益生菌在凡纳滨对虾育苗中的应用

实验研究了在凡纳滨对虾育苗中添加益生菌(芽孢杆菌、光合细菌或芽孢杆菌 光合细菌)对水体中pH值、H2S、COD、NH 4N、NO-2N和幼体成活率的影响。结果表明:光合细菌对提高水体的pH值有一定作用,而芽孢杆菌对pH值无显著影响;益生菌能显著降低水体中的H2S、NH 4N和NO-2N含量,其中光合细菌去除H2S和NO-2N的效果略优于芽孢杆菌,而芽孢杆菌去除NH 4N的能力比光合细菌强;实验中COD均在较适宜范围,益生菌对COD无显著影响。5mg·L-1芽孢杆菌和1mg·L-1芽孢杆菌 10mg·L-1光合细菌能显著提高育苗成活率。在实验中,1mg·L-1芽孢杆菌 10mg·L-1光合细菌的综合效果最佳,芽孢杆菌和光合细菌具有协同作用。     

稻蟹共作模式对池塘养殖尾水的净化效果研究

为探究稻蟹共作模式对池塘养殖尾水的净化能力,在宁夏银川地区的大规模稻蟹共作-池塘养殖耦合系统中,稻田种植面积52 hm²,水产养殖面积20 hm²,采取田间试验、水质分析相结合的方法,分别对稻田进水口、出水口水体中的溶解氧、磷酸盐、亚硝态氮、氨氮等水环境指标进行分析。结果表明,2020年试验稻田出水口氨氮、磷酸盐、亚硝态氮的最高去除率分别为69.2%、14.0%、100%,2021年试验稻田出水口氨氮、亚硝态氮的最高去除率分别为25.1%、100%,2022年试验稻田出水口氨氮、磷酸盐、亚硝态氮的最高去除率分别为76.9%、74.4%、100%。试验结果显示,2022年稻田对池塘养殖尾水的净化效果最好。由此表明,稻蟹共作模式可以显著降低池塘养殖尾水中的氨氮、磷酸盐、亚硝态氮水平,具有较好的水质净化效果,对生态环境产生积极影响。     

海马齿对海水养殖系统中氮、磷的移除效果研究

大量的外源性饵料和排泄物使海水养殖水体N、P以及有机物大量增加,导致水质恶化,是制约海水养殖业发展的主要因素。通过构建海马齿面积比为3∶2盐度为15的A、B 2组浮床海水养殖系统,以检验海马齿的N、P移除能力。结果显示,当海马齿处于生长启动期,A组和B组的水质指标与对照组之间无显著性差异(P>0.05);但当海马齿生长进入稳定期后,A组和B组的氨氮去除率为74%～91%和60%～91%,亚硝态氮去除率为93%～98%和71%～97%,总氮去除率为11%～25%和14%～33%,COD去除率为67%～85%和61%～81%,总磷去除率为41%～68%和35%～71%,试验组氨氮、亚硝态氮、COD和总磷浓度与对照组之间都存在显著性差异(P<0.05)。2组不同密度的海马齿浮床系统都显示了较高的N、P去除能力,表明海马齿在盐度5时能有效地吸收N、P,降低COD,减少有机物污染,改善养殖环境。     

3种有益微生物对菲牛蛭养殖水体理化因子及成活率的影响

为减少高密度养殖下菲牛蛭(Hirudinaria manillensis)疾病发生和养殖废水排放,研究比较了3种商品化有益微生物制剂(硝化细菌T1、光合细菌T2和EM复合菌T3)对养殖水体的净化效果。结果表明,3种有益微生物制剂在15d内均能使养殖水体的pH稳定在6.8以上,溶氧量(DO)分别比对照组提高30.12%、26.95%和46.12%;化学耗氧量(COD)分别比对照组低1.02mg/L、1.13mg/L和1.53mg/L;3个处理组对氨氮(NH4+-N)的平均降解率分别为48.48%、45.23%和63.10%,亚硝态氮(NO2-N)平均值分别比对照组低0.16mg/L、0.19mg/L和0.27mg/L;菲牛蛭存活率均高达90%以上,明显高于对照组的53%。3种有益微生物制剂均有显著增加溶氧量、降低氨氮、亚硝态氮和化学耗氧量的效应,对菲牛蛭养殖水体均具有很好的净化作用,其中以EM复合菌效果最佳。     

