稻田和池塘养殖禾花鲤肌肉营养与品质分析

为评估不同养殖环境对禾花鲤(Cyprinus carpio)肌肉营养与品质的影响,采用国标法检测稻田和池塘2种养殖环境下禾花鲤肌肉常规营养成分、质构特性、氨基酸和脂肪酸组成。结果显示,池塘组禾花鲤肌肉粗蛋白和粗脂肪含量显著高于稻田组(P<0.05),水分含量显著低于稻田组(P<0.05),灰分含量2组差异不显著(P>0.05);池塘组肌肉粘性显著高于稻田组(P<0.05),内聚性和剪切力显著低于稻田组(P<0.05),其他质构指标2组间差异不显著(P>0.05);肌肉氨基酸测定结果显示,池塘组氨基酸总量(?TAA)、鲜味氨基酸(DAA)、必需氨基酸(EAA)、非必需氨基酸(NEAA)显著高于稻田组(P<0.05),?EAA/TAA和?EAA/NEAA显著低于稻田组(P<0.05),2组禾花鲤必需氨基酸构成比例均符合FAO/WHO标准;在鲜味氨基酸含量方面,池塘组主要的4种呈味氨基酸含量均显著高于稻田组(P<0.05)。根据氨基酸评分(AAS)和化学评分(CS)标准,2组禾花鲤肌肉第一、二限制性氨基酸均分别为色氨酸(Trp)和缬氨酸(Val);在脂肪酸测定结果中显示,池塘组单不饱和脂肪酸(∑MUFA)含量显著高于稻田组(P<0.05),但多不饱和脂肪酸(∑PUFA)、EPA+DHA和∑n-3PUFA/ ∑n-6PUFA显著低于稻田组(P<0.05)。综上所述,池塘和稻田养殖条件下,禾花鲤均为优质的蛋白质来源,但不同养殖环境对禾花鲤肌肉营养与品质有显著影响。从常规营养成分、氨基酸评分方面看,池塘养殖条件下禾花鲤肌肉营养价值更高;从脂肪酸角度来看,稻田养殖禾花鲤肌肉具有较高的EPA+DHA含量以及n-3/n-6多不饱和脂肪酸比例,更适合高血脂和心血管疾病等患者食用,从质构性来看,稻田养殖环境下禾花鲤肌肉更具嚼劲。     

察尔森水库细鳞斜颌鲴营养成分分析及评价

本试验对察尔森水库细鳞斜颌鲴(Plagiognathops microlepis)肌肉营养成分进行了分析及评价。试验采用常规营养成分分析法对细鳞斜颌鲴肌肉一般营养成分、氨基酸组成、脂肪酸组成进行了测定。结果表明:细鳞斜颌鲴肌肉中水分含量为79.31%、粗蛋白含量为16.56%、粗脂肪含量为0.94%、灰分含量为1.13%、总糖含量为0.38%。细鳞斜颌鲴肌肉共检出18种氨基酸,其中必需氨基酸(EAA)8种,非必需氨基酸(NEAA)10种,总氨基酸(TAA)含量为16.28%,EAA含量为6.72%,NEAA含量为9.56%;EAA/TAA(41.29%)及EAA/NEAA(70.32%)均在FAO/WHO推荐值以上。氨基酸评分(AAS)和化学评分(CS)结果是第一限制性氨基酸均为色氨酸(Trp),而第二限制性氨基酸,AAS是苏氨酸(Thr),CS是苯丙氨酸+酪氨酸(Phe+Tyr)。细鳞斜颌鲴肌肉共检出21种脂肪酸,其中7种饱和脂肪酸(SFA)、3种单不饱和脂肪酸(MUFA)、11种多不饱和脂肪酸(PUFA),分别占脂肪酸总量的25.22%、22.02%、37.76%;C20∶5n3(EPA)含量为11.87%,C22∶6n3(DHA)含量为11.55%。从营养分析结果来看,细鳞斜颌鲴是一种营养价值极高的食用鱼类。     

