粘稠性荚膜红假单胞菌对黄沙鳖稚鳖水质及生产性能的影响

探讨了荚膜红假单胞菌对黄沙鳖稚鳖水质及生产性能的影响.结果表明:使用荚膜红假单胞菌后,试验池与对照池相比较,水体中的溶氧量提高了31.17％,平缓pH值波动,显著降低水中氨氮含量,下降幅度达74.08％,加快了水中氨氮转化量,减少了氨氮的毒害作用.成活率提高了9.5％、重量增重了9.79 kg,其发病率比后者降低30....     

太空条件对荚膜红假单胞菌的生理指标及水质净化效果的影响

高活性水质净化的荚膜红假单胞菌的穿刺培养物和菌悬液搭载第18颗返回式卫星,并分别在培养基中添加诱变剂硫酸二乙酯。实验结果发现,搭载菌株的菌落形态发生变异,菌株的生长周期、生理学指标也发生了改变,通过对搭载荚膜红假单胞菌进行筛选获得2株水质净化能力较大幅度提高的优良突变菌株。通过性状稳定性研究,发现该菌株能较稳定地降低COD、氨氮值,提高溶解氧,从而达到净化水质效果。     

高活性光合细菌荚膜红假单胞菌培养特性初探

从洛河水中进行了光合细菌的分离,得到一株细胞活性高的荚膜红假单胞菌JM12,并对其培养条件进行了初步摸索。结果表明：该菌适宜在pH值6～7,盐浓度0％～3％,温度25℃～35℃以及有光照条件下生长。     

渔用荚膜红假单胞菌商品保存技术

为优化渔用荚膜红假单胞菌(Rhodopseudomona capsulata)商品保存技术,首先对实验室选育保存的高效荚膜红假单胞菌(菌种NC01)进行菌种扩大培养,再采用正交试验方法,研究不同的保存温度、菌液pH值、包装桶规格、透光度、颜色对渔用荚膜红假单胞菌商品保存期的影响,并采用单因素试验方法,研究在菌液中添加保护剂后的保存效果。结果显示,在商品菌液中添加0.5g/L维生素C,调节菌液pH值7.0,采用5L透光度2 500lx的绿色塑料桶包装,在温度25℃下保存效果最好。应用最适宜保存技术保存渔用荚膜红假单胞菌商品两个月,菌液的有效活菌数≥2.76×109个/mL,比普通保存技术提高了67.27%,两者差异显著(P0.05),为渔用荚膜红假单胞菌商品的保存提供了一种全新、有效的保存技术。     

球形红假单胞菌对三角帆蚌养殖水体水质的影响

将红螺菌科的红假单胞菌应用于三角帆蚌养殖水体,测定水化学环境因子变化情况。结果表明,光合细菌可稳定养殖水体pH,去除氨氮、亚硝酸盐氮、总氮,降低COD,促进水体氮循环,改善养殖水体水质。按水体体积计算,红假单胞菌密度109/mL的菌液合理施用量为0.1%。     

沼泽红假单胞菌对罗非鱼养殖水质及生长的影响

为探讨不同浓度的沼泽红假单胞菌(有效活菌数≥5×109个/mL)对罗非鱼养殖水质及生长的影响,采用单因子试验方法,试验共设4个处理,其中1#、2#、3#为试验组,依次在水体中投放3种不同浓度的沼泽红假单胞菌(4mg/L、6mg/L和8mg/L),每隔10d泼洒一次;4#为空白对照组。试验养殖180d,分6次测定水体pH值、溶氧量、化学需氧量(COD)和总无机氮(TIN)含量,试验结束起捕计算罗非鱼的产量、均末重、成活率以及饵料系数作为生产性能的评判指标。试验结果表明,试验组投放沼泽红假单胞菌能稳定水体pH值,提高溶氧量,有效抑制水体化学需氧量(COD)和总无机氮(TIN)等有毒物质的产生,试验组的平均单位产量、均末重和成活率均显著高于对照组4#(P<0.05),而饵料系数显著低于对照组4#(P<0.05)。多重比较来看,投放浓度为6mg/L组效果最好,单位面积产量最高。说明在水体中投放沼泽红假单胞菌,有效地改善养殖水体的水质状况,提高饵料转化率,促进鱼生长,增强抗病力,可在罗非鱼养殖区域大面积示范推广应用。     