西沙永兴岛附近海域秋末氮磷营养盐加富对浮游植物生长限制的影响

为探讨西沙海域氮(N)和磷(P)对浮游植物生长限制的影响,2014年秋末在永兴岛附近海域S0站(111°59.843'E,17°30.364'N)进行了N、P营养盐的现场添加实验。添加氮的浓度依次为4μmol·L-1、8μmol·L-1、16μmol·L-1、32μmol·L-1,添加磷的浓度依次为0.25μmol·L-1、0.5μmol·L-1、1μmol·L-1、2μmol·L-1,添加氮和磷的浓度组合依次为4μmol·L-1+0.5μmol·L-1(N∶P=8∶1)、8μmol·L-1+2μmol·L-1(N∶P=4∶1)、16μmol·L-1+0.25μmol·L-1(N∶P=64∶1)、32μmol·L-1+1μmol·L-1(N∶P=32∶1)。结果显示:加富N+P后,叶绿素a浓度显著增长(P0.05),其中,32μmol·L-1NO-3-N+1μmol·L-1PO3-4-P添加组和4μmol·L-1NO-3-N+0.5μmol·L-1PO3-4-P添加组叶绿素质量浓度从初始的0.06 mg·m-3分别达到1.71 mg·m-3和1.10 mg·m-3,说明添加N/P范围在8~32之间可以促进浮游植物生长。在单独加富N和P后,叶绿素a浓度均无显著的增加(P0.05),说明单独添加N和P不能促进浮游物生长。限制因子分析表明,S0站点的浮游植物生长为N+P共同限制。     

福建省水口水库养殖库区氮的时空分布特征研究

为研究养殖库区水域氮的时空分布特征,于2014年3月至2015年2月在福建省水口水库范围内主要养殖库区选取15个采样点进行每月的监测和动态研究,全面分析了不同养殖库区、不同时期水体各形态氮的时空变化特征。结果表明,养殖库区水体总氮、氨氮、亚硝态氮平均浓度分别为1.38~2.15、0.24~0.53,0.03~0.06 mg/L。不同养殖库区水体各形态氮含量因季节更替而变化较大,总体趋势是总氮浓度冬季较高;除太平养殖库区外,其他养殖库区水体的氨氮浓度春季较高,浓度范围为0.466~0.596 mg/L;亚硝态氮浓度变化幅度不大,范围为0.009~0.031 mg/L。不同养殖区域水体中各态氮含量具有一定的相关性,雄江和太平养殖库区中总氮和氨态氮、亚硝态氮之间相关性不显著,黄田库区和湾口库区养殖区水体中总氮和氨态氮、亚硝态氮呈现负相关;尤溪口养殖库区水体中氨态氮和亚硝态氮呈显著负相关。     

3种有益微生物对菲牛蛭养殖水体理化因子及成活率的影响

为减少高密度养殖下菲牛蛭疾病发生和养殖废水排放,研究比较了3种商品化有益微生物制剂（硝化细菌T1、光合细菌T2和EM复合菌T3）对菲牛蛭高密度养殖水体的净化效果。结果表明,3种有益微生物制剂在15天内均能使养殖水体的pH稳定在6.8以上,溶氧量（DO）分别比对照组提高30.12％（T1）,26.95％（T2）和46.12％（T3）,化学耗氧量（COD）分别比对照组低1.02 mg/L（T1）、1.13 mg/L（T2）和1.53 mg/L（T3）;3个处理组对氨氮（NH4+ - N）的平均降解率分别为：48.48％（T1）,45.23％（T2）和63.10％（T3）,亚硝态氮（NO2- - N）平均值分别比对照组低：0.16 mg/L（T1）,0.19 mg/L（T2）和0.27 mg/L（T3）。3个处理组菲牛蛭存活率均高达90％以上,明显高于对照组（53％）。3种有益微生物制剂均有显著增加溶氧量、降低氨氮、亚硝态氮和化学耗氧量的效应。因此,本研究中3种有益微生物对菲牛蛭养殖水体均具有很好的净化作用,其中以EM复合菌效果最佳。     