半咸水、淡水养殖刀鲚消化、抗氧化、非特异性免疫及代谢酶活力的比较分析

为探究刀鲚(Coilia nasus)在半咸水(盐度为8.7~12.5)和淡水养殖条件下消化、抗氧化、非特异性免疫及代谢能力的差异,本研究采用池塘套养方式,以同批次人工繁育的刀鲚1+龄鱼为研究对象,进行为期210 d的养殖实验。结果显示,半咸水养殖刀鲚(以下简称半咸水刀鲚)的生长速度显著大于淡水养殖刀鲚(以下简称淡水刀鲚) (P<0.05),其对蛋白质和淀粉的消化能力均高于淡水刀鲚,而对脂肪的消化有所减弱。其中,半咸水刀鲚的4种内脏器官的淀粉酶(AMS)活力均大于淡水刀鲚,但差异不显著(P>0.05);胃和肝中蛋白酶活力均显著大于淡水刀鲚(P<0.05),肝和盲囊中脂肪酶(LPS)活力均显著低于淡水刀鲚(P<0.05)。半咸水刀鲚的AMS、蛋白酶活力大小顺序均为盲囊>肠>胃>肝,而LPS活力大小顺序为肠>盲囊>胃>肝;淡水刀鲚的AMS、蛋白酶和LPS活力大小顺序均为盲囊>肠>胃>肝。半咸水刀鲚的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)活力及丙二醛(MDA)含量均显著升高(P<0.05),而过氧化氢酶(CAT)活力显著降低(P<0.05);其肝脏中碱性磷酸酶(AKP)和酸性磷酸酶(ACP)活力均显著低于淡水刀鲚(P<0.05),半咸水对刀鲚谷草转氨酶(AST)活力无显著影响,但会显著降低谷丙转氨酶(ALT)活力。研究表明,半咸水养殖条件不仅促进了刀鲚的生长,提升了刀鲚对蛋白质和淀粉的消化能力,还通过提高SOD和GSH-PX活力来提升刀鲚免疫力,减少外界环境威胁。综上所述,刀鲚更适合在半咸水中进行养殖,建议今后可用半咸水(盐度为8.7~12.5)养殖1+龄刀鲚。     

盐度对凡纳滨对虾肌肉中游离氨基酸含量的影响

通过逐渐升高盐度的方法,分别测定盐度为0、10、20、30和40时凡纳滨对虾肌肉中游离氨基酸(FAA)的含量,实验周期40 h。结果表明:在盐度0~40时,总游离氨基酸(TOFAA)、必需氨基酸(EAA)、非必需氨基酸(NEAA)和鲜味氨基酸(TAA)的含量都随盐度的增加而明显升高(P0.05);特别是当盐度从20增加到30时,肌肉中TOFAA、EAA、NEAA和TAA含量的增高幅度最明显。在凡纳滨对虾肌肉FAA中,含量最高的是甘氨酸(Gly),其次是脯氨酸(Pro)、精氨酸(Arg)和丙氨酸(Ala)。在盐度为0~40范围内,肌肉中主要的渗透压调节因子是甘氨酸(Gly)、脯氨酸(Pro)、精氨酸(Arg)、丙氨酸(Ala)和牛磺酸(Tau);而天冬氨酸(Asp)、丝氨酸(Ser)、缬氨酸(Val)、甲硫氨酸(Met)、异亮氨酸(Ile)、亮氨酸(Leu)和酪氨酸(Tyr)的含量在各盐度组未呈现显著变化(P0.05)。在淡水养殖凡纳滨对虾出售前的40 h,通过提高水体盐度来提高凡纳滨对虾肉质的鲜味是完全可行的。     