蒙脱石对水相中沼泽红假单胞菌的吸附研究

通过测定吸附条件对吸附率及吸附菌量的影响,研究了蒙脱石对水相中沼泽红假单胞菌（Rhodopseudomonas palustris）的吸附特性。结果表明,当蒙脱石重量为0．5g时,吸附菌量和吸附百分率均达到较恒定的状态,且受到菌液起始浓度和体积的影响。不同pH条件下,蒙脱石对菌的吸附率随着pH值的升高而逐渐降低,当pH=9时,有效吸附率为72．67％。蒙脱石对菌的吸附率与离子强度成反比。不同温度条件下,蒙脱石对菌的吸附率呈现出先升高、后降低的趋势,温度30℃时吸附率最高,为86．55％。表明蒙脱石对水相中菌的吸附不仅依赖于生物体的化学属性和表面属性,也受到环境温度等条件的影响。     

红假单胞菌培养噬菌蛭弧菌的研究

为探索环保型的噬菌蛭弧菌宿主菌菌种,本文用红假单胞菌作为宿主菌进行了培养噬菌蛭弧菌的研究,系统地探索了pH值、缓冲系及温度等环境因子对培养效果的影响。实验表明用红假单胞菌培养噬菌蛭弧菌,其环境影响因子、出斑时间、出斑数量、培养收获浓度等方面均与大肠杆菌无差异,最佳培养条件为25℃～30℃、pH值7．0～8．0、PBS缓冲系、并添加一定量的钙、镁离子,光合细菌中红假单胞菌可完全取代污染菌大肠杆菌培养噬菌蛭弧菌,生产环保型的蛭弧菌制剂,并简化了生产程序。并建立了蛭弧菌的培养采收标准,同时初步提出了一种简易的蛭弧菌浓度的计算方法——裂解系数计算法。     

沼泽红假单胞菌对波吉卵囊藻常温保存效果的影响

波吉卵囊藻（Oocystis borgei）是亚热带对虾高位池养殖水体常见的优势种,对于稳定池塘生态结构,保持良好水体环境具有重要的意义.研究常温下波吉卵囊藻的保存效果有利于波吉卵囊藻的简易保存和虾类养殖的直接投入使用,以便推动水产养殖行业的微藻生态调控.在25℃、30℃和35℃下研究了不同沼泽红假单胞菌（Rhodopseudomonas palustris）浓度对波吉卵囊藻保存效果的影响.结果显示,在25℃、30℃和35℃下波吉卵囊藻保存的成活率、叶绿素a（Chl-a）质量浓度,以及恢复培养后的比增长率和ρ（Chl-a）与沼泽红假单胞菌添加浓度呈正相关,1.94×10^6个·mL-为最佳浓度;25℃为最适保存温度,但是在30℃下保存后恢复生长时发现比增长率要比25℃下保存的高（0.432）.因此,25℃下添加沼泽红假单胞菌浓度为1.94×10^6个·mL^-1时波吉卵囊藻的保存效果最佳,成活率达到87.5％,p（Chl-a）为31.14 μg·L^-1,经恢复培养后比增长率为0.424,p（Chl-a）为55.94 μg·L^-1.     

