棉酚对罗非鱼（Oreochromisniloticus）离体精子毒性作用的研究

新鲜采取的尼罗罗非鱼精液在加入棉酚的精子保存液中28℃下培养。高达10mM 的乙酸棉酚也不影响精子在一小时内的存活率。罗非鱼精子的存活率在培养三小时后存活率显下降，而低浓度棉酚（25－100μM）显提高罗非鱼精子的 存活率。 本对上述实验结果进行了讨论。     

棉酚对金鱼、罗非鱼的毒性作用初探

用乙酸棉酚含量为１‰的鱼粉饲料分别饲喂性成熟的金鱼和二月龄尼罗罗非鱼。四个月后，试验组金鱼、罗非鱼与对照组鱼在体重增长、饲料效率、特定生长率、性腺重及性重比（性腺重／鱼体重）方面的差异不明显，表明饲料中棉籽饼水平的棉酚含量（０．０３％～０．０５％），既不影响这两种鱼的正常摄食和生长，也不影响其正常的性成熟和繁殖。     

不同养殖模式对尼罗罗非鱼（Oreochromis niloticus）生长、免疫性能及水质的影响

为探讨循环水养殖模式(RAS组)和池塘养殖模式(池塘组)对尼罗罗非鱼生长、免疫性能及水质影响的变化规律,开展了为期8周的养殖试验。结果表明：(1)RAS组中鱼体增重率(WGR)(597.36±169.79)显著高于池塘组(470.98±142.99)(P < 0.05),但饲料转化率(FCE)(1.17±0.02)却显著低于池塘养殖系统(1.47±0.03)(P < 0.05)。特定生长率(SGR)和肥满度(CF)也高于池塘养殖系统,但差异不显著(P > 0.05);(2)在第4周和第8周分别测定了鱼体胃和肠中消化酶活性显示,第4周时,RAS组中肠蛋白酶活性值(1387.56±278.43)显著高于池塘组(1129.99±382.67)(P < 0.05);第8周时,肠脂肪酶活性(18.11±4.28)显著高于池塘组(12.89±8.00)(P < 0.05);(3)在第4周和第8周分别测定了鱼体肝胰脏、头肾和血清中碱性磷酸酶(ALP)、溶菌酶 (LSZ)和总超氧化物歧化酶(T-SOD)活性,显示整体上RAS组免疫性能低于池塘组;(4)每周测定水体氨态氮和亚硝态氮含量显示,RAS组氨态氮维持在0.0067 ~ 0.0212 mg / L区间内,亚硝态氮含量位于0.0027 ~ 0.0087 mg / L范围内,均低于池塘组。     

尼罗罗非鱼的生殖生态

<正> 在日本,尼罗罗非鱼苗种是在池塘里以自然繁殖方式进行生产的,对于其产卵期和产卵情况基本还未弄清。为了有计划地进行苗种生产,首先必须详细了解其性腺成熟周期和产卵期。     

氯化胆碱对尼罗罗非鱼生长影响的对比试验

<正> 胆碱(choline)是动物营养的必要成份,作为甲基的供体产生乙酰胆碱,在生理上起着各种重要的作用.1985年我们分别在室内外进行氯化胆碱对尼罗罗非鱼生长影响的对比试验。试验是以生长比速、饲料系数、脂肪蓄积率及蛋白质利用率为评定指标。三次试验结果表明,对照组比胆碱组稍好,但两者差异不显著(p>0.05)。可以认为在本试验条件下,饲料中胆碱含量已满足尼罗罗非鱼生理上的需要,没有添加氯化胆碱的必要。     

饲料中添加维生素对尼罗罗非鱼生长的影响

本试验是以酪蛋白、马铃薯淀粉等组成的精制饲料。在65天饲养试验中所得结果表明,饲料中添加混合维生素对尼罗罗非鱼的生长、食欲及饲料效率等都有显著影响,其平均增重率快30％左右,饲料消耗降低25％。饲料中不添加混合维生素,但与青饲料结合投喂也能起到与添加混合维生素相同作用。     

尼罗罗非鱼五品系生长性能评估

在我国黄河流域,长江流域及珠江流域三个农业生态区,山东青岛,上海,浙江湖州及广州四个地区,在网箱,水泥池及池塘三种水体,单养或混养系统里,对五个尼罗罗非鱼品系,即吉富品系,“７８”吕系,“８８”品系,“埃及”品系以及“美国”品系,进行生长性能的评估。评估分一龄和二龄阶段跟踪进行,共十七个试验。生长性能试验结果证明,不论是在青岛,湖州,上海还是在广州不论是池塘、水泥池,还是网箱养殖,不论是混养还是养     