海州湾近岸长蛸不同组织的营养成分分析与评价

对海州湾近岸长蛸肌肉、肝胰脏和生殖腺3种组织的营养成分进行了分析.结果表明,3种组织中粗蛋白含量为13.1%～14.7%,其中肌肉>肝胰脏>生殖腺,肌肉干基粗蛋白含量比生殖腺中高6.69%(P<0.05);粗脂肪含量均较低(0.9%～1.2%),生殖腺>肝胰脏>肌肉;3种组织均含18种氨基酸,肌肉、肝胰脏和生殖腺中EAA/TAA值分别为41.06%、40.34%和46.23%,EAA/NEAA值分别为69.67%、67.62%和89.84%,氨基酸组成符合FAO/WHO(1973)参考模式标准;肌肉中多不饱和脂肪酸(PUFA)占脂肪酸总量的51.9%,其中,C22:6(DHA)、C20:5(EPA)和C20:4(AA)占PUFA总量的80.5%;肌肉中Fe和Zn两种微量元素含量较高,分别为6.07和5.95 mg/kg.     

金色鳜鱼与普通鳜鱼肌肉营养成分的比较分析

比较分析了金色鳜鱼选育群体与普通养殖鳜鱼肌肉的常规营养成分、氨基酸和脂肪酸的组成。结果显示:金色鳜鱼和普通鳜鱼的粗脂肪含量分别为0.91%、1.41%,差异具有统计学意义(P0.05);水分、灰分和粗蛋白含量差异不具有统计学意义(P0.05)。两群体17种氨基酸(不包括色氨酸)中除丝氨酸外组成基本一致,无统计学意义差异(P0.05);7种必需氨基酸(EAA)总量分别为6.52%和6.84%;鲜味氨基酸(DAA)含量较高,分别为6.68%和6.63%;必需氨基酸指数(EAAI)分别为86.76、88.77。EAA/TAA分别为39.40%、39.58%,EAA/NEAA的比分别为75.55%、76.25%。所含人体必需氨基酸总量及构成比例均符合FAO/WHO标准。基于氨基酸评分(AAS)的金色鳜鱼和普通鳜鱼的第一、第二限制性氨基酸均分别为缬氨酸、亮氨酸;基于化学评分(CS)的金色鳜鱼第一、第二限制性氨基酸分别为异亮氨酸、缬氨酸,普通鳜鱼第一、第二限制性氨基酸分别为苯丙氨酸+酪氨酸、异亮氨酸。肌肉中19种脂肪酸中除C16∶1外均无统计学意义差异,其中单不饱和脂肪酸含量(MUFA)分别为38.74%和39.02%,多不饱和脂肪酸含量(PUFA)分别为29.07%和28.84%、EPA+DHA含量较高(7.01%,7.06%)。综合分析认为,金色鳜鱼和普通鳜鱼肌肉均有较高营养价值,之间无统计学意义差异。     

津新红镜鲤肌肉和鱼皮营养成分分析与品质评定

对津新红镜鲤(Cyprinus carpio var. Jinxin red mirror)肌肉和鱼皮营养成分进行了测定分析。结果显示,津新红镜鲤肌肉(鲜样)中蛋白质含量为18.00 g/100 g、脂肪含量为7.40 g/100 g;肌肉中含有18种氨基酸,总量(TAA)为15.74 g/100 g,其中8种人体必需氨基酸(EAA)的含量为6.49 g/100 g,4种鲜味氨基酸的含量为5.86 g/100 g,分别占氨基酸总量(TAA)的41.23%、37.23%,必需氨基酸(EAA)与非必需氨基酸(NEAA)的比值为70.16%,符合FAO/WHO理想蛋白源评价标准;肌肉中富含镁、锌、硒等元素;肌肉中含有23种脂肪酸,饱和脂肪酸(SFA)占脂肪酸总量的25.41%,不饱和脂肪酸(UFA)占脂肪酸总量的74.59%,EPA和DHA的含量分别为0.132 g/100 g和0.360 g/100 g。津新红镜鲤鱼皮中β-胡萝卜素含量为0.861μg/100 g。     

