采用受精卵消毒法进行南美白对虾人工育苗的试验

2002年5－6月，在南美白对虾人工育苗过程中，采用对受精卵和育苗用水进行消毒处理的方法，试验组平均成活率为37.69%，对照组平均成活率仅为20.42%。试验结果表明：采用受精卵消毒法，可以减少育苗期间疾病的发生，是提高南美白对虾育苗成活率的有效手段。     

Changes in lipid class and fatty acid composition of adult male Litopenaeus vannamei (Boone) in response to culture temperature and food deprivation

The effects of culture temperature and food deprivation on lipid class and fatty acid composition of adult male Litopenaeus vannamei (Boone) were investigated. Shrimp were maintained in recirculating seawater systems at temperatures of 26 and 32°C and fed 75% dry commercial feed and 25% fresh‐frozen squid for 42 days. Additionally, groups of fed and non‐fed shrimp were maintained at 26°C for 17 days. In shrimp fed at either 26 or 32°C, polar lipids were the main constituents of total identified lipid classes in muscle tissue (66–71%), while neutral lipids were more abundant in hepatopancreas (82–88%). Higher levels of triglycerides were observed in lipids of shrimp hepatopancreas kept at 32°C, but no other lipid class was affected by temperature. A significantly higher proportion of 22:6n‐3 was consistent in muscle and hepatopancreas polar and neutral lipids of shrimp maintained at 26°C. In response to food deprivation, the amount of polar lipids, but not neutral lipids, was reduced by approximately 28% in muscle tissue, whereas all lipid reserves were almost depleted in the hepatopancreas. The variable consumption of some individual fatty acids was observed in polar and neutral lipids of both tissues.     

南美白对虾幼虾饲料蛋白质的需要量

以酪蛋白和明胶为主要蛋白源,配制成蛋白质质量分数分别为28%、33%、38%、43%和48%的5种精饲料,分别在盐度2和28的水体中,对南美白对虾(Penaeusvannamei)幼虾进行49d的饲养试验。虾苗平均体重为(0 011±0 001)g,每天投喂4次。结果表明,饲料系数、蛋白质效率均随饲料蛋白质含量的增加而减小,饲料蛋白质水平对南美白对虾幼虾肌肉游离氨基酸和肝胰腺胰蛋白酶的活性有显著的影响。在盐度2的水体中,26.7%饲料蛋白质水平最适宜;在盐度28的水体中,33.0%饲料蛋白质水平最适宜。说明在一定范围内,低蛋白高能量饲料可以取得更高的蛋白质利用率以及更好的对虾养殖效果。     

Survival of White Spot Syndrome Virus–Infected Litopenaeus vannamei Fed with Ethanol Extract of Uncaria Tomentosa

With the present project, the phytochemical composition of Uncaria tomentosa cultivated in Chapecó (Brazil) was analyzed and then the potential of using this local plant extract to protect by oral feeding virus‐infected Litopenaeus vannamei shrimp was also investigated. For this study, five treatments were tested: uninfected shrimp fed with pelleted feed (T_C), WSSV‐infected shrimp fed with pelleted feed (T₁), infected shrimp fed with pelleted feed with 1% ethanol extract of U. tomentosa (EEUT) (T₂), infected shrimp fed with pelleted feed with 2% EEUT (T₃), and infected shrimp fed pelleted feed with 4% EEUT (T₄). The chemical analysis of EEUT showed the presence of alkaloids, flavonoids, sterols, terpenes, coumarins, and tannins and also a high in vitro free radical‐scavenging activity as well as high total phenolic content. Shrimp fed with 2 and 4% EEUT (T₃ and T₄) showed a survival probability significantly higher than T₁ and T₂ treatments and no clinical symptoms of WSSV infection. Immunological assay also showed a positive phenoloxidase activity effect on shrimp fed with EEUT.     

饲料中添加谷胱甘肽对凡纳滨对虾肝胰腺抗氧化指标和脂质过氧化物含量的影响

采用1种对照饲料和5种添加不同水平还原型谷胱甘肽（GSH）（添加量分别为60、120、180、240和300 mg·kg-1）的试验饲料,饲喂初始体重约为1.12 g的凡纳滨对虾（Litopenaeus vannamei）,分别命名为G0、G60、G120、G180、G240和G300组,经8周饲养后,观察饲料中不同浓度的GSH对凡纳滨对虾生长性能、肝胰腺抗氧化指标和脂质过氧化物含量的影响。结果表明,南美白对虾的增重率随着饲料中GSH添加量的增加而增加,在G180组达到高峰,但随着GSH添加量的进一步增加,增重率呈下降趋势（P<0.05）;饲料转化率随饲料中GSH添加量的升高而显著升高,在G240组达到最高（P<0.05）;成活率随饲料中GSH添加量的增加而显著提高,提高幅度为8.53%~31.69%。饲料中添加GSH能不同程度地提高凡纳滨对虾肝胰腺中抗氧化酶活力（P<0.05）,其中G60、G120组的谷胱甘肽还原酶,G120、G180和G300组的超氧化物歧化酶,G120、G180和G240组的谷胱甘肽过氧化物酶活力,分别显著高于对照组G0（P<0.05）。各试验组肝胰腺中GSH含量和总抗氧化能力比对照组G0分别提高了8.93%~52.57%和3.02%~37.03%,且呈剂量――效应关系。对虾肝胰腺中的活性氧含量随着日粮中GSH添加量的增加呈现下降的趋势,其中G180、G240组显著低于对照组（P<0.05）;与对照组相比,试验各组肝胰腺丙二醛含量显著降低（P<0.05）,抗O2-能力升高,在G120、G180、G240和G300组达到显著水平（P<0.05）。研究结果初步表明,饲料中添加一定量的GSH能提高凡纳滨对虾生长性能和肝胰腺抗氧化能力并降低脂质过氧化物含量。表4参18     

