Effect of using different types of organic animal manure on plankton abundance, and on growth and survival of Tilapia rendalli (Boulenger) in ponds

An experiment was conducted to evaluate the effect of using different types of organic manure on the plankton abundance, and growth and survival of Tilapia rendalli juveniles in ponds. Fish weighing 18.15±0.44 g were stocked into 12, 20 m² ponds at 2 fish m^?2 (40 fish pond^?1). There were three replicate ponds per treatment (chicken manure, cattle manure, pig manure, and no‐manure as a control). After 84 days the T. rendalli in the chicken manure treatment were significantly larger and had higher net annual yields than those in the cattle manure, pig manure and no‐manure treatments. The survival rates were not significantly different across the treatments. Significantly higher amounts of chlorophyll a and higher numbers of zooplankton were found in ponds fertilized with the chicken manure treatment. The overall results obtained in this study suggest that the use of chicken manure produces better results than cattle and pig manure treatments on unfertilized ponds.     

脆化专用饲料对罗非鱼生长和肌肉品质的影响

为考察脆化饲料对罗非鱼(Tilapia)生长和肌肉品质的影响,实验分别以配合饲料(对照组)、脆化饲料(试验组)喂养体质量为(115.30±23.69)g的罗非鱼99 d。结果显示:配合饲料组和脆化饲料组罗非鱼的增重率分别为185.25%、94.96%;饲料系数为1.87、2.94;肥满度为15.23、12.50;肌肉粗蛋白含量为19.40%、18.26%;粗脂肪含量为0.75%、1.32%;胶原蛋白为2.03、2.91;肌原纤维耐折力为33.93μm、64.84μm;滴水损失为2.59%、1.82%。与对照组相比,在生长方面,脆化饲料组罗非鱼增重率、肥满度显著降低,饲料系数显著增加(P<0.05);在肌肉品质方面,肌肉的粗蛋白含量和滴水损失显著降低,而粗脂肪含量、胶原蛋白含量和肌原纤维耐折力显著提高(P<0.05)。结果表明,脆化饲料在一定程度上改善了罗非鱼的肌肉品质。     

罗非鱼碎肉酶法制备蛋白胨的工艺研究

为探讨罗非鱼碎鱼肉酶法制备蛋白胨的加工工艺,采用正交试验的方法,分别研究了木瓜蛋白酶、AS.1398中性蛋白酶、复合蛋白酶水解罗非鱼碎肉制备蛋白胨的工艺条件。结果表明:木瓜蛋白酶的最佳水解工艺条件为pH6.5,温度65℃,水解时间4h,加酶量1250 U/g,蛋白胨得率达12.63%;AS.1398中性蛋白酶最佳水解工艺条件为pH 7.5,温度55℃,水解时间4 h,加酶量750 U/g,蛋白胨得率达13.25%;复合蛋白酶的最佳水解工艺条件为pH 7.0,温度50℃,水解时间4.5 h,加酶量850 U/g,蛋白胨得率达11.43%。     

Physical and chemical characteristics of sediments in catfish, freshwater prawn and carp ponds in Thailand

Sediment samples were collected from 42 catfish (Clarias hybrid) ponds, 40 freshwater prawn (Macrobrachium rosenbergii) ponds and 18 carp (Puntius spp.) ponds in Thailand. Regression analysis revealed that pond age (1–30 years) was not a major factor influencing the physical and chemical composition of pond sediments. Sediment depth, F+S horizon thickness and bulk density of S horizon were greater (P<0.05) in carp ponds than in catfish and prawn ponds. This occurred because sediment was removed from catfish and prawn ponds more frequently than from carp ponds. Total carbon, organic carbon and total nitrogen concentrations were greater (P<0.05) in carp ponds than prawn and catfish ponds. Few ponds had sediment organic carbon concentrations above 3%, and carbon:nitrogen ratio values did not differ (P>0.05) among ponds for the three species. Total phosphorus and other sediment phosphorus fractions increased in the order prawn ponds, carp ponds and catfish ponds. Sediment sulphur concentrations also increased in the same order. There were no differences in major or minor nutrient concentrations in sediment that would influence aquacultural production. Although there were significant correlations (P<0.05) between various sediment quality variables, no single variable or group of variables would be useful in estimating sediment quality. Pond bottom management practices used by producers in Thailand included drying of pond bottoms between crops, liming, tilling and periodic sediment removal. These practices have maintained relatively good bottom quality. They should be continued in Thailand and adopted in other places.     

