罗氏沼虾幼体及仔虾消化酶活力的研究

以酶学分析方法对罗氏沼虾幼体及仔虾4种消化酶的活力进行研究。结果表明：罗氏沼虾早期个体消化酶类胰蛋白酶、胃蛋白酶和脂肪酶比活力均为蚤状幼体I朗(Z1)＜蚤状幼状IV期(z4)＜蚤状幼体x期(Zlo)＜仔虾I—Ⅱ期(PI—Ⅱ)，各期的类胰蛋白酶比活力明显低于胃蛋白酶；淀粉酶比活力为z＜P期，在pH值2—9．8的范围内，蛋白酶活性出现2个高峰分别为pH2．6—3．2和pH5．6—6．25淀粉酶最适pH值为5．2—5．8，呈弱酸性。     

罗氏沼虾幼体暂养技术

育苗场出售的罗氏沼虾苗,其规格一般在0.8～1.0cm,直接入塘养成,其成活率较低,成虾规格偏小。特别是北方地区,养成时间短,商品虾规格小,直接影响了经济效益。如有条件暂养1个月左右,将虾苗培养成1.5～3.0cm的幼虾后再入塘养成,可大大提高成活率,成虾个体也较大,可提早上市,提高经济效益。 幼体暂养有室内水泥池暂养。塑料大棚暂     

罗氏沼虾幼体暴发性疾病药物防治

罗氏沼虾（Macrobrachiumrosenbergii）具有生长快、养殖周期短、个体大、经济价值高等特点，是一种优良的淡水养殖对象。目前，罗氏沼虾在我国已形成规模性生产，罗氏沼虾工厂化育苗也已取得显著成绩，但在育苗过程中常因病害引起大批幼虾死亡，经济损失严重。1996年3－5月间苏州地区多个育苗场的Ⅱ－Ⅲ期及Ⅺ期的罗氏沼虾幼体先后出现暴发性死亡。作者在研究其病原体的同时，进行了抑菌试验，筛选有效药物，并进行治疗试验，以求尽快找到有效的防治方法。l方法l．l病情调查1996年3－－5月间对吴江市特种水产养殖公司和吴县市养殖总场的罗…     

氨氮对罗氏沼虾幼体的影响

非离子态氨氮对罗氏沼虾幼体毒性试验结果表明，罗氏沼虾幼体２４小时半致死的ＮＨ３－Ｎ浓度值为４．１０９毫克／升左右，１００％死亡的ＮＨ３－Ｎ值为５．０６１毫克／升；４８小时ＮＨ３－Ｎ的ＬＣ５０值范围为１．０１５－２．１１２毫克／升，ＬＣ值为３．１２７毫克／升；生产池中的ＮＨ３－Ｎ值较低，对罗氏沼虾幼体的生长蜕壳没有什么明显的不利影响。     

罗氏沼虾幼体疾病的防治

介绍了罗氏沼虾幼体在培育期间所患的“幼体病”、细菌性坏死病、蜕皮障碍病、体表寄生微生物病的发病情况及症状、病因、防治方法     

罗氏沼虾幼体发育及生活习性观察

罗氏沼虾幼体刚从卵孵出时呈潘状，称溞状幼体。这是罗氏沼虾整个生命周期中唯一在咸淡水中度过的生活阶段。在此期间，幼体要求一定的盐度、温度、饵料和氧量等，才能完成多次蜕皮，变态成幼虾。因此，观察幼体阶段不同发育时期的形态特征，研究它的生活习性，以便提供适宜的生活环境条件，这对提高幼体质量，提高幼体培育成活率具有重大的实践意义。     

罗氏沼虾蚤状幼体培育试验

培育出健壮的苗种，提高其成活率是进行罗氏沼虾养殖的重要环节。我所l977年8月，引进罗氏沼虾，1978年春人工繁殖成功，4年来共培育淡化虾苗208万余只(表1)。本文着重总结1981年幼体培育主要技术环节。     

不同来源罗氏沼虾幼体的育苗对比试验

2010年2月,对采自江苏吴江、广西三塘和广西南宁国家级良种场共3种不同来源的罗氏沼虾(Macrobra-chium rosenbergii)进行从幼体阶段至变态苗阶段的培育试验;干量容积法推算产苗量,计算育苗成活率。试验结果表明,3种不同来源幼体的育苗成活率分别为73.6%、65.2%和90.4%,成活率差异明显;其中,国家级广西南宁罗氏沼虾良种场的育苗成活率最高。在育苗生产中,必须注重罗氏沼虾亲本的种质复壮与培育,才能保证幼虾的质量,有利于提高其养殖成活率。     