长荡湖野生中华绒螯蟹肌肉营养成分的分析与评价

为了解长荡湖野生中华绒螯蟹(Eriocheir japonica sinensis)肌肉的营养成分,采用国家标准生化测定方法检测了30只蟹肌肉样本中水分、蛋白质、脂肪、灰分、氨基酸和脂肪酸的含量。结果表明,长荡湖野生蟹肌肉的水分含量为78.26%、蛋白质含量为13.00%、脂肪含量为0.62%、灰分含量为1.91%。氨基酸检测中共测出17种氨基酸,谷氨酸含量最高,半胱氨酸含量最低,总量(TAA)为每100g含16.14 g。其中,4种鲜味氨基酸(DAA)占氨基酸总量的40.15%;7种必需氨基酸(EAA)和10种非必需氨基酸(NEAA)分别占氨基酸总量的33.84%和66.16%,必需氨基酸指数(EAAI)值为102.71,符合优质蛋白源的标准。脂肪酸检测中共测出饱和脂肪酸(SFA)5种、单不饱和脂肪酸(MUFA)5种和多不饱和脂肪酸(PUFA)7种。脂肪酸含量SFA∶MUFA∶PUFA为1∶1.2∶2.3;PUFA/SFA为2.3。长荡湖野生蟹可作为优质蛋白来源,对人体具有一定的营养补充和保健作用,同时也可作为中华绒螯蟹新品种选育的优质亲本。     

盐度胁迫对三疣梭子蟹肌肉和血淋巴中游离氨基酸含量的影响

为探究不同盐度环境下三疣梭子蟹肌肉和血淋巴中游离氨基酸(free amino acids,FAAs)的含量及浓度的变化规律,明确FAAs的组成以及在盐度适应中发挥的作用,丰富FAAs在甲壳动物盐度适应领域的研究,为后续分子机理的研究提供依据,实验设定胁迫盐度分别为10、20、40、50,以正常海水(盐度33)为对照,用日立835-50型氨基酸自动分析仪测定三疣梭子蟹血淋巴与肌肉组织中游离氨基酸的组分,分析不同盐度环境下三疣梭子蟹肌肉和血淋巴中FAAs的含量及变化规律。结果显示,在正常海水中三疣梭子蟹血淋巴和肌肉中含量较高的FAAs主要为牛磺酸(Tau)、精氨酸(Arg)、甘氨酸(Gly)、脯氨酸(Pro)和丙氨酸(Ala)。盐度为10~50,梭子蟹肌肉和血淋巴总游离氨基酸(total free amino acid,TOFAA)的含量随盐度的增加而显著升高,非必需氨基酸(non-essentical free amino acid,NEAA)的含量随盐度的升高而上升,而必需氨基酸(essentical free amino acid,EAA)的含量变化不显著,因此,TOFAA在渗透压调节方面的作用主要取决于NEAA。发挥主要渗透压调节作用的FAAs为脯氨酸(Pro)、丙氨酸(Ala)、甘氨酸(Gly)、天冬氨酸(Asp)、谷氨酸(Glu)。Ala、Gly、Asp、Glu属于鲜味氨基酸(taste amino acid,TAA),研究表明,NEAA中的TAA在渗透压调节方面作用显著,Pro含量的升高对TOFAA含量的增加作用显著,盐度为40~50尤甚,表明Pro在梭子蟹高渗调节中发挥重要作用。     

星斑川鲽♀×圆斑星鲽♂杂交子代的生化组成分析与评价

对星斑川鲽(Platichthys stellatus)♀×圆斑星鲽(Verasper variegates)♂杂交的子一代(杂交鲽)肌肉营养成分进行分析测定,并与其亲本进行了比较。结果显示,杂交鲽的含水率和粗蛋白略低于双亲,粗脂肪含量介于二者之间;杂交鲽氨基酸总量、必需氨基酸总量及鲜味氨基酸总量均低于双亲,但EAA/TAA和EAA/NEAA均高于双亲,此外,杂交鲽肌肉中缬氨酸的含量明显高于双亲;脂肪酸含量方面,杂交鲽的EPA明显高于双亲,DHA比星斑川鲽也有所提高。     