罗非鱼声控投饵方法

鱼类的摄食活力可以用摄食过程发出的声音直接测量。本研究通过构建声学监测平台,应用带宽1 Hz-470 kHz,在40 kHz以下自由场电压灵敏度级-217 dB(基准值为1 V/μPa)的水声检测设备,采集罗非鱼摄食过程中产生的声信号,分析其摄食活力。研究表明,罗非鱼摄食时发出的声音在0-6 kHz可区分于背景噪声,其声功率与摄食活力呈正相关。声功率移动平均值反应鱼摄食活力趋势,可作为食欲反馈,结合生长模型和投喂模型可以组成投饵策略。     

Quality of liming materials used in aquaculture in Thailand

Samples of 45 brands of liming materials were obtained in Thailand and analyzed for chemical and physical properties. Eight of 10 products sold as ground calcium carbonate (calcitic agricultural limestone) were properly identified by vendors and of high quality, that is, neutralizing value and fineness rating above 85%. Seven of 15 products sold as ground dolomite (dolomitic agricultural limestone) were properly identified, seven were ordinary pulverized limestone instead of dolomite, and one was lime. The seven dolomitic agricultural limestone samples were of high quality, that is, fineness ratings above 85% and neutralizing values above 95%. Only two of eight misidentified samples were of high quality. Only one of four products sold as marl had neutralizing value and efficiency rating above 85%, but all were properly identified. Five products sold as crushed seashell had been burned and should have been identified as lime. However, neutralizing values (72–103%) were lower than those of good quality lime. All 13 samples sold as lime were properly identified, and eight were of good quality, that is, neutralizing value above 120% and fineness rating above 85%. The cost of liming materials ranged from US$ 0.01 to 0.20kg^–1 for marl and from US$ 0.10 to 0.14kg^–1 for lime. There was no relationship between product quality and cost. Fish and shrimp farmers in Thailand should insist that manufacturers and vendors of liming materials provide data on product composition.     

罗非鱼内脏中酶的筛选

以罗非鱼内脏为原料,经过酶的提取、活性测定及酶含量计算, 对罗非鱼内脏中的蛋白酶、凝乳酶、脲酶、超氧化物歧化酶、胆碱酯酶、乙酰胆碱酯酶和酸（碱）性磷酸酶进行比较和评价。结果表明：蛋白酶、超氧化物歧化酶、胆碱酯酶和碱性磷酸酶在罗非鱼内脏中含量多、活性高,具有进一步提取研究价值。     

以色列红罗非鱼与其他罗非鱼群体杂交子一代在海水中生长性能分析

利用以色列红罗非鱼品系(Israel strain of red tilapia,R)、吉富品系(GIFT strain of Nile tilapia,J)(Oreochromis niloticus)、奥利亚罗非鱼(Blue tilapia,A)(O.aureus)、尼罗罗非鱼(Nile tilapia,N)(O.niloticus)等群体,构建了具有广泛遗传变异罗非鱼育种基础群体。采用人工定向交尾技术,获得了15个以色列红罗非鱼群体内和65个以色列红罗非鱼群体及其他群体间杂交全同胞家系。待家系平均体重5-8 g时进行标记,每个家系随机取样40尾标记个体放入养殖池中,采用逐渐提高盐度驯化至养殖盐度为28,养殖150 d后进行生长性能测试以及杂交和体重生长遗传参数分析。结果显示,在研究的所有群体内和群体间的交配组合中,以色列红罗非鱼品系(♀)与尼罗罗非鱼(♂)杂交的杂交组合(R×N)子一代生长速度最快,优于其他杂交组合,其平均体长、平均体重和绝对增重率分别为24.44 cm、385.23 g和4.94 g/d;ANOVA和LSD多重比较分析结果显示,杂交组合间在体长、体重指标上均达到差异极显著(P<0.01),R×N与除J×R杂交组合外的其他3个杂交和1个群体自繁组子一代两两间存在显著差异(P<0.05)。利用实验构建的80个家系共2496个个体体重数据,考虑家系标记时的平均体重、池塘、雌、雄等因子,建立了遗传参数分析模型,估计体重的遗传力为0.46±0.07,属于中等遗传力。因此,利用本研究收集的罗非鱼基础群体,开展罗非鱼在海水中生长性状选育,具有很大的遗传改良潜力。     

罗非鱼内脏中酶的筛选

以罗非鱼内脏为原料,经过酶的提取、活性测定及酶含量计算,对罗非鱼内脏中的蛋白酶、凝乳酶、脲酶、超氧化物歧化酶、胆碱酯酶、乙酰胆碱酯酶和酸(碱)性磷酸酶进行比较和评价。结果表明:蛋白酶、超氧化物歧化酶、胆碱酯酶和碱性磷酸酶在罗非鱼内脏中含量多、活性高,具有进一步提取研究价值。     

