草鱼出血病细胞培养灭活疫苗的研究——疫苗株的免疫原性及其有效免疫剂量的比较

本文比较了疫苗株FR—854和FR—836—w的免疫原性,及其对三寸左右草鱼种的有效免疫剂量。疫苗株FR—854和FR—836—w均有较强的免疫原性,其保护力可达70%以上。但试验结果初步证明,FR—854疫苗比FR—836—w疫苗免疫原性更强。经统计分析,FR—854疫苗的免疫保护力可达88.9±12.0（6）%,血清中和抗体效价为160.5±58.9（6）;而FR-838-W疫苗分别只有71.3±14.2（6）%、88.3±26.2（6）;二者有显著的差异（0.05>P>0.01）。注射免疫三寸左右的草鱼种,FR—854的免疫剂量在3—5×10^4.5TCID0/尾左右,FR—836—w在3—5×107.5TCID₅₀/尾左右,其免疫保护力可达80%左右,同时我们测得ER—854的半数免疫量为10^5.1TCID₅₀/ml。     

特异化饵料免疫预防草鱼出血病的生产性试验

草鱼出血病是一种病毒性鱼病，它严重影响着草鱼的成活率，尤其是对一龄草鱼种的危害。目前比较有效的防治方法是将出血病疫苗注射到鱼体使其获得后天的免疫保护力，但这种注射法需要一尾一尾地进行，费工费时还易损伤鱼体，对当年草鱼和大规模的鱼种生产难以应用。因此，研究更简便、有效的免疫途径是预防草鱼出血病迫切需要解决的课题。我们于１９９６～１９９８年用草鱼出血病细胞疫苗处理的特异化饵料，在草鱼苗开口期投喂，完成疫苗接种。经室内攻毒测定，对草鱼出血病的免疫保护力可达９０％以上，免疫后的草鱼血清抗体凝集价显著高于…     

集里村山塘种草养鱼高产试验总结

1992年,浏阳市畜牧水产局在本市集里乡集里村进行山塘种草养鱼高产试验,现将试验情况总结如下: 1 山塘条件山塘面积8亩,水深2m,淤泥深60cm左右,无水源。 2 鱼种放养所投鱼种一部分自留,一部分从本地购进。放养时草鱼均进行免疫注射,再用3％的食盐水浸洗10分钟,共投放草、鲢、鳙等鱼种5740尾,1330kg。其中草鱼种4000尾,900kg,占总放养量的67.7％。套养草鱼寸子2000尾,加州鲈夏花200尾。 3 饲养管理 3.1 投饵:鱼种从冬季下塘起投喂精料。2—5月中旬以投喂黑麦草为主;6—10月份投喂苏丹草、禾苗及灌浆的青稻谷苗,同时辅以精料。日投2—3次,投料在3     

8903浸泡免疫的免疫性试验

水温控制在２０℃以上时，草鱼种浸泡免疫后第１５天成活率达９６．３％，保护力高达９４．１％，对２００尾２．６ｃｍ左右的草鱼种进行中间免疫试验，成活率平均９２．６％。８９０３浸泡免疫草鱼种免疫期可长达１６个月，比注射免疫长２－３个月。     

学习辩证法 一养到底培育大鱼种

我场有苗种培育池180亩，亲鱼培育池30亩(兼套养鱼种)。为了养出大鱼种，促进商品鱼生产的发展，我们针对本省鱼苗生产晚，培育期短的特点，从1967年开始全面采取一养到底的饲育方法。几年来，通过不断的实践、认识，培育技术有所提高。一般每年都生产出秋片鱼种150—170万尾，出池鱼种有70—80％达到8寸以上，其中鲢、鳙鱼约半数达到3．5寸以上。苗种池平均每亩育成鱼种7，000—9，000尾，全期培育成活率50％左右。     