不同来源罗氏沼虾幼体的培育对比试验

2010年2月,对采自江苏吴江、广西三塘和广西南宁国家级良种场共3种不同来源的罗氏沼虾（Macrobra-chium rosenbergii）进行从幼体阶段至变态苗阶段的培育试验;干量容积法推算产苗量,计算育苗成活率。试验结果表明,3种不同来源幼体的育苗成活率分别为73.6%、65.2%和90.4%,成活率差异明显;其中,国家级广西南宁罗氏沼虾良种场的育苗成活率最高。在育苗生产中,必须注重罗氏沼虾亲本的种质复壮与培育,才能保证幼虾的质量,有利于提高其养殖成活率。     

Identification and partial characterization of selected proteolytic enzymes in the digestive system of giant freshwater Prawn Macrobrachium rosenbergii (De Man) Postlarvae

Biochemical assays and substrate SDS-PAGE were conducted to partially characterize and identify various types of proteases present in the digestive tract of PL₁₅ giant freshwater prawn ( Macrobrachium rosenbergii ). Casein hydrolytic assay of the enzyme extracts showed major proteolytic activities at pH 3.0, 6.0 and 9.0, while assay of preincubated enzyme extracts with phenylmethylsulphonyl fluoride (PMSF), a serine protease inhibitor produced a 33.17% reduction in alkaline protease activity. When specific inhibitors tosyl-lysine chloromethyl ketone and tosyl-phenylalanine chloromethyl ketone were used, they resulted in a reduction in activity of proteases in the enzyme extracts by 82.41% and 55.03%, respectively, confirming the presence of trypsin and chymotrypsin, while ethylenediamine tetraacetic acid produced protease activity reduction in 33.92% showing the presence of metalloproteases in the digestive tract of the prawn. Further characterization of the alkaline proteases using SDS-PAGE technique, after incubating the extract in the presence or absence of specific inhibitors, produced six bands corresponding to molecular masses of between 13.48 and 136.1 kDa; two trypsin bands of 13.48 and 36.4 kDa, three chymotrypsin bands in the range of 23.0–73.4 kDa and one for metalloprotease of 136.1 kDa, all of which were identified from a zymogram. This study suggests that protein digestion in M. rosenbergii is initiated by an acid protease followed by a combination of action of alkaline proteases: trypsin, chymotrypsin and metalloproteases.     

水解鸡血珠蛋白部分替代鱼粉对罗氏沼虾生长、体组成和消化酶活性的影响

为探讨水解鸡血珠蛋白部分替代鱼粉对罗氏沼虾(Macrobrachium rosenbergii)幼虾(初重2.10±0.06 g)生长、体组成和消化酶活性的影响,试验用水解鸡血珠蛋白分别替代鱼粉0%(BC₀,对照组)、10%(BC₁₀)、30%(BC₃₀)和50%(BC₅₀)制成4种等氮(粗蛋白37.86%)等脂(粗脂肪8.77%)的试验饲料,开展9周的养殖试验。结果显示:利用水解鸡血珠蛋白替代鱼粉对罗氏沼虾存活率无显著性影响。当替代量为10%时,生长性能和饲料效率未受显著性影响,但肌肉中粗蛋白含量显著高于对照组。当替代量为30%和50%时,生长性能和饲料效率显著低于对照组,肌肉中的粗蛋白含量与对照组无显著差异。所有替代组肌肉中必需氨基酸和总氨基酸的含量均显著高于对照组,且肝胰腺胰蛋白酶的活力显著高于对照组。此外,所有替代组肌肉中粗脂肪含量均显著高于对照组,且BC₁₀和BC₃₀组肝胰腺脂肪酶活力亦显著高于对照组。以上结果表明,利用水解鸡血珠蛋白替代10%的...     

Growth and digestive enzymes of Macrobrachium rosenbergii juveniles: effect of different stocktypes and dietary protein levels under a similar culture environment

A feeding trial was conducted to study the effect of dietary protein (DP) levels on the growth and digestive enzyme activities of different wild stocks of Macrobrachium rosenbergii juveniles. Wild juveniles of M. rosenbergii were collected from the west coast of India, Gujarat (G), Maharashtra (M) and from the east coast of India, Andhra Pradesh (A), and raised in culture ponds of 200 m² at 1 juvenile m^?2. All the animals were tagged individually with Elastomer tags of a particular colour assigned to their respective stock and acclimatized for 7 days before being released into the pond at a ratio of 70:65:65 (A:M:G). Each of the two feeds, the first with 27% DP, termed the suboptimum level (S), and the second 32% DP, termed the optimum level (O), was fed in duplicate ponds at 6% of the body mass for the first 30 days and 4% for the last 30 days. The average weight of stocked prawn, respectively, in O DP and S DP fed ponds was 0.90 ± 0.04 and 1.06 ± 0.08 g for the G stock, 0.80 ± 0.07 and 1.01 ± 0.1 g for the M stock and 3.06 ± 0.13 and 3.10 ± 0.23 g for the A stock. Both the protein level and the stock type had a significant (P<0.05) effect on the weight gain% of the prawn. There was an approximate 95% change in weight gain with a DP change. Similarly, G and M stocks exhibited significantly higher (P<0.05) growth rates of approximately 90% than the A stock, although no difference was noted between the G and the M stocks. However, for protein × stock (interaction) levels, there was no significant difference (P>0.05) among the groups. Although insignificant, the survival rates among the different stocks varied from 56% to 77%. Optimum protein level showed a significant increase (P<0.05) in the specific growth rate (SGR). Feed conversion ratio, feed efficiency ratio, protein efficiency ratio and net protein utilization were not affected either due to DP, stock type or their interaction. The O × A group exhibited the maximum variation in body weight. Digestive enzyme activities were similar in all the groups, but enzymes for phospho‐monoesterase were significantly higher (P<0.05) at O DP. Both the G and the M stock showed a significantly higher (P<0.05) alkaline phosphatase activity while acid phosphatase activity was significantly higher (P<0.05) in the M stock only. Overall, the G and M stocks showed higher growth responses compared with the A stock.     