Effect of organic matter concentration on agricultural limestone dissolution in laboratory soil–water systems

Laboratory soil – water systems in which soil organic matter was increased by 0.0%, 0.5%, 1.0%, 2.0% and 4.0% by adding dry, chopped ryegrass (Lolium perenne) shoots to sandy soil containing 0.06% organic matter. Agricultural limestone was added to the systems, and pH, alkalinity and hardness of the water were monitored for 65 days. The pH, alkalinity and hardness increased with greater soil organic matter concentration. Amounts of carbon dioxide released by microbial respiration increased at the higher soil organic matter concentrations, and this resulted in more rapid and greater solubility of agricultural limestone. The results suggest that greater soil organic matter concentrations in ponds favour the rate and extent of agricultural limestone dissolution.     

美国罗非鱼贸易现状及展望

利用近年美国罗非鱼市场信息数据,对美国罗非鱼主要进口国家、进口总量变化、产品种类变化、价格变化等问题进行深入的分析,提出未来罗非鱼市场展望及建议,旨在为中国罗非鱼产业发展提供参考。数据分析表明,中国内地和中国台湾占据美国罗非鱼进口贸易近80%的市场份额,其中以冻全鱼和冻鱼片为主,这2种产品在美国市场将继续处于稳定增长的态势。价格分析结果说明,冻鱼片价格明显高于冻全鱼,但中国内地由于产品质量和品牌问题,产品价格普遍低于同类产品市场平均价,表明中国内地必须进一步加强对罗非鱼产品的质量管理,才能获取更大的利润和市场份额。     

罗非鱼迟缓爱德华氏菌病的分离鉴定

从广西某鱼场的发病罗非鱼(Tilapia nilotica)中分离到1株呈β溶血的革兰氏阴性杆菌,在普通琼脂平板上生长,菌落圆形,边缘整齐,灰白色,湿润菌落,直径为0.5～1.0 mm,有动力,接触酶阳性,赖氨酸及鸟氨酸脱梭酶阳性,还原硝酸盐为亚硝酸盐,发酵葡萄糖、蔗糖、麦芽糖,经细菌形态、培养特征、生化特性测定结果均符合迟缓爱德华氏菌的特征.应用PCR技术扩增出576 bp目的片段,通过PCR产物核苷酸序列测序及Blast比对结果,进一步确定为迟缓爱德华氏菌.致病性试验结果显示分离菌株具有致病性,对氧氟沙星、氯霉素、氟哌酸、恩诺沙星、先锋霉素等高度敏感.     

罗非鱼暴发性流行病组织病理的研究

本文报告了由链球菌引起的罗非鱼暴发性流行病组织病理学研究.主要组织病理变化:鳃充血,鳃上皮增生、融合,结构崩解;心肌纤维变性,肌间白细胞浸润;肝脏颗粒变性和脂肪变性;肠道粘膜上皮变性、坏死、脱落、固有膜炎性白细胞浸润;肾脏受损严重,白细胞浸润,肾小管上皮细胞坏死、解体,小动脉血管壁玻璃样变性;眼睛脉络膜和眶骨膜组织炎性坏死,晶状体纤维断裂和脱离.     

雄性化罗非鱼精养高产试验

１９９４年进行了主养雄性化罗非鱼高产试验，经过１０９天养成，每亩产鱼１１８０ｋｇ。其中罗非鱼１０３０ｋｆ，产值１２３００元，纯利４３００元。专家鉴定认为，实际产量，技术水平达到山东省先进水平。     

Effect of Using Low-Protein Diets in Semi-Intensive Pond Cage Culture of Tilapia,Tilapia rendalli (Boulenger)

ABSTRACT

An experiment was carried out to determine the effect of using low-protein diets on production of Tilapia rendalli in semi-intensive pond cage culture. This was carried out at Bunda College of Agriculture's fish farm, University of Malawi, where two 200-m² earthen ponds of 1-m depth were used for two months from February 2003 to early April 2003. Each pond had 6 cages of 1 m³ in size stocked with 15 fish, each 4.8 ± 1.2 g average weight and 6.7 ± 0.6 cm average length. Chicken manure was used as the organic manure applied at 500 kg/ha/wk and also acted as a control. All treatments were replicated three times. It was observed that fish growth was higher in the soybean meal-based diet, with final weight of 34.4 g, followed by sunflower cake, with final weight of 23.3 g. The lowest was 14.4 g in the chicken manure only, and cottonseed-based diet had final weight of 19.5 g. These results also agree with the specific growth rate (SGR) that ranged from 2.1%/day in the cages only fertilized with chicken manure to 3.6%/day in the soybean-based dietary treatment. The lowest feed conversion ratio of 1.2 was also observed in the soybean-based dietary treatment. This suggests that the use of lower protein diets that contain soybean would produce better results and may increase yield when combined with fertilization, as evidenced by high fish survival rates of more than 93% in all treatments.     