灭活疫苗 预防出血病真灵

郴州市郴江乡龙门池村渔民谢玉昌,1987年3月12日用省水产所制造的草鱼免疫疫苗,采用胸腔注射方法,共注射17—33厘米的草鱼种300尾,放于一口水面2.5亩的成鱼塘中,经8个多月精心饲养,于当年11月30日干塘,共捕获2公斤左右的草鱼292尾,成活率高达97.3％。与往年相比,有如下优点: 1、成活率提高,成鱼均重增加。 1986年在同一口鱼塘中放养同样规格的草鱼种300尾,最后统计全年仅捕捞草鱼240尾,死亡60尾,成活率为80％,且均重只有1.5公斤左右。据此,1987年比86年提高成活率17.3％,草成鱼的平均体重增重0.5公斤左右。 2、成本降低,劳动强度减少。往年,由于没有注射疫苗,每年均用漂白粉、敌百虫等鱼药,药费开支16.7元,同时,下塘泼药,上山找草药,使劳动强度增大;1987年注射疫苗以后,只是零星     

流水培育鱼种初获成效

我县万坳公社笆蕉水库的职工发扬敢闯敢干的精神，利用仅有的四口鱼池(面积共3亩6分)流水培育草、鲢水花210万尾(放养密度每亩达到58．3万尾)，出池6分～2寸鱼种120万尾，出池率达到57．1％．     

90％晶体敌百虫驱杀草鱼鱼种阶段肠道寄生虫——毛细线虫的初步试验

毛细线虫病系青、草鱼鱼种阶段的一种比较常见的疾病。在此种寄生虫少量寄生时(每尾感染1—3条)不致引起死亡，但在大量寄生时(每尾感染30—50条)则可引起鱼种的大量死亡。1963年在我县仙女垸养殖场的鱼种池内曾因此病的危害而死亡青鱼鱼种(1．2—1．4寸)达50余万尾，1974年我们又发现鱼种池内毛细线虫对火片草鱼种有不同程度的感染。据统计患此病的鱼池占全部鱼池的21．7％。针对当时情况，我们采用90％晶体敌百虫(上海农药厂出品)拌和面粉制成药饵，     

解决成鱼箱投放老口草鱼种的途径

近几年,我市网箱养鱼发展迅速,取得了明显的经济效益和社会效益,已成为农民致富的一条生产门路。但老口草鱼种的自给率较低,是发展网箱养鱼的重要制约因素之一。因此必须重点抓好老口草鱼种的培育配套工作,以确保网箱养鱼的持续稳定发展。笔者就怎样解决成鱼箱投放老口草鱼种的途径,谈谈粗浅的看法。一、首先自育好1龄草鱼种每个网箱养鱼户都要有0.2亩左右面积的鱼池,在家孵季节,每亩放养草鱼苗10万尾左右;或四月底、五月初每亩晚稻秧田放养草鱼苗1万尾左右,通过40来天的强化培育,鱼苗迅速长到6cm左右,然后将其放入早稻田(每亩放养2000尾左右)或育种箱里(每m~2放养300—500尾)     

8903浸泡草鱼种免疫生产性试验

1990—1991年连续两年对夏花草鱼种进行了8903浸泡免疫生产性试验。1990年设试验池两个,面积共0.44 ha,1991年也设试验池两个,面积0.56公顷,两年各设对照池1个。鱼池水深控制在1.5 m左右,溶氧都在5 mg/L以上,pH值为7.5—8.0,试验期不投喂青饲料,以投喂人工配合饲料为主。两年试验结果表明,生产性鱼池8903浸泡免疫草鱼种,免疫效果与室内浸泡免疫效果一致,能使草鱼产生较强的保护力,保护力达80％以上,免疫持续时间达16个月,能控制住草鱼出血病流行两个高峰期,无论是夏花鱼种或是一冬龄草鱼种,都能对其产生较高的免疫力,其达72％—80％。     