铜绿假单胞菌YY24对凡纳滨对虾生长及水质的影响

以凡纳滨对虾(Litopenaeus vannamei)为研究对象,探讨了水体中不同方式和不同浓度铜绿假单胞菌(Pseudomonas aeruginosa)YY24对凡纳滨对虾生长及水质的影响。试验设7个处理,每个处理3个重复,每个重复样本30尾,试验时间10 d,每2 d投放1次YY24,并保持其活性完好,有效养殖水体(50±3)L,控制温度(28±1)℃,盐度(20±1),每天每箱投料量按总重量的1%,溶解氧充足。试验期间,每24 h测定水体基础指标,在试验开始后的0、12、24、48、96、144、168、192、240 h测定水体理化指标。结果表明,与对照组相比,各试验组存活率与增重率均显著高于对照组(P0.05);各试验组均能明显净化水质,试验组的pH呈上升趋势,各试验组NH_4~+-N、NO_3~--N、NO_2~--N浓度均在96 h时就达到最低值;初始投放10~6CFU/m L浓度的YY24,在96 h内去除氨氮的效果较好,而每隔一天投10~4CFU/m L浓度YY24的持续作用效果更好。     

光合细菌FP04的筛选及对中华鳖养殖水质和生产效益的影响

从入海排污口污泥中筛选到一株有较强净化养殖水质能力的光合细菌,初步鉴定其为红螺菌,命名为FP04。实验室试验表明,FP04能有效降低养殖污水的CODcr含量。在中华鳖的养殖水体中加入不同浓度的FP04,结果与对照组比较,FP04可显著降低养殖水体中的氨氮和化学需氧量,并可减少甲鱼病害发生,提高甲鱼养殖成活率和增重率,其中以养殖水体中FP04浓度为9×104CFU/mL的效果最好,成活率和增重率分别提高14%和31%。     

Enhancing water use efficiency in monoculture of Litopenaeus vannamei: Impacts on pond water quality,waste production,water footprint and production performance

We studied the effect of rearing densities of Pacific white shrimp, Litopenaeus vannamei in three densities with three replicate treatments [T₁: 0.4 million post-larvae (PL) ha⁻¹, T₂: 0.5 million PL ha⁻¹, T₃: 0.6 million PL ha⁻¹] and water cutback approach on rearing environment, water use efficiency, water footprint and production performance. Conditional water exchange was carried out based on water quality parameters. Water quality suitability index was very good (7.5–9.0) up to 13th, 10th and 5th week of culture in T₁, T₂ and T₃, respectively; which was attributed to rearing density, smaller-sized shrimp and low early feed input. Optimum rearing density of 50 PL m^-2 (T₂) led to total water use of 3.25 × 10⁴ m³. It was seeming as a way to improve shrimp productivity (10.58 t ha⁻¹ 120 d⁻¹), consumptive water use index (1.72 m³ kg^-1 biomass), total water footprint (1229 m³ t⁻¹ biomass) and net consumptive water productivity (USD 1.28 m^-3). L. vannamei culture with low to moderate water exchange as in T₂, helped uphold water quality suitable for the shrimp growth, improved water use efficiency (0.58 kg biomass m^-3 water), minimized sediment load (45.3 m³ t^-1 biomass), effluent outputs (0.63 × 10⁴ m³), pumping cost (USD 30.1 t⁻¹ biomass produced), and ratio of output value to the cost of cultivation (1.97). The findings and advancement in knowledge would offer the basis to augment shrimp rearing efforts and the water management approaches will help in preventing the production of waste and effluent while increasing water use efficiency and production performance.     

Dietary medicinal herbs and enzyme treated fish meal improve stress resistances and growth performance at early juvenile stage of red sea bream Pagrus major

Red sea bream Pagrus major (RSB) weighing 0.09 g were fed on test diets, composed of 65% fish meal supplemented with 0.49% Crataegi fructus (Cf) and a mixture of Massa medicata, Cf, Artemisia capillaries and Cnidium officinale (HM) or a control diet without herbs, in trial 1. After air exposure and anaesthesia treatment, higher stress tolerances were obtained in herbal groups than control group. Moreover, after challenge test with Vibrio anguillarum, mortalities of the herbal groups were lower than the control group. There was no significant difference in growth performance among the treatments. Feed efficiency (FE) of the test groups was 124–141%. In trial 2, RSB weighing 0.11 g were fed on diets composed of 35% fish meal and 30% enzyme treated fish meal (EFM) with the same herbal treatments as trial 1. The herbal groups revealed higher final body weight and specific growth rate (SGR) and lower daily feed intake than those of the control group. The FE of test groups was 172–203%. These results indicate that the dietary herbs supplementation acts not only as recovery enhancer for some rearing stresses but also as growth enhancer, which is accelerated with dietary EFM in the early juvenile stage of red sea bream.     

