对虾养殖池副溶血弧菌的分离鉴定及其耐药特征、毒力基因分析

为了解对虾养殖池中副溶血弧菌(Vibrio parahaemolyticus)的耐药性和毒力基因的携带情况，2018年从山东4个地区的对虾养殖池收集分离副溶血弧菌，采用Kirby-Bauer纸片法检测其对12种抗生素的耐药性，用PCR方法检测其携带耐热直接溶血素基因(tdh)和耐热相关溶血素基因(trh)的情况。从对虾养殖池共分离副溶血弧菌50株。药敏实验结果显示，副溶血弧菌对庆大霉素、硫酸新霉素和氨苄西林的耐药情况最为严重，耐药率分别高达98%、90%和86%，对氟苯尼考、氯霉素、头孢他啶等敏感性较高，耐药率分别为10%、10%和20%。88%的菌株具有多重耐药性。毒力基因检测结果显示，所有菌株均不携带tdh基因，4%的菌株表现为trh阳性。本研究表明，对虾养殖水环境中的副溶血弧菌对抗生素的耐药性较为严重，应加强副溶血弧菌的病原学监测，在养殖过程中合理使用抗生素，以实现水产养殖业健康发展。     

十足目虹彩病毒(DIV1)环介导等温扩增(LAMP)检测方法的建立及应用

本研究以十足目虹彩病毒(Decapod iridescent virus 1, DIV1)主要衣壳蛋白基因为靶序列设计引物，建立了DIV1的环介导等温扩增(Loop-mediated isothermal amplification, LAMP)检测方法，并以pMD18-DIV1质粒标准品为模板对该方法的检测灵敏度、检测特异性等进行了评估。结果显示，此方法最适反应温度为64.4℃，优化后的25 μl反应体系中包含2.5 μl 10×Isothermal amplification buffer、4.0 mmol/L Mg2+、1.2 mmol/L dNTPs、6.4 U Bst 2.0 WarmStart® DNA聚合酶、0.8 μmol/L EvaGreen®和4.4 μl ddH2O。该方法检测灵敏度下限为3.54×102拷贝/反应；与虾肝肠胞虫(EHP)、致急性肝胰腺坏死病副溶血弧菌(VpAHPND)、对虾偷死野田村病毒(CMNV)、传染性皮下及造血组织坏死病病毒(IHHNV)、白斑综合征病毒(WSSV)、桃拉综合征病毒(TSV)和黄头病毒(YHV)等主要虾类病原没有交叉反应；具有较好的重复性和稳定性。以GeneFinder®替换EvaGreen®并将其预置于反应管内，结合上述扩增方法可实现对DIV1的现场快速高灵敏检测。本研究建立的DIV1-LAMP实时荧光定量和现场检测方法具有灵敏、特异和快速等特点，为近几年新发虾类病原DIV1的定性、定量以及现场快速检测提供了新的技术选择，有利于对虾养殖业中开展DIV1的监测、预警和防控。     

The effects of artificial substrate and stocking density on Pacific white shrimp (Litopenaeus vannamei) performance and water quality dynamics in high tunnel-based biofloc systems

The use of artificial substrates in shrimp aquaculture may allow for production of shrimp at increased densities while providing a growth medium for microbes that assist with water quality processes and provide supplemental nutrition for shrimp. Greenhouse-based shrimp production systems can extend the shrimp production season in temperate climates while conserving water and energy. For this study, we evaluated the effects of providing extra substrate and shrimp density on water quality and shrimp production in greenhouse-based biofloc systems. Four 11-m³, wood framed, and rubber-lined tanks were constructed in each of four high tunnel greenhouses (for a total of 16 tanks). Four treatments were evaluated: high-density stocking with substrate (HDS), high-density stocking with no substrate (HDNS), low-density stocking with substrate (LDS), and low-density stocking with no substrate (LDNS). Each treatment was randomly assigned to one tank in each tunnel to block for location. No artificial heat was used, and shrimp were grown for 120 days. High-density systems were stocked at 200 shrimp/m³ while low-density tanks had 100 shrimp/m³. Adding substrate increased total in-tank surface area by 13.4%. The addition of substrate had no significant effect on any shrimp production or standard water quality parameters. Shrimp had significantly greater final weight, faster growth rate, and lower feed conversion rate in low-density treatments (P ≤ 0.02 for all). Total shrimp biomass production was significantly higher in high-density treatments (HD: 4.0 kg/m³; LD: 2.3 kg/m³; P < 0.05). There were no significant differences in survival between densities (HD: 91.3%; LD: 94.5%; P = 0.43). Peak and overall mean nitrite levels were significantly higher in high-density treatments compared to low-density treatments. Dissolved oxygen levels and pH over the course of the study were significantly lower in high-density treatments, likely due to increased respiration rates in the water column. This project shows the feasibility of shrimp production in temperate climates with no artificial heat using high tunnel greenhouses, few impacts of added substrate on shrimp production, and increased shrimp density can result in much larger harvests with few negative impacts on production metrics.     