Nutritional evaluation of rotifers in rearing tanks without water exchange during seed production of amberjack <Emphasis Type="Italic">Seriola dumerili</Emphasis>

We evaluated the nutrient contents of rotifers sampled from larval-rearing tanks (tank rotifers) without water exchange during the seed production of amberjack Seriola dumerili at three facilities (Kamiura, Kagoshima, and Miyazaki) and compared them with the nutrient contents of freshly enriched rotifers. Compared to the enriched rotifers, the lipid contents, especially neutral lipids and proportion of 22:6n-3, tended to decrease in the tank rotifers. These trends were clearer at Miyazaki where the tank rotifers were sampled before daily supplementation of microalgae (Nannochloropsis). Crude protein content of the tank rotifers did not decrease markedly although the proportion of lysine tended to decrease. Vitamin C and E contents of the tank rotifers decreased significantly only at Miyazaki. Calcium content of the tank rotifers increased at Kamiura and Miyazaki, and the increases in iron and manganese contents of the tank rotifers at Miyazaki and zinc content at Kagoshima were pronounced. These results suggest that the nutritional value of rotifers in larval-rearing tanks without water exchange can be maintained by appropriate supplementation of microalgae. The effect of certain minerals that became high in tank rotifers on subsequent larval development requires further investigation.     

Larval sea lamprey release two unique bile acids** to the water at a rate sufficient to produce detectable riverine pheromone plumes

The discovery that the olfactory system of the anadromous sea lamprey is extremely sensitive to two unique bile acids (petromyzonol sulfate [PS] and allocholic acid [ACA]) produced by stream-resident larval conspecifics has lead us to hypothesize that these compounds function as a migratory pheromone. Here, we test whether lamprey release these bile acids to the water in quantities sufficient for them to function as a long distance attractant. Five experiments were conducted. First, high performance liquid chromatography (HPLC) of liver extracts from all three life history stages of this species established that only larvae produce PS and ACA; parasites and maturing adults produced no identifiable bile acids. Large quantities of PS and ACA were found in larval gall bladders. Second, HPLC analyses of larval lamprey holding waters established that recently-fed larvae held in the laboratory release these bile acids to the water, with PS being released at a rate of approximately 16 ng h^–1 animal^–1 and ACA at 5 ng h^–1 animal^–1. Fasted animals released little bile acid. Third, an investigation of bile acid release routes demonstrated that larvae release bile acids primarily via their feces. Fourth, a study of the stability of ACA and PS in river water found both to have a half-life of a day. Finally, theoretical extrapolations using these data suggest that PS and ACA are present in picomolar concentrations in lamprey streams, a concentration within the detection range of adults. In conclusion, these data demonstrate for the first time in a fish that bile acid release rates and modes are adequate for these compounds to have pheromonal function.     

Bioaugmentation in the growth and water quality of livebearing ornamental fishes

Bacillus subtilis isolated from the intestine of Cirrhinus mrigala (Hamilton) was incorporated into the rearing water of Poecilia reticulata (Peters), Poecilia sphenops (Valenciennes), Xiphophorus helleri (Heckel) and Xiphophorus maculatus (Gunther) at four different concentrations (5 × 10⁸ cells ml⁻¹, 5 × 10⁷ cells ml⁻¹, 5 × 10⁶ cells ml⁻¹ and 5 × 10⁵ cells ml⁻¹) and its effect on fish growth performance and survival, water quality parameters and bacterial population of water were assessed. The results showed that the addition of bacterial cells in the rearing water resulted in greater survival and a faster growth rate and, hence, greater length and weight increments of the livebearers. The use of a bioaugmentor in the rearing water of the livebearing fishes resulted in significantly lower (P < 0.05) concentrations of dissolved organic matter and total ammonium nitrogen. The counts of motile aeromonads and total coliforms recorded in the water of bioaugmented tanks were also lower than that in the control tank. Bioaugmentation between 10⁶ and 10⁸ cells ml⁻¹ in the rearing water is sufficient in establishing a bioaugmentor and the use of a higher concentration of bacterial cells did not always lead to significantly better results.     