网箱养鱼高产试验及其技术因子的探讨

本文报导了网箱养殖莫桑比克罗非鱼(Tilapia mossambica)和草鱼(Ctenopharyngodon idellus)高产试验。其中网养莫桑比克罗非鱼获得每平方米净产97公斤，饲料系数为2．16：网养草鱼每平方米净产14．5公斤，饲料系数为2．49。此外，本文论述了网箱结构，饲养环境，养殖方式，饲料配方，投喂技术等技术因子对提高单位产量的关系。作者认为合理选择网箱，敷设饲料台，控制溶氧不低于3mg／L、水温不低于15℃，饲养密度为5—10公斤／米^2，单养，采用蛋白质组分不低于35％的颗粒饲料以及提供10％-2％的日给食率，是网养给食式鱼类获得高产并降低饲料系数的关键。     

Ammonia nitrogen excretion in Mandarin Fish (Siniperca chuatsi) and Grass Carp (Ctenopharyngodon idellus) fed practical diets: the effects of water temperature

To understand the actual production of fish culture about the utilization of dietary protein and excreta impact on the environment between mandarin fish (Siniperca chuatsi) and grass carp (Ctenopharyngodon idellus), the study to investigate the effect of temperatures (19 ± 0.5°C, 24 ± 0.5°C and 29 ± 0.5°C) on ammonia‐N excretion in mandarin fish and grass carp under fed and fasted states was conducted. These two species were fed a practical diet containing 325.2 g kg^?1 crude protein at 3% body weight per day. The ammonia‐N excretion rate was significantly increased when temperature increased from 19 to 29°C, and a linear relationship between ammonia‐N excretion rate and temperature. The maximum ammonia‐N excretion levels of mandarin fish and grass carp were observed at 4–8 h and 2–4 h after feeding, respectively, and the minimum values for both species were observed at 24 h after feeding. Under the feeding condition, mandarin fish had a lower ammonia‐N excretion level compared to grass carp at 24°C and 29°C. The average amount of ammonia‐N excreted by mandarin fish at 24 h is significantly higher than grass carp under fasting conditions, except 19 ± 0.5°C. These results indicated that mandarin fish might make better use of protein at higher temperature than grass carp when fed practical diets in commercial production. These results of this study suggested that mandarin fish had a lower ammonia‐N excretion level compared with grass carp, making a less contribution to environmental loading in an intensive fish culture.     

Purification and characterization of glucose 6-phosphate dehydrogenase (G6PD) from grass carp (Ctenopharyngodon idella) and inhibition effects of several metal ions on G6PD activity in vitro

Glucose 6-phosphate dehydrogenase (G6PD) is a key enzyme catalyzing the first step of the pentose phosphate pathway which generates NADPH for anabolic pathways and protection systems in various organisms, including fish. In the present study, G6PD was purified from grass carp (Ctenopharyngodon idella) hepatopancreas using the methods of 2′,5′-ADP-Sepharose 4B affinity chromatography followed by DEAE Sepharose Fast Flow ion exchange chromatography. The characterization of G6PD and inhibition effects of several metal ions on G6PD activity in vitro were also determined. Grass carp hepatopancreas G6PD, with a specific activity of 18 U/mg protein, was purified 1,066-fold with a yield of 19.5 % and Mr of 71.85 kDa. The enzyme had a temperature optimum of 42 °C, pH optimum of 7.5 and 9.0. The K _m values for G6-P and NADP⁺ were determined to be 0.026, 0.0068 mM, respectively. The V _max values for G6-P and NADP⁺ were 2.20 and 2.27 μM min^?1 mg protein^?1, respectively. The catalytic efficiency for G6-P and NADP as the substrates was 0.085 and 0.334 × 10^?6 min^?1 mg protein^?1, respectively. Inhibition effects of metal ions on the purified G6PD activity indicated that IC₅₀ values of Zn⁺², Mn⁺², Al⁺³, Cu⁺², and Cd⁺² were 0.42, 0.54, 0.94, 1.20, and 4.17 mM, respectively. The Ki constants of Zn⁺², Al⁺³, Cu⁺², and Cd⁺² were 0.52, 1.12, 0.26, and 4.8 mM, respectively. Zn⁺², Al⁺³, and Cd⁺² showed competitive inhibition, while Cu⁺² inhibited the G6PD in a noncompetitive inhibition manner. Our study provided important information about the control of the grass carp liver PPP, the biosynthesis of several important related biomolecules, and the status of detoxification systems in grass carp liver in relation to metabolism.     