Monitoring shrimp growth with control charts in aquaculture

This work proposes a method for the statistical monitoring of the weekly weight of shrimp in a fish farm. The design of control charts for shrimp growth presents several challenges, the main ones being the presence of trend and autocorrelation. Several control charts are proposed, the most efficient being a chart based on the residuals of a second order autoregression whose parameters vary with the week. A control chart with less computational complexity is also provided. It is simply based on growth rates and works well at detecting negative weight changes. Real data from a large shrimp farm has been used for both the design and the evaluation.     

柘林湾沿岸对虾养殖环境的氮磷负荷与区域分布

研究了柘林湾沿岸对虾养殖产生的环境氮磷负荷及其来源的数量和比例。2006年柘林湾沿岸对虾养殖产生的环境氮负荷为210.21t,其中来源于对虾的排泄氮、粪氮和残饵氮分别为157.10t、39.61t和13.50t;环境磷负荷为45.45t,其中排泄磷、粪磷和残饵磷分别为4.93t、24.87t和15.65t。对虾养殖环境氮负荷主要来源于对虾的排泄,占氮负荷的74.74%,而磷负荷主要源自粪便,占磷负荷的54.72%。柘林湾沿岸对虾养殖的环境氮磷负荷量以湾北部沿岸最大,北部、西部和东部沿岸环境氮负荷分别为144.86t、53.99t和11.36t,环境磷负荷分别为31.32t、11.68t和2.46t。     

虾片饲料双滚筒干燥生产工艺及初步配方筛选的研究

该研究首次尝试利用双滚筒干燥技术来生产虾片饲料，考察了不同工艺参数及配方对虾片饲料性能的影响。研究中以成膜率和悬浮性为评价指标，采用正交试验设计考察蒸汽压力、滚筒转速和浆液浓度三个工艺参数对产品的成膜率和悬浮率的影响，优选出最佳工艺参数。同时，对比研究了虾片饲料生产过程中901、面粉、褐藻胶、蛋清粉4种成膜剂的成膜性能，并最终确定其最适的添加量。结果表明最佳工艺参数为蒸汽压力0.4MPa、浆液浓度30%、滚筒转速1000r／min； 901是最佳成膜材料，其最适添加量为7%。     

Lethal Effects of Elevated pH and Ammonia on Early Life Stages of Hybrid Striped Bass

Hybrid striped bass larvae (striped bass, Morone saxatilis, ♀ x white bass, M. chrysops, ♂) are often stocked into fertile culture ponds. High rates of photosynthesis may result in elevated pH which can be lethal to fry and can affect the toxicity of ammonia. Six-hour static toxicity tests were performed on hybrid larvae of various ages to determine the toxicity of elevated pH and the effects of elevated pH on ammonia toxicity. Six-hour mortality threshold pH's with no measurable ammonia were estimated for various age larvae and found to be between pH's 9.8 and 10.2 for D2 (Dl is day of hatch), between 9.0 and 9.4 for D4, between 8.8 and 9.2 for D13, and between 9.2 and 9.4 for D20 fish. The addition of 0.7% NaCl had no effect on the toxicity of elevated pH to D2 or D4 fish but caused a significant reduction in the mortality of Dl3 and D20 fish exposed to high pH. The tolerance to elevated pH decreased as ammonia concentration increased. Sub-lethal un-ionized ammonia concentrations increased the toxicity of elevated pH, suggesting an interaction of pH and un-ionized ammonia toxicity.     

水文气象因子变化对自然海区对虾早期生命的影响

利用渤海湾对虾卵子、幼体和幼虾调查资料，引用相对成活倍数的概念，并选择与对虾早期生命有因果关系的水文气象因子，通过相关分析方法分析讨论了水文气象因子变化对对虾早期生命的影响。结果表明，６￣７月盐差、５月中旬产卵场现场水温和黄河径流对对虾早期生命影响较明显。     

对虾养殖生态环境的研究现状和展望

依据近几年的有关参考文献对有关对虾生态环境的研究成果及存在的问题进行了评述。从生态学方面阐述了对虾养殖生态系统的特点，提出对虾养殖生态环境中理化因子的研究应该更注意与生物及微生物因子的结合。     

对虾病毒病的研究现状

主要依据９０年代关于对虾病毒病的资料，就对虾病毒的病原、诊断技术、预防进行综合述评，总结概括了对虾病毒病的研究现状。