罗氏沼虾育苗期抑菌药物试验

在罗氏沼虾工厂化育苗期间，用２ｍｇ／Ｌ浓度的高锰酸钾溶液浸浴幼体，可以在短时间内有效抑菌，用１ｍｇ／ｍｌ的土霉素溶液浸浴幼体，能有效抑菌。通过酸试验，高锰酸钾和土霉素的抑菌效果与ＰＨ的降低相关性不强。     

生物絮团对罗氏沼虾体组成和消化酶活性的影响

通过向养殖水体中泼洒糖蜜构建生物絮团养殖模式,分析生物絮团营养组成,并探讨生物絮团对罗氏沼虾体组成和消化酶活性的影响。试验分对照组和试验组(生物絮团组),其中试验组在养殖过程中泼洒糖蜜。试验在室内水泥池内(2 m×2 m×0.6 m)进行,每个处理有3个重复,每个重复225尾虾(0.26 g±0.02 g),试验周期为90 d。养殖过程中不换水,糖蜜的泼洒量根据饲料投喂量进行计算(C/N为20)。结果显示:添加糖蜜能够显著促进生物絮团的形成,到第90天时,试验组的絮团体积达21.22 mL/L;而对照组为6.03 mL/L;试验组絮团粗蛋白含量为29.47%,粗脂肪含量为4.32%,二者均显著高于对照组,而粗灰分含量为11.36%,显著低于对照组;泼洒糖蜜对罗氏沼虾体组成的影响不显著,对照组和试验组肌肉粗蛋白含量分别为21.09%和21.20%,粗脂肪含量分别为2.91%和3.06%;另外,向水体中泼洒糖蜜对罗氏沼虾消化酶活性影响显著。试验组罗氏沼虾肠脂肪酶活性、胃脂肪酶活性和胰脂肪酶活性均显著高于对照组;试验组罗氏沼虾糜蛋白酶活性、胰蛋白酶活性也均显著高于对照组。但泼洒糖蜜对肠淀粉酶、胃蛋白酶、胃淀粉酶、胰淀粉酶和纤维素酶活性没有显著影响。试验表明,生物絮团营养组成丰富,能够有效提高消化酶活性。     

罗氏沼虾冷冻调理品的开发利用

对罗氏沼虾（Ｍａｃｒｏｂｒａｃｈｉｕｍｒｏｓｅｎｂｅｒｇｉ）冷冻调理品的加工方法和保鲜技术进行了研究。试验结果表明,加工后的罗氏沼虾,其保藏性能增强,加添加剂后罗氏沼虾的鲜度下降明显减慢。     

罗氏沼虾苗种肌肉白浊病诺达病毒的分离和特性研究

本实验在以往罗氏沼虾(Macrobrachium rosenbergii)苗种肌肉白浊病病毒致病性的基础上对病毒特性进行深入研究。病虾除菌过滤液以1：50和1：250浸泡感染可复制出典型的症状，病毒对氯仿抵抗；用PEG法浓缩病毒后，35000r／min超速离心部分纯化病毒，在电镜下可观察到大量直径24nm的球形病毒颗粒，无囊膜，此外还观察到大小为14nln的病毒粒子；采用Trizol试剂对病毒进行了核酸提取，电泳结果发现有4条核酸条带，分别为3．0kb、1．3kb、0．8kb、0．75kb，对RNA核酸酶、S1核酸酶敏感，对DNA酶抵抗．为单链RNA病毒。用罗氏沼虾诺达病毒核酸探针进行分子杂交，探针可与提纯核酸及病虾样品匀浆液反应，Southern杂交表明3．0kb、1．3kb条带分别属于诺达病毒的RNAl和RNA2。对不同的发病样品进行了核酸电泳，4个典型症状的样品均存在诺达病毒条带，2个样品还存在小病毒核酸。上述结果表明，诺达病毒是引起罗氏沼虾苗种肌肉白浊病的主要病原。14nm小病毒与罗氏沼虾肌肉白浊病中的关系有待进一步的研究。