南美白对虾精养虾池放养密度试验

在连江进行南美白对虾精养虾池放养密度试验,通过水质测定,生长测定和效益分析等方面寻找能取得最好效益的适宜放养密度。研究表明:除了溶解氧与对虾放养密度成反比外,COD、PO_4-P、NO_2-N、NO_2-N、NH_4-N等水质指标均与放养密度无关,只是随着养殖时间延长,COD、PO_4-P逐渐增加。研究还表明:放养密度与对虾的体长、体重成反比,而与饵料系数成正比。养殖结果显示:在适当的条件下,提高放养密度可以增加单位面积的产量和产值。     

凡纳滨对虾血蓝蛋白的细菌凝集活性

以凡纳滨对虾（Litopenaeaus vannarnei）为研究对象，运用亲和层析、PAGE、SDS-PAGE、Western-blotting和细菌凝集实验等方法探索凡纳滨对虾血蓝蛋白的细菌凝集活性。结果发现，血蓝蛋白对副溶血弧菌（Vibrio parahaemolyticus）、溶藻酸弧菌（Vibrio alginolyticus）、河弧菌（Vibrio fluvialis）、哈维氏弧菌（Vibrio harveyi）、嗜水气单胞菌（Agromona hydrophila）和金黄色葡萄球菌（Stphylococcus aureus）等6种虾类致病菌具有凝集活性，其凝集活性大小为0．27-1．08mg／L，其中对副溶血弧菌和溶藻酸弧菌凝集活性最大，是哈维氏弧菌的4倍。在此基础之上，选取α-D-葡萄糖、D-半乳糖、D-木糖、D-山梨糖、蔗糖、麦芽糖、α-D-乳糖、甘露醇和N-乙酰神经氨酸等9种糖考察其对血蓝蛋白细菌凝集活性的影响。结果显示，血蓝蛋白的细菌凝集活性可被α-D-葡萄糖和N-乙酰神经氨酸所部分抑制和全部抑制，其最低抑制浓度范围为50～100mmol／L。由此推测，血蓝蛋白确实具有细菌凝集活性，这对进一步研究血蓝蛋白的抗菌机理具有重要意义。     

壳寡糖对南美白对虾生长和血清生化指标的影响

为研究壳寡糖对南美白对虾(初始体重约1.23 g)的生长和血清生化指标影响,设置了含壳寡糖0 mg/kg、125 mg/kg、250 mg/kg、500 mg/kg、1000 mg/kg的5组试验饲料,经过8周的饲养实验。结果表明,不同含量的壳寡糖对南美白对虾的增重率、特定生长率、饲料系数和成活率均无显著影响(P>0.05);对南美白对虾血清中的肌酐、葡萄糖、钙离子、总胆固醇、甘油三脂和低密度脂蛋白胆固醇均无显著影响,但可使高密度脂蛋白胆固醇显著增加,促进脂类代谢;综合试验结果得出饲料中壳寡糖添加250~500 mg/kg为宜。     

包膜硫酸钠/过氧化氢/氯化钠加合物对南美白对虾养殖水体的增氧效果

以过氧化氢、硫酸钠和氯化钠为主要原料,制备包膜硫酸钠/过氧化氢/氯化钠加合物。对加合物的表层结构、稳定性能和释放性能进行分析,结果发现:该加合物颗粒表层为松散的大孔状膜,在空气中敞开放置10 d后包膜加合物分解率只有1.23%,在pH值为6.0,7.0,8.5和10.0的水中5m in内过氧化氢释放率均大于50%。将该物质分别按1.0、2.0、3.0 g/m3的用量投放在南美白对虾养殖池塘中,10 m in后,3个试验池水体溶氧分别比起始状态提高11.6%,18.2%和26.2%,约20 m in溶氧达到最大值,分别比相同时刻对照池高出27.5%,32.5%和40%,相同时刻水体溶氧随投放量的增加而升高;对照池在试验开始后约20 m in南美白对虾浮头,投放量为1.0 g/m3的试验池约60 m in后有少量南美白对虾浮头,另两个试验池一直未见南美白对虾浮头。     

Comparison of different types and levels of commercial soybean lecithin supplemented in semipurified diets for juvenile Litopenaeus vannamei Boone

Two 6-week growth trials were conducted to determine the dietary phospholipids (PL) requirement of Litopenaeus vannamei juveniles and to compare the effect of different types of soybean lecithin on shrimp growth and survival. In the first trial, a basal diet and diets containing 1.5, 3 or 5% (dry-weight basis) of Type I lecithin (97.6% PL) and 1.5 or 3% of Type II lecithin (71.4% PL) were evaluated. In the second trial, the basal diet and diets containing 1, 2 or 4% of either Type I or Type II lecithin and 1 or 2% of Type III lecithin (48.4% PL) were evaluated. Results showed that there was no interaction between lecithin type and PL level on shrimp growth or survival. Shrimp growth increased with PL levels up to 3–5% of diet. No significant differences were observed for instantaneous growth rate (IGR) of shrimp fed the different types of lecithin at the same inclusion level, and no effect of PL level and lecithin type on shrimp survival was found. Thus, the recommended level of PL supplementation in diets for L. vannamei juveniles ranges from 3 to 5% of diet.