蟹蜕皮和生长的影响。结果显示,大眼幼体的PRS实验中,投喂时间≤2 d时,大眼幼体的蜕皮率为0;投喂时间≥4 d时,大眼幼体的蜕皮率和发育时间与连续投喂组(F组)无显著性差异;但投喂4 d-饥饿组(F4S组)大眼幼体蜕皮后Ⅰ期仔蟹的增重率和个体大小均显著小于F组(P<0.05)。大眼幼体的PNR实验中,饥饿2 d时大眼幼体的存活率仅为(30.00±13.23)%。Ⅰ期仔蟹的PRS实验中,连续饥饿组(S组)Ⅰ期仔蟹的蜕皮率为0,而投喂2 d-饥饿组(F2S组)、投喂3 d-饥饿组(F3S组)和F组3组Ⅰ期仔蟹的蜕皮率均无显著性差异。投喂1 d-饥饿组(F1S组)和F2S组Ⅰ期仔蟹蜕皮后Ⅱ期仔蟹的增重率和个体大小均显著小于F组(P<0.05),且F1S组Ⅰ期仔蟹的发育时间显著延长(P<0.05)。Ⅰ期仔蟹的PNR实验中,除饥饿1 d-投喂组(S1F组)外,F组Ⅰ期仔蟹的蜕皮率显著高于其他处理组(P<0.05);各组Ⅰ期仔蟹蜕皮后Ⅱ期仔蟹的增重率与饥饿时间呈负相关,而发育时间却与饥饿时间呈正相关;饥饿时间≥2 d时,Ⅰ期仔蟹蜕皮后Ⅱ期仔蟹的个体大小明显变小。拟合分析结果显示,大眼幼体的PRS;值是3.57 d,Ⅰ期仔蟹的PRS;和PNR;值分别是0.90 d和2.01 d。研究结果表明,新蜕皮的大眼幼体必须给予充足的饵料才可确保高的存活率,大眼幼体投喂6 d后可以适当减少投喂量,短期饥饿对Ⅰ期仔蟹蜕壳和生长的影响相对较小,Ⅰ期仔蟹的耐饥饿能力强于大眼幼体。  相似文献   

青蟹的营养需求研究及其配合饲料研制     

艾春香刘建国  林琼武李少菁王桂忠  陈学雷 《水产学报》2007,31(B09):122-128

青蟹属（Scylla）有锯缘青蟹（Scylla serrata），拟穴青蟹（S．paramamosain），紫螯青蟹（S．tranquebarica）和榄绿青蟹（S．olivacea）等4个种。我国以拟穴青蟹占绝对优势，它有个体大、生长快、适应性强、肉味鲜美、营养丰富等特点，已成为具有重要经济价值的海水养殖蟹类之一。  相似文献   

Lipids and fatty acids in wild and pond-reared mud crab Scylla serrata (Forsskål) during ovarian maturation and spawning     

Veronica R Alava  Emilia T Quinitio  Jennete B de Pedro  Flora Mae P Priolo  Zenith Gaye A Orozco  & Mathieu Wille 《Aquaculture Research》2007,38(14):1468-1477

Wild‐caught and pond‐reared female mud crab Scylla serrata at different stages of ovarian maturation were collected from Samar and Capiz, Philippines. Crabs were categorized into five stages according to the external morphological and microscopic appearance of the most advanced oocytes. The ovaries, hepatopancreas, muscle and newly spawned eggs (NSE) were analysed for lipid class components and fatty acids. Total lipid was higher in pond‐reared than in wild‐caught crabs but increased with ovarian maturation in both groups. Ovarian lipid peaked at the fully mature stage, coinciding with a decline in hepatopancreatic and muscle lipids. Lipid levels declined significantly in spent females. The tissues contained elevated highly unsaturated fatty acids such as arachidonic (20:4n‐6), eicosapentaenoic (20:5n‐3) and docosahexaenoic (22:6n‐3) acids, but at higher levels in late maturing and fully mature ovaries and in NSE. The type of lipid class and fatty acid components in mature ovaries as well as in NSE are generally considered to be indicative of their importance in reproductive physiology and embryonic and larval development.  相似文献   

Status of Biological Studies and Aquaculture Development of the Mud Crab, <Emphasis Type="Italic">Scylla serrata</Emphasis>, in China: An Experimental Ecological Studies     

Wang?Gui-zhongEmail author  Li?Shao-jing  Zeng?Chao-shu  Lin?Shu-jun  Kong?Xiang-hui  Ai?Chun-xiang  Lin?Qiong-wu 《Aquaculture International》2005,13(5):459-468

This is an initial paper in a series of overviews of biological research and aquaculture development of the mud crab, Scylla serrata, in China. Results of experimental ecological studies on mud crabs are reported here. As a result of these experimental studies, results that are important for mud crab culture were also discovered and these include, methods to condition and manage broodstock, determination of ecological conditions that are suitable for embryonic development, and the influence of temperature, salinity, diet and larval density on development and survival of larvae. Results of this work will be useful in establishing a good method for artificial mass culture of larvae.  相似文献   