绿狐尾藻对不同铵硝配比的生理响应

为了探究高氨养殖废水中一定比例的硝态氮对绿狐尾藻(Myriophyllum aquaticum)生长及生理特征的影响,采用营养液培养,在总氮浓度为15 mmol/L的条件下,以纯铵处理为对照(CK),设置NH+4∶NO-3=3∶1(以N3∶1表示)和NH+4∶NO-3=1∶1(以N1∶1表示)两个处理,研究绿狐尾藻对不同铵硝配比的生理响应。结果显示,培养至第21天,N1∶1处理的相对生物量和相对茎高分别为13.17 g和35.31 cm,显著低于N3∶1(19.59 g,41.78 cm)和CK组(17.82 g, 38.82 cm)(P<0.05)。不同处理下叶片中的氮含量为50.38~58.82 mg/g,显著高于茎中氮含量26.96~35.42 mg/g;但叶片中磷含量5.17~7.38 mg/g显著低于茎中的磷含量8.44~9.88 mg/g(P<0.05)。培养至第21天时,CK、N3∶1、N1∶1处理之间的叶片磷含量(6.76、7.06、7.38 mg/g)差异均达到显著水平(P<0.05),表现为N1∶1> N3∶1>CK。N1∶1和N3∶1处理叶片(7.03、6.75 mg/g)和茎中(6.43、5.04 mg/g)的可溶性糖含量均显著高于CK(3.58、3.27 mg/g)(P<0.05)。N1∶1处理叶片和茎中的叶绿素含量均显著高于CK和N3∶1处理(P<0.05)。研究表明,当处理中添加少量或不添加硝态氮时,有利于绿狐尾藻生长和生物量增加;当处理中硝态氮含量相对较高时,植株叶绿素和可溶性糖含量增加,同时吸收磷的能力增强。绿狐尾藻在不同铵硝配比的水体中均能保持良好的生长状态和较强的氮磷吸收能力,该结果为绿狐尾藻高效净化不同来源的养殖废水提供了理论依据。     

微生态制剂对沙塘鳢养殖水体净化效果

以沙塘鳢夏花培育水体为实验水体,应用光合细菌和芽孢杆菌的复合制剂作为养殖水体净化生物,探讨微生态制剂对沙塘鳢养殖水体的净化效果。实验设3个浓度组,分别为300、600、900mg/m3。每隔6d测定氨氮和亚硝态氮,7d测定总氮、总磷和COD。沙塘鳢经过60d养殖后,经测量后计算增重率和成活率。结果表明,微生态制剂能够有效去除养殖水体中的总氮,氨氮,提高沙塘鳢的增重率和成活率。     

添加营养物质提高商品水质净化菌剂净化能力的研究

利用室内试验,研究了添加营养物质提高商品水质净化菌剂SYMCORE BZTTM的净化能力的方法。研究分两部分,第1部分设1个对照组和2个试验组,研究了添加营养物质对水质净化菌剂的净化能力的影响;第2部分设1个对照组和15个试验组,研究了营养物质添加量配比与净化效果的关系。通过计算葡萄糖和磷酸盐的添加量对COD、NH4+-N和NO2--N去除率的影响,建立了相关模型。实验结果表明,添加葡萄糖和磷酸二氢钾能显著提高水质净化菌剂对养殖废水的净化能力。添加葡萄糖使COD、NH4+-N和NO2--N的去除率分别提高了21.92%、34.43%和57.41%;添加磷酸盐使COD、NH4+-N和NO2--N的去除率分别提高了30.02%、53.45%和15.08%。当C∶N∶P=62.5∶4.85∶1时,水质净化菌剂对养殖废水中COD的净化效果最佳;当C∶N∶P=37.5∶4.51∶1时,对氨氮的去除效果最好;当C∶N∶P=25∶2.97∶1时,对亚硝酸氮的净化能力最高。葡萄糖与磷酸盐的添加量与3种污染物去除率的关系可以用二项式曲线拟合。实验结果与拟合结果相符。为养殖废水的生物修复和微生物制剂的推广应用提供了理论和技术依据...     