Cloning and molecular characterization of cationic amino acid transporter y+LAT1 in grass carp (Ctenopharyngodon idellus)

The solute carrier family 7A, member 7 gene encodes the light chain- y⁺L amino acid transporter-1 (y⁺LAT1) of the heterodimeric carrier responsible for cationic amino acid (CAA) transport across the basolateral membranes of epithelial cells in intestine and kidney. Rising attention has been given to y⁺LAT1 involved in CAA metabolic pathways and growth control. The molecular characterization and function analysis of y⁺LAT1 in grass carp (Ctenopharyngodon idellus) is currently unknown. In the present study, full-length cDNA (2,688 bp), which encodes y⁺LAT1 and contains a 5′-untranslated region (319 bp), an open reading frame (1,506 bp) and a 3′-untranslated region (863 bp), has been cloned from grass carp. Amino acid sequence of grass carp y⁺LAT1 contains 11 transmembrane domains and shows 95 %, 80 % and 75 % sequence similarity to zebra fish, amphibian and mammalian y⁺LAT1, respectively. The tissue distribution and expression regulation by fasting of y⁺LAT1 mRNA were analyzed using real-time PCR. Our results showed that y⁺LAT1 mRNA was highly expressed in midgut, foregut and spleen while weakly expressed in hindgut, kidney, gill, brain, heart, liver and muscle. Nutritional status significantly influenced y⁺LAT1 mRNA expression in fish tissues, such as down-regulation of y⁺LAT1 mRNA expression after fasting (14 days).     

草鱼出血病病毒854株基因组SDS—PAGE分析及其核酸类型鉴定

十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)结果表明:草鱼出血病病毒854株基因组由11个分段的核酸片段组成,总分子量约为14.46×10~6道尔顿。其中最大片段的分子量约为2.45×10~6道尔顿;最小片段的分子量约为0.38×10~6道尔顿。其基因组核酸片段电泳图谱具有病毒株的特异性.核酸酶敏感性试验表明该病毒的核酸为RNA。     

Dietary potassium requirement of juvenile grass carp (Ctenopharyngodon idella Val.) based on growth and tissue potassium content

A growth trial was conducted to estimate the optimum concentration of dietary potassium (K) for grass carp (Ctenopharyngodon idella). Triplicate groups of grass carp (3.96 ± 0.06 g) were fed diets containing graded levels (0.87, 2.90, 5.37, 7.54, 9.87 and 12.4 g kg^?1) of K for 8 weeks. Final body weight, weight gain and feed efficiency and gill Na⁺‐K⁺ ATPase activity were highest in fish fed with 9.87 g kg^?1 dietary K and lowest in fish fed the basal diet (P < 0.05). The K contents in whole body and muscle were linearly increased up to the 9.87 g kg^?1 dietary K and then levelled off beyond this level, whereas in scales and vertebrae up to the 7.54 g kg^?1 dietary K (P < 0.05). However, dietary K levels had no significant effect on ash, Ca, P and Mg contents in whole body, scales, vertebrae or muscle. Analysis using polynomial regression of weight gain and gill Na⁺‐K⁺ ATPase activity and using the broken‐line regression of whole body K concentrations indicated that the adequate dietary K concentration for grass carp is about 9.45–9.99 g kg^?1 diet.     