锯缘青蟹促雄腺发育的组织学研究   总被引：3，自引：1，他引：3       下载免费PDF全文

叶海辉  李少菁  黄辉洋  王桂忠  林琼武 《中国水产科学》2003,10(5):376-380

采用组织切片技术，以OlympusBH-2型显微镜对锯缘青蟹(Scylla serrata)促雄腺的发育进行观察。结果显示，促雄腺附着于射精管近末端，发育过程可分为4期：Ⅰ期促雄腺短小，腺细胞数量少；Ⅱ期促雄腺呈明显的索状；Ⅲ期促雄腺体积达到最大，一些部位膨大增生；Ⅳ期促雄腺不再生长，腺体急剧退化。腺细胞具有2种类型：A型细胞，核圆、异染色质少、胞质染色浅；B型细胞，核扁平、异染色质多，细胞染色深、界限不清晰，有时细胞质消失。促雄腺发育过程中，A、B型细胞数量、比例发生变化。B型细胞为A型细胞完成分泌后的存在形式，B型细胞比例反映了促雄腺分泌活动的状况。锯缘青蟹促雄腺发育和精巢成熟具有一定的相关性。  相似文献   

Assessment of dietary lecithin and cholesterol requirements of mud crab, Scylla serrata, megalopa using semi-purified microbound diets   总被引：1，自引：0，他引：1  

M.-H. HOLME  P.C. SOUTHGATE  & C. ZENG 《Aquaculture Nutrition》2007,13(6):413-423

The effects of varying dietary lecithin and cholesterol levels on growth, development and survival of mud crab, Scylla serrata, megalopa were evaluated using six semi‐purified, microbound diets formulated to be iso‐energetic and containing three levels of supplemental lecithin (0, 20 and 40 g kg⁻¹ diet dry weight) and two levels of supplemental cholesterol (0 and 7 g kg⁻¹ diet dry weight). Fifteen megalopa were reared individually in each treatment and the nutritional value of diets was assessed on basis of mean dry weight and mean carapace width of newly settled first crab stage, as well as development time to the first crab stage and overall survival. A significant interaction between supplemental dietary lecithin and supplemental dietary cholesterol was found for final mean dry weight of newly settled crabs, and highest survival (60%) was recorded for megalopa fed diets containing the highest levels of dietary lecithin (39.7–44.1 g kg⁻¹) (diet 5 and 6) regardless of whether diets were supplemented with cholesterol; this rate of survival was identical to that of megalopa fed live Artemia nauplii. The results indicate that supplemental dietary cholesterol may not be essential for mud crab megalopa when fed diets containing sufficient levels of supplemental dietary phospholipids.  相似文献   

锯缘青蟹亲蟹选择及培育技术     

夏连军  王建钢  施兆鸿  黄聪年 《海洋渔业》2003,25(4):189-191

亲蟹质量及亲蟹培育是锯缘青蟹人工育苗的基础。本文就亲蟹的选择、亲蟹暂养期的环境、亲蟹的饵料及饲养条件进行了探讨。在相同的理化因子条件下,海捕亲蟹的抱卵率(62.13％)大约为养殖亲蟹抱卵率(26.67％)的2.31倍。  相似文献   

Development of nursery culture techniques for the mud crab Scylla paramamosain (Estampador)     

Vu Ngoc Ut  Lewis Le Vay  Truong Trong Nghia  & Tran Thi Hong Hanh 《Aquaculture Research》2007,38(14):1563-1568

Cannibalism is one of the main causes of mortality in the culture of the mud crab Scylla paramamosain, particularly in the early post‐larval and juvenile stages when the densities of hatchery‐reared crabs may be very high before stocking into ponds or release into the wild for stock enhancement. In a series of experiments investigating cannibalism mitigation, the influence of stocking density, the effectiveness of sand substrate, brick and shell shelters and feed type were compared in culture of crabs from instar 1 for short nursery periods of 15–30 days. Inclusion of brick and shell shelters significantly increased survival over sand substrate alone. However, inclusion of shelters did not affect growth rates. In scaled‐up nursery production in lined‐ponds, with shelters, live Artemia biomass and fresh chopped shrimp or tilapia were found to be equally effective feeds for juvenile crabs stocked at a density of 70 m⁻² from instar 1 and grown for 30 days [52–66% survival, 21.6–24.6 mm carapace width (CW)]. In an extended nursery period for a further 30 days, crabs of 22 mm CW, stocked at 30 m⁻² in the same ponds, attained a final size of 34.5–36.2 mm CW with a survival of 64.3–67.0% using the same feeds.  相似文献   

江蓠与新对虾、青蟹混养试验   总被引：12，自引：2，他引：12       下载免费PDF全文

王焕明  李少芬  陈浩如  王肇鼎 《水产学报》1993,17(4):273-280

细基江蓠繁枝变种与新对虾，青蟹混养试验结果表明：（１）细基江蓠繁枝变种生长的最适温，盐度分别为１７－３０℃和１７－２９‰，这一温，盐度范围也适合新对虾和青蟹的生长；鱼塘海水的温，盐度变化与沿海不同，因此，移植野生江蓠到鱼塘养殖时要考虑这一特点。（２）江蓠在不同的生长季节的最适生长水层是不同的。（３）江蓠的主要有效氮是ＮＨ４＾＋，而新对虾，青蟹的排泄物可分解出大量的ＮＨ４＾＋。这样，江蓠与新对虾，青  相似文献