Fish assemblage associations and thresholds with existing and projected oil and gas development

Energy development threatens fish and wildlife resources worldwide. This study used constrained ordinations to show fish assemblage structure associated with oil and gas well densities in the Colorado River Basin, Wyoming, but well densities explained only 6.4% of assemblage structure when compared to other factors. Threshold Indicator Taxonomic ANalysis showed significant negative threshold responses by some species to small levels of development (<0.15 wells km^?2), whereas positive thresholds were less distinct. Some native and imperilled species could be disproportionately affected if future oil and gas development proceeds in a manner that will impact aquatic resources. Although existing development has not substantially influenced regional fish assemblage structure, it appears to affect a subset of species. Understanding assemblage‐level responses to development can help land managers determine appropriate development levels, prioritise areas for monitoring associated with future development and identify where land protection measures may be needed to offset potential risks.     

Achieving sustainable aquaculture: Historical and current perspectives and future needs and challenges

Important operational changes that have gradually been assimilated and new approaches that are developing as part of the movement toward sustainable intensive aquaculture production systems are presented via historical, current, and future perspectives. Improved environmental and economic sustainability based on increased efficiency of production continues to be realized. As a result, aquaculture continues to reduce its carbon footprint through reduced greenhouse gas emissions. Reduced use of freshwater and land resources per unit of production, improved feed management practices as well as increased knowledge of nutrient requirements, effective feed ingredients and additives, domestication of species, and new farming practices are now being applied or evaluated. Successful expansion into culture of marine species, both off and on shore, offers the potential of substantial increases in sustainable intensive aquaculture production combined with integrative efforts to increase efficiency will principally contribute to satisfying the increasing global demand for protein and food security needs.     

Esophagoscopy and gastroscopy in dogs and cats. Technics and indications

A report is presented of esophagoscopy and gastroscopy in cats and dogs using flexible endoscopes. Following consideration of the basic equipment, an account is given of patient preparation and anesthesia, topography, investigation technique and normal findings. Diagnostic potential, indications and risks involved are discussed.     

Gar biology and culture: status and prospects

Many lepisosteid populations in North America have declined and many are now threatened as a consequence of habitat loss and alteration and commercial and sport overfishing. Over the last two decades, morphological, histological and molecular studies allowed distinguishing between different phases of development and the nutritional condition of larvae. Ontogeny of the digestive enzymes of gar larvae indicated the possibility to feed them artificial feeds since early developmental stages. An in vitro digestibility system to test different feed ingredients has been used. Important characteristics of artificial diets were identified through different feeding experiments. Endocrinological studies showed the feasibility of altering larval development and the digestive capacity of larvae. Cloning of gar growth hormone opened new avenues to enhance growth in the gars. Plasmatic vitellogenin was isolated and purified, to develop a competitive enzyme‐linked immunosorbent assay, which allowed the straightforward separation of males from females to establish appropriate proportions for reproduction and also was used to evaluate hormonal protocols to induce gonad recrudescence and spawning. This review analyzes the biology, ecology and physiology of different gar species as a basis for their domestication, mass production of larvae for repopulation experiments and for the culture of commercial‐size gar.     