养殖密度和温度对白斑狗鱼在设施养殖中生长的影响

研究了养殖密度和温度对白斑狗鱼稚鱼在设施养殖中生长的影响。经过30d的养殖试验发现养殖密度和温度对白斑狗鱼稚鱼在设施养殖中的摄食和生长都有显著影响。日增重、特定增长率、生长效率、摄食效率随密度的增大而减小,净增重24ind·m-3和16ind·m-3密度组最高;随着温度的升高,日增重、特定增长率、生长效率均呈现先升高后下降的趋势,其中24℃组生长最快,摄食效率则随温度的升高而增大。特定生长率与密度之间存在显著直线回归关系,其回归方程为SGR=7.30-0.122SD(r2=0.9927);养殖温度和特定增长率之间存在显著二次函数关系,其回归方程为SGR=-0.047T2 2.169T-19.56(r2=0.8342),当温度为23.1℃时,白斑狗鱼的特定增长率最大为5.544,表明白斑狗鱼最适生长水温应在23～24℃。白斑狗鱼尽管是凶猛性鱼类,但只要控制好一定的养殖密度和水温,进行设施养殖是可行的。     

Seasonal changes in sperm production and quality in the red porgy Pagrus pagrus (L.)

Cultured red porgy Pagrus pagrus (L.) males (n=6) were sampled every 2 weeks for milt, in order to monitor changes in sperm quality parameters during a whole spawning period. On 11 January 2001, 60% of the fish were spermiating, increasing to 100% in mid‐February and dropping to 30% by mid‐April. Sperm density showed a slight increasing trend, with mean values ranging between 8.6 and 23.7×10⁹ spermatozoa mL^?1. Sperm motility percentage exhibited a significant improvement during the spawning season (analysis of variance (anova ) P=0.0001). The duration of forward motility for the major part of the monitoring period ranged between 2 and 4 min. Red porgy spermatozoa maintained their viability for many days after whole storage of milt at 4°C. During the monitoring period there were significant changes in the mean duration of sperm survival after cold storage, ranging from 5 to 12 days. The total volume of expressible milt was maximal on 28 March, increasing from a mean value of 1.7 mL to 5.3 mL kg^?1. Milt production of captive‐reared red porgy does not appear to be limiting, when compared with the volume of expressible milt produced by other cultured marine fishes.     

Effects of water exchange protocols on water quality,sedimentation rate and production performance of Penaeus monodon in earthen ponds

This study was carried out in farmers' fields to quantify the total water and consumptive water use in grow‐out culture of Penaeus monodon under recommended package of practice with two different water management protocols: T₁, with no water exchange and T₂, with regulated water exchange. Treatment‐wise estimated total water use, was 2.09 and 2.43 ha‐m 122 day^?1, while the computed consumptive water use index (m³ kg^?1 biomass) was 5.35 and 6.02 in T₁ and T₂ respectively. Lower rates of water exchange (T₂) showed significantly improved (P < 0.05) crop performance in terms of performance index (19.75 ± 0.75), production‐size index (74.1 ± 3.4), survival rate (80.13 ± 1.7%) and productivity (2.44 ± 0.08 t) over the zero water exchange. The shrimp pond water quality suitability index (WQSI) infers that regulated water exchange (T₂) improved the overall suitability of water quality for shrimp culture. WQSI up to 90 days of culture ranged between 7.5–9.0 in T₂, needs little management while in the last month of rearing, it was good with moderate management requirements. Treatment‐wise sediment load ranged between 50.4–56.3 m³ t^?1 shrimp biomass. High intensity of water exchange and low apparent feed conversion ratio influenced in lowering the sedimentation rate. Regulated water exchange protocol (T₂) performed well (higher net total water productivity and net consumptive water productivity) against no water exchange (T₁). A higher OV:CC ratio (ratio of the output value to the cost of cultivation) indicated that T₂ had a distinct edge over the T₁ protocol.     