草鱼养殖水体中参与氮转化途径的异养菌分析

为分析草鱼池塘中参与氮代谢的异养细菌比例及其代谢途径,从杭州郊区取得4个草鱼池塘的水样,每个水样通过涂布随即挑选100株菌株进行定性显色试验,并据此选取11株异养菌进行16S rRNA序列分析。结果表明,4个草鱼养殖池塘中NH4+-N和NO2--N的平均水平分别为5.597 mg/L和0.135 mg/L。池塘中可培养的异养菌平均为3.26×105cfu/mL,其中的89.75%参与了氮的不同代谢途径,其中31.25%的氨化菌和33.50%NO3--N(NO2--N)还原菌参与了NH4+-N的生成,32.45%的氨氧化菌参与了NH4+-N的降低;NO2--N生成途径主要包括蛋白质直接转化(11.26%)、氨氧化(4.25%)和硝酸盐氮还原(10.75%),而NO2--N降低主要通过15.50%的亚硝酸氧化菌、8.75%的NO2--N还原菌和10.75%的反硝化菌实现。结果提示,草鱼养殖水体中存在大量的异养硝化菌参与不同的氮代谢途径,且产生氨氮的异养菌比例远高于去除氨氮的菌,这是草鱼养殖水体中氨氮含量易偏高的原因。同时,11株不同功能的异养菌16SrRNA鉴定结果为寡养食单胞菌(Stenotrophomonas)6株、假单胞菌(Pseudomonas)3株、克雷伯氏菌(Klebsiella)和肠杆菌(Enterobacter)各1株,而且细菌对氮源的利用具有菌株特异性。     

Protein‐sparing capability of dietary lipid in herbivorous and omnivorous freshwater finfish: a comparative case study on grass carp (Ctenopharyngodon idella) and tilapia (Oreochromis niloticus × O. aureus)

Two, 8‐week feeding trials were conducted to compare protein‐sparing capability of dietary lipid in herbivorous grass carp (Ctenopharyngodon idella) and omnivorous tilapia (Oreochomis niloticus × O. aureus). Utilizing a 2 × 3 factorial design, experimental diets containing two levels of crude protein (380 and 250 g kg⁻¹) and three levels of lipid (0, 40 and 100 g kg⁻¹) were formulated for use in both feeding trials. Growth performances showed better response of both fish fed 380 g kg⁻¹ protein diet than those fed 250 g kg⁻¹ protein diet. Despite the dietary protein level, weight gain (WG), specific growth ratio (SGR), feed conversion ratio (FCR) and protein efficiency ratio were much higher (P < 0.05) for grass carp fed 40 g kg⁻¹ lipid diet than those fed 100 g kg⁻¹ lipid diet; however, there were no significant differences in tilapia fed the two diets. The feed intake of grass carp fed lipid‐free diet was the lowest, but it tended to decrease with increase in dietary lipids in tilapia. Lipid retention (LR) was negatively correlated with dietary lipid concentration of both fish. Viscerosomatic index (VSI), hepatosomatic index (HSI), intraperitoneal fat ratio (IPF) and whole‐body and liver lipid content positively correlated with dietary lipid concentration of both fish. Plasma parameters and liver enzymes activities were also positively correlated with dietary lipid concentration of both fish. Liver lipid contents were higher and enzymes activities were lower in grass carp when compared with tilapia. These data suggested that there was no evidence of a protein‐sparing effect of dietary lipids in grass carp. Tilapia has relatively higher capacity to endure high dietary lipid level compared to grass carp.     

The use of synthetic LH-RH analogue to spawn Chinese carps *

Abstract. The synthetic LH-RH analogue, des-GLY¹⁰[D-Ala⁶] LRH ethylamide was shown to be effective for induced spawning of Chinese carps. Ovulation was induced in 23 of 34 female grass carp, Ctenopharyngodon idella Val., receiving a single injection of synthetic LH-RH analogue. Spawning success was 92% for 3-year and older fish at optimum temperatures (22–26°C). Reduced spawning success was noted for 2-year-old female fish, and when temperature exceeded 27°C. No mortality of study fish was observed following a single injection. Hybrid carp, grass carp x bighead carp, Aristichthys nobilis Val., and grass carp x silver carp, Hypophthal-michthys molitrix Val., were produced using synthetic LH-RH analogue. Male grass carp, bighead carp and silver carp exhibiting pearl organs were stimulated to produce milt regardless of the presence or absence of free flowing milt at the time of injection. The potential importance of synthetic LH-RH analogue in fish culture and mechanisms of hormonal action are briefly discussed.