奶牛酮病发病机理研究进展

结合国内外目前研究状况较为详细的综述了奶牛酮病的病因与发病机理,并分析了奶牛酮病发生的生化机制。旨在对临床实践中很好的认识诊断和群体监控奶牛酮病提供较为系统的理论依据,保证奶牛群的高产和稳产,从而创造良好的经济效益。     

添加植酸酶日粮不同磷水平和钙磷比对生长肥育猪血液生化指标和骨骼性能的影响

本试验利用饲养试验方法,研究玉米-豆粕型日粮中添加植酸酶时不同磷水平和钙磷比对生长肥育猪血清指标和骨骼性能的影响。试验选用162头20kg左右的杜长大三元杂交猪进行2×3(磷水平×钙磷比)因子饲养试验,试验分2个阶段进行,前期为生长期体重在20-60kg,后期为肥育期体重为为60-100kg。结果表明:添加植酸酶日粮磷水平对血清磷含量和碱性磷酸酶的活性影响显著(P<0.05);钙磷比对血清钙和血清磷含量的影响显著(P<0.05);添加植酸酶日粮磷水平和钙磷比对生长肥育猪骨骼性能的影响不显著(P>0.05)。在添加植酸酶条件下,降低日粮磷水平不影响猪的正常生长发育。     

加快城乡统筹，推进我国农垦体制创新与经济发展的研究与思考

“十一五”以来,我国农垦加快体制机制改革、结构调整和经济增长方式的转变的步伐,参与市场竞争,努力提升企业和产品竞争力,经济社会事业发展较快,对国家的贡献提升,职工收入、生活质量明显提高和改善,示范引领作用不断增强。本文针对农垦体制机制创新进展滞缓,战略定位与发展方向不明,经济增长方式转变和结构调整缺乏资本、人才、技术的支撑,没有处理好改革、发展、稳定、民生的关系,投资匮乏,发展后劲不足,人才短缺和劳动力素质低下的现状,提出在未来农垦体制机制创新中要特别关注改革方向、目标设定与评估,改革要在现行法律法规的框架内运作,改革时机的选择,处理好改革发展稳定与民生的关系,调整好内部利益分配关系,自觉融入区域经济,与地方协同发展等问题。为了促进农垦的发展,建议国家加大对农垦体制机制创新、现代农业建设、国有农场土地资源的保护、社会保障体系的完善等财政和政策的支持力度。     

川渝地区鸡皮刺螨的流行与综合防治

鸡皮刺螨是鸡的一种体外寄生的节肢动物,流行十分广泛,对养殖业发展有严重影响。为了解鸡皮刺螨的发病情况,对川渝两地的126个鸡场进行流行病学调查,感染率高达71%。同时,介绍了鸡皮刺螨的生活史、危害及防治措施,是防制鸡皮刺螨不可多得的资料。     

Composition and diversity of fish and fish catches in closures and open-access fisheries of Kenya

Abstract  Catch composition, relative abundance and diversity of fish catches in open access and three old fisheries closures were compared and contrasted with previous ecological studies. There was less variation in catch community composition among the fishing grounds than the closures, suggesting that fishing has homogenised catch composition. The trap survey found that some parrotfish [ Leptoscarus vaigiensis (Quoy &Gaimard), Calotomus carolinus (Valenciennes) and Scarus ghobban Forsskål] were relatively more common and that some important predators of macro-invertebrates [ Balistapus undulatus (Mungo Park) and Cheilinus chlorourus (Bloch)] were less common in the fishing grounds than closures. Unexpectedly, and in contrast to visual census results, cumulative number of species in catch surveys was higher in open access than closures sites. This may result from fishers covering more area and habitat or a reduction in the catch of competitively subordinate and rare species by aggressive, early-caught fish that can dominate bait. Comparisons of ecological visual census surveys and fisheries-dependent methods indicated that small differences in catch composition can reflect larger ecological differences and that baiting methods can underestimate biodiversity. Ecological impacts of fishing and large-scale changes in marine ecosystems must be considerable given the many fisheries-dependent assessments report modest changes.     

温度与盐度对老年低额蚤和蚤状蚤生长及生殖的影响_

温度与盐度对老年低额蚤和蚤状蚤生长及生殖的影响王丹丽，李明云，杨天勇，胡章（宁波大学，３１５０１０）关键词老年低额　，蚤状　，温度，盐度，生长，生殖ＥＦＦＥＣＴＳＯＦＴＥＭＰＥＲＡＴＵＲＥＡＮＤＳＡＬＩＮＩＴＹＯＮＧＲＯＷＴＨＡＮＤＲＥＰＲＯＤＵＣＴ...