鱼类特异性代谢物对草鱼、鳙和尼罗非鲫耗氧率的影响

以草鱼、鳙和尼罗非鲫互为供体和受体,研究其特异性代谢物对耗氧率的影响。结果表明：①在草鱼“代谢水”中,草鱼耗氧率显著下降（P＜0．001）,鳙和尼罗非鲫耗氧率均显著上升（P＜0．001）;②鳙“代谢水”中,鳙耗氧率显著下降（P＜0．001）,草鱼耗氧率无显著变动（P＞0．05）;③在尼罗非鲫“代谢水”中,3种鱼的耗氧率均无显著变动（P＞0.05）。实验揭示了鱼类特异性代谢物对代谢影响的存在,且这种影响因种而异。     

RELEVANCE OF A RAPID APPRAISAL APPROACH TO IDENTIFY LOCALLY AVAILABLE FEED INGREDIENTS TO SMALL-SCALE NILE TILAPIA (Oreochromis niloticus L.) AQUACULTURE

Applications of a rapid appraisal approach to identify locally available feed ingredients in feed formulation, production, and socio-economics of Nile tilapia aquaculture in Bangladesh are discussed. Three diets of 35%, 30%, and 25% crude protein were formulated using locally available ingredients, and their essential amino acid profiles were assessed for Nile tilapia. Six production scenarios were constructed using these diets and two culture periods of 100 and 150 days were considered. The production scenarios with 35% protein yielded the highest productivity and profitability over the 150-day culture period followed by the 30% protein scenario. Identification of locally available ingredients and their application in small-scale Nile tilapia aquaculture may lead to: (1) increased availability of inexpensive sources of fish production for poor people; (2) increased fish consumption; (3) increased self employment and involvement of women in productive activities; and (4) increased household income to reduce poverty.     

尼罗罗非鱼摄食器官胚后发育生物学

采用显微解剖，石蜡切片，光镜的扫描电镜观察等方法，系统观测全长６．０－２２３．０ｍｍ尼罗罗非鱼标本２７８尾，描述了口径，鳃耙，口腔上腭，颌齿，咽齿等摄食器官的形态学特点和量性胚后发过程中的变化规律；论述了尼罗罗非鱼的摄方式和摄食机能，摄食器发育与摄食方式的转化，摄食器官数量性状发育与适口食物规格和食物组成的转变，摄食器官发育与饲养生物学技术措施。为制定培育尼罗罗非鱼苗种和饲养食用鱼生物学技术措施提     

尼罗罗非鱼腐皮病致病菌的研究

尼罗罗非鱼的细菌性腐皮病是一种比较严重的疾病，感染率可达80％以上。本文对尼罗罗非鱼腐皮病的致病细菌的分离及毒力试验结果作了报道，并对这种细菌的形态、培养特性、生理生化等性状作了较详细的描述，确定其病原为Ⅰ型嗜水产气单孢菌嗜水亚种(Aeromonas hydrophila subsp.hydrophila biotype I.)     

不同品系尼罗罗非鱼致死低温的研究

在室内自然降温条件下，研究了三个品系尼罗罗非鱼（吉富品系，“７８”品系，“８８”品系）对低温的耐受力，计算得出每个品系的半致死低温，并对降温过程中尼罗罗非鱼行为活动的变化进行了观察。试验结果表明，在上海地区，当温度降低到１１℃时，罗非鱼开始死亡，到７．４℃时，全部死亡。吉富罗非鱼死亡温度范围是１１℃￣８．４℃，“７８”品系是９．８￣７．４℃，“８８”品系是１１℃￣７．４℃。对三个品系半致死低温的研     

Reproductive performance and the growth of pre-stunted and normal Nile tilapia (Oreochromis niloticus) broodfish at varying feeding rates