积温和放养规格对网箱养殖罗非鱼的影响

利用大秋房水库网箱养罗罗非鱼的６年生产记录，以放养规格以及每天大于１５℃、大于２０℃的积温和天数作为自变量、以个体增肉倍数、饵料系数作为变量，进行一元和二无回归分析。结果发现：每天大于１５℃的积温和天数与增肉倍数相关最显著；第天大于１５℃的天数和放养规格与饵料系数相关也较显著。     

Physical and chemical characteristics of soil from tiger shrimp aquaculture ponds at Malacca,Malaysia

Soil physicochemical properties of the growout ponds of black tiger shrimp (Penaeus monodon) were examined in relation to shrimp yields for one production cycle. The culture ponds were old (>5 years) and new (newly constructed) types. Soil texture was silty clay with low sand content and high proportion of clay for both the pond types with alkaline soil pH (7.87–9.71). Organic matter (OM) concentration was higher (7.48 ± 0.01%) in old ponds and positively related (r = 0.58, P < 0.05) with total nitrogen (TN). The major cations (Ca, Mg, and Na) were higher in the soil of old ponds and did not fluctuate significantly during culture. The majority of trace elements, i.e., Fe (349.22 ± 35.7 ppm), Mn (56.19 ± 30.2 ppm), Zn (88.56 ± 8.09 ppm), Al (454.3 ± 200.6), Pb (1.3 ± 0.96 ppm), Co (3.4 ± 0.2), V (6.56 ± 1.79 ppm), Cr (19.32 ± 0.63 ppm), Ti (82.78 ± 54.3 ppm), As (5.60 ± 0.28 ppm), Ag (0.38 ± 0.5 ppm), and Sb (3.89 ± 0.48 ppm) were found to be higher in new pond soils than the old ponds. Except for soil manganese, no major fluctuations in trace elements were observed during the culture period. Shrimp growth was not significantly different in the two types of ponds, and no distinct correlation between shrimp growth and element content of soils could be drawn. The results indicate that shrimp pond age may not affect production of shrimp if soils are properly managed pre- and postculture. The differences in production in different ponds might be the result of management practice such as quality of shrimp post larvae, pond preparation, water and feed quality, and available live feed in the pond bottom or other environmental factors like water nutrients and physicochemical parameters.     

不同罗非鱼品系感染无乳链球菌后对血液和肝胰腺生化指标的影响

为探究无乳链球菌(Streptococcus agalactiae)感染后对罗非鱼的血液和肝胰腺生化指标的影响,本研究以吉富罗非鱼(Oreochromis niloticus)抗病选育系F5代、奥尼罗非鱼(Oreochromis aureus × O. niloticus)、吉富罗非鱼“百桂”品系为对象,通过人工腹腔注射感染无乳链球菌,检测感染后不同时期肝胰腺和血液中的酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、总抗氧化能力(T-AOC)和溶菌酶(LZM)活性的变化。结果显示,奥尼罗非鱼、吉富罗非鱼抗病选育系F5代和吉富罗非鱼“百桂”品系的平均死亡率分别为55.4%、60.5%和78.6%,表明奥尼罗非鱼抗感染能力最强;3个品系感染无乳链球菌后,肝胰腺组织中的ACP、AKP、SOD和T-AOC酶活力均呈先升高后下降的趋势,其中,在感染后24 h,奥尼罗非鱼的AKP和CAT酶活力显著高于吉富罗非鱼抗病选育系F5代和吉富罗非鱼“百桂”品系;而感染后24 h,血清中ACP、AKP、LZM、CAT和T-AOC酶均显著升高,而SOD酶则下降,其中,奥尼罗非鱼的ACP、AKP、CAT和T-AOC酶活性明显高于吉富罗非鱼抗病选育系F5代和吉富罗非鱼”百桂”品系。综合比较6种酶在感染后不同时期的活性变化及3个品系的感染存活率,筛选出AKP和CAT作为评估罗非鱼抗无乳链球菌感染能力强弱的指标。