不同碳源对凡纳滨对虾育苗标粗水体生物絮团的结构、营养成分、细菌群落及其水质的影响

为研究凡纳滨对虾育苗标粗阶段生物絮团形成所需要的适合碳源,设计3种不同碳源添加组(葡萄糖组、淀粉组和蔗糖组),每个处理组设置3个重复,实验期20 d,以分析不同碳源添加后对水体生物絮团的形成、营养成分、细菌群落结构及水质指标的影响。结果显示,在碳源添加量均为投喂量的80%时,形成的生物絮团可有效调节水质,降低水体中的氨氮和亚硝酸盐氮水平。3个碳源添加组水样中氨氮、亚硝酸盐氮和硝酸盐氮浓度显著低于对照组,淀粉组水样中氨氮、亚硝酸盐氮和硝酸盐氮浓度显著高于葡萄糖组和蔗糖组;最终对虾存活率统计结果显示,葡萄糖组、淀粉组、蔗糖组和对照组分别为72.9%、54.2%、69.8%和44.3%;淀粉组的生物絮团沉降体积(BFV)显著低于葡萄糖组,蔗糖组BFV最高,在13～15 d后3组均趋于稳定;葡萄糖组和蔗糖组的粗蛋白含量均显著高于淀粉组,葡萄糖组和蔗糖组则差异不显著;葡萄糖组和蔗糖组生物絮团中组氨酸、精氨酸、蛋氨酸等必需氨基酸和天冬氨酸、谷氨酸、丙氨酸等非必需氨基酸含量都显著高于淀粉组;葡萄糖组、淀粉组和蔗糖组的必需氨基酸指数(EAAI)值分别为0.93、0.89和0.92。3种类型生物絮团在门级水平的细菌群落共有18余种,其中变形菌门和拟杆菌门在各组占有比例均最高,淀粉组拟杆菌门含量显著高于其他2组,蔗糖组浮霉菌门和放线菌门含量显著高于葡萄糖组和淀粉组。研究表明,添加不同碳源可影响水体生物絮团的形成、营养成分、细菌群落结构和多样性,不同程度地改善水质。以必须氨基酸指数及存活率为评价指标,则葡萄糖和蔗糖都是凡纳滨对虾育苗标粗水体中适宜的碳源选择。     

铜绿微囊藻和小球藻对水环境pH的影响

以盐碱池塘优势微藻铜绿微囊藻(Microcystis aeruginosa)、小球藻(Chlorella pyrenoidosa)为研究对象,采用正交实验方法,研究不同温度(20℃,25℃,30℃)和光照强度(2000 lx,4000 lx,6000 lx)组合条件下两种微藻对水环境pH的影响。结果显示,处于对数生长期的铜绿微囊藻和小球藻均能使水环境pH上升。在本实验范围内,不同温度和光照强度组合条件下,铜绿微囊藻的生长均能使水环境pH显著上升至9.50以上,在温度25℃、光照强度2000 lx条件下,藻密度达最大值1.1×10~7 cells/m L,水环境pH也达到峰值10.83;小球藻生长亦能使水环境pH的上升,并随温度升高、光照强度增强而增大,在温度30℃、光照强度6000 lx条件下,藻密度达最大值8.1×10~6 cells/m L,水环境pH也达到峰值7.73。通过ANCOVA分析,水环境pH和藻细胞密度呈正相线性相关,铜绿微囊藻水环境pH和藻细胞密度相关系数R~2=0.904,小球藻水环境pH和藻细胞密度相关系数R~2=0.903。与小球藻相比,同等藻密度的铜绿微囊藻更易使水环境pH显著上升(P0.01),是池塘养殖水体pH偏高的主要原因之一,本研究旨在通过控制藻相方式进行水环境调控,从而防止池塘pH偏高提供了基础数据。     