A 119-day experiment was conducted to investigate the effects of feeding rate and reproductive performance of stunted (S) and non-stunted or normal (N) Nile tilapia (Oreochromis niloticus). Both the groups were reared in tanks re-circulated with bio-filtered water and fed with floating pellets (30% crude protein) twice daily. Seed were harvested weekly from the mouths of incubating females. The study showed that early stunting with subsequent high feeding rate can improve both growth and reproductive output in female Nile tilapia. Broodfish type and feeding rate showed significant (P < 0.05) effects on both the frequency of spawning and the seed output. In general, seed output from normal broodfish increased linearly over the experimental period at all the feeding rates. However, seed output from stunted broodfish showed a linear increment for 3% feeding rate, exponential increment for 2% but quadratic for 1% showing decline after 10th week of the trial period. Results also showed that trends of seed output from stunted broodfish increased linearly with the increase in feeding rate showing that optimum rate could be higher than 3%. While from normal group the relationship was quadratic; increasing from 1%, peaked at 2% and declined at 3% feeding rate. Final GSI of the stunted females was significantly (P < 0.05) higher than that of normal females. The GSI of stunted fish showed a decreasing trend with the increased feeding rate. Both the broodstock groups fed at 1% biomass grew linearly whereas at 2 and 3%, they grew exponentially. As compared to the normal, stunted broodfish had significantly (P < 0.05) higher fat content in viscera although similar levels were in carcass and ovary. Carcass fat content was significantly (P < 0.05) lower in fish fed at 1% biomass but significantly (P < 0.05) higher in the ovary and viscera of fish fed at 3% biomass. This study shows that tilapia hatchery operators could manipulate the seed production according to the seasonal demand by using appropriate broodstock stunting and feeding strategies.     

两种不同地方种群尼罗罗非鱼遗传差异和分子遗传标记↑（*）

用ＡｐａⅠ，Ｂｃ１Ⅰ，Ｂｇ１Ⅱ，ＤｒａⅠ，ＥｃｏＲⅠ，ＥｃｏＲＶ，ＨｉｎｄⅢ，ＫｐｎⅠ，ＰｓｔⅠ，ＰｖｕⅡ，ＳａｃⅠ，ＸｂａⅠ，ＸｈｏⅠ等１３种限制性核酸内切酶对来自尼罗河上游和下游的两种不同地方种群尼罗罗非鱼的线粒体ＤＮＡ（ｍｔＤＮＡ）进行酶切分析，得到这两种罗非鱼的ｍｔＤＮＡ分子大小为：上游尼罗为１６９０９±９０ｂｐ，下游尼罗为１６９１２±１００ｂｐ。研究中还发现我国养殖的这两种不同地方种群尼罗罗非鱼，每一群体内个体间均存在ｍｔＤＮＡ酶切片段长度多态现象，而且群体间在ｍｔＤＮＡ水平上具有一定差异，依此构建了这两种不同地方种群尼罗罗非鱼ｍｔＤＮＡ限制性内切酶酶切图谱，建立了识别它们的分子遗传标记。     

新型饲料添加剂--发酵剂饲养罗非鱼的效果试验

用韩国引进的发酵剂（无味无色液体）作配合饲料的添加剂,进行饲养罗非鱼效果试验。结果表明添加发酵剂的两个试验组比对照组分别增重36．6％和48．1％,饲料系数比对照组降低28％和33％,同时发酵剂对控制水质和防治鱼病也有一定效果。     

Physiological and Biochemical Responses of Nile Tilapia (Oreochromis niloticus) Exposed to Aqueous Extracts of Neem (Azadirachta indica)

In this study, the physiological and biochemical response of Nile tilapia (Oreochromis niloticus) after 96 and 24 h exposure to aqueous extracts of neem (Azadirachta indica) in extract concentrations ranging from 0 to 32,000 mg/l was evaluated. After 96 h and 24 h exposure, the LC₅₀ of neem extract was estimated at 3,200 and 6,800 mg/l, respectively. Plasma cortisol increased beyond pre-treatment levels at neem extract concentrations above 2,000 mg/l over 96 h and above 4,000 mg/l over 24 h. Blood glucose increased at neem extract concentrations above 1,000 and 5,000 mg/l at 24 and 96 h, respectively. Neem extract concentration had little effect on serum sodium and plasma chloride. Hematocrit was higher than the control at neem extract concentrations above 1,000 mg/l in the 96 h exposure and above 2,000 mg/l in the 24 h exposure. Plasma ammonia increased significantly at neem extract concentrations above 2,000 mg/l for both the 96 h and 24 h tests. Immediately after beginning treatment, cortisol levels increased significantly at neem extract concentrations above 2,000 mg/l in the 96 h test and 4,000 mg/l in the 24 h toxicity test. Exposure to neem extract interfered with the antioxidant defense system of the fish by reducing liver catalase activity. Even though extracts of neem are less toxic at low concentration, concentrations exceeding 3,200 mg/l influence physiological and biochemical disturbances in fish.