Effect of light limitation on the water quality,bacterial counts and performance of Litopenaeus vannamei postlarvae reared with biofloc at low salinity

The aim of this study was to evaluate the effect of light limitation on the water quality, bacterial counts and performance of Litopenaeus vannamei postlarvae reared with biofloc at low salinity (≈9 g L^?1). Two treatments were designed: T₁ = culture with natural sunlight and T₂ = culture in darkness. After 28 days, in both treatments, the final weight of shrimp was over 0.6 g with a specific growth rate over 7.4% d^?1, and a survival rate over 70%. In both treatments, Vibrio sp. concentration presented low values (culture with natural sunlight = 0.1 to 9.9 × 10² CFU mL^?1, culture in darkness = 0.4 to 11.7 × 10² CFU mL^?1) and Bacillus sp. had high values (culture with natural sunlight = 0.7 to 66.0 × 10⁴ CFU mL^?1, culture in darkness = 0.7 to 65.8 × 10⁴ CFU mL^?1). All water quality parameters remained within the ranges suitable for shrimp culture, except for alkalinity during the first stage of the study. Although in some sampling periods some significant differences were found in bacterial counts and water quality parameters, shrimp productive performance under culture with biofloc at low salinity was not affected significantly by light limitation.     

氢氧化镁对水质、底质改良的研究与应用

近年,沿海各地区水产养殖业发展迅速。由于内湾海区海水循环交换能力较弱,黑臭底泥的长期堆积,导致养殖水体水质和底质进一步恶化,然而这种问题普遍存在于封闭式或半封闭式水域环境中。对此,氢氧化镁作为水质、底质改良剂被应用于水环境的治理。本文概述了氢氧化镁的作用机理,包括氢氧化镁与悬浮颗粒物的静电、对氮磷的降解及对硫化氢的降解等作用;同时介绍了氢氧化镁在海水养殖场、淡水湖泊和水库、水华防控、赤潮防控及废水处理中的研究与应用;展望了氢氧化镁和纳米级氢氧化镁在水体环境领域的应用前景。     

不同杂交组合猪肥育性能与肉品质的研究

试验选用二元大长(Y×L)、三元杜长大(D×LY)、杜大长(D×YL)、三元皮大长(P×YL)4个杂交组合作为试验动物,进行生长发育性能、胴体品质性状测定,旨在为优质肉高效配套杂交组合筛选提供理论依据。研究表明:D×LY、D×YL日增重、料重肉比及屠宰率最优,日增重、屠宰率与L×Y差异显著(P<0.05),D×YL屠宰率、眼肌面积分别为76.2%、47.62cm2,为4组合中最高,并与Y×L差异显著(P<0.05),与D×LY、P×YL组差异不显著(P>0.05)。     

Sampling performance and operational quality of a frame trawl used to catch juvenile fish

SUMMARY: A sampling trawl with a rigid mouth; that is, the frame trawl, was designed so as to catch the large larval and juvenile fish more efficiently. The net consisted of four 13 m panels (nylon multifilament and twine diameter φ 0.75 mm, mesh size 8 mm). The frame of the net's mouth was composed of four stainless steel pipes (length 4 m, diameter φ 76 mm, thickness 5 mm). Several operations were conducted to investigate the capability of catching juveniles. A lot of Sardinops melanostictus juveniles, which are generally difficult to catch, were caught during every operation. Underwater observations proved that juveniles could not elude the capture. The frame trawl requires no special handling and is possible to operate in a rough sea.