Microbially matured water: a technique for selection of a non-opportunistic bacterial flora in water that may improve performance of marine larvae

Before transfer to larval incubators, water was membrane filtered to remove >95% of the bacteria and then transiently maintained in a biofilter that promoted recolonization of the water by non-opportunistic bacteria. The process is termed microbial maturation of the water. Hypothetically the bacterial flora in the matured water should protect the marine larvae from colonization and proliferation by opportunistic bacteria. Testing of the hypothesis demonstrated 76% higher survival of yolk sac larvae of Atlantic halibut (Hippoglossus hippoglossus) in matured than in membrane filtered water. Proliferation of opportunistic bacteria was observed in the rearing water after hatching of turbot eggs (Scophthalmus maximus), but to a less extent in the microbially matured water. In the early phase of first feeding of turbot larvae, the matured water induced qualitative differences in the gut microflora. Significantly higher initial growth rate of the turbot larvae in the matured water affected 51% higher average weight of 13 days old larvae than in membrane filtered water. Algal addition to the matured water enhanced the larval growth further. The experiments conducted supported the proposed hypothesis that microbial maturation selects for non-opportunistic bacteria, which protects the marine larvae from proliferation of detrimental opportunistic bacteria.     

Natural food evaluation and water quality in zero water exchange culture of Litopenaeus vannamei fertilized with wheat bran

The aim of this study was to analyze the influence of organic fertilizer on the availability of natural food (plankton and benthos) and water quality. Two fertilization protocols were adopted using inorganic and organic fertilizers with shrimp (stocked treatment) and their controls (unstocked treatment). Experimental units consisted of 12 circular fiberglass tanks (500 l) with estuarine sediment, individual aeration and no water exchange. In stocked treatments were used 40 juveniles/m², and they were fed with 35% crude protein marine shrimp ration, three times a day. Under the organic fertilization protocol, the plankton showed higher abundance of Nitzschia and rotifers, the phytobenthos consisted mainly of Nitzschia, Amphiprora and Oscillatoria, the epibenthos was represented mainly by nematodes and rotifers, and the macro-invertebrates were mainly oligochaetes. In relation to inorganic fertilization, the plankton was represented mainly by Coscinodiscus and rotifers, the phytobenthos consisted mainly of Amphiprora and Oscillatoria, the epibenthos was represented mainly by nematodes and rotifers, and the macro-invertebrates were mainly oligochaetes. Dissolved oxygen was higher for organic fertilizer (6.16 ± 0.98 mg/l) than for inorganic (5.92 ± 1.19 mg/l) while the other water quality parameters did not present significant differences. Survival was similar in the two fertilization regimes (96.6%). Final body weight was 11.89 ± 1.73 g for the inorganic fertilizers and 12.28 ± 1.71 g for organic fertilizer. It is concluded that wheat bran showed good performance in the water quality without exchange, in the availability of natural food, and in the growth and survival of the shrimps in the microcosms.     

室内集约化养虾池以低频率运转水处理系统调控水质效果及氮磷收支

采用低频率运转循环水处理系统(含粗滤器、臭氧仪、气液混合器,蛋白分离器、暗沉淀池等)联用池内设施(微泡曝气增氧机与净水网)开展凡纳滨对虾室内集约化养殖实验。研究了养虾池以水处理系统调控水质效果及氮磷收支。结果表明,养虾水经系统处理后,NO₂-N(53.4%～64.5%)、COD_Mn(53.4%～94.4%)与TAN(31.6%～40.4%)被显著去除,有效改进虾池水质;养殖周期内未换水与用药,虾池主要水化指标均控制在对虾生长安全范围,7号实验池(100 d)与8号对照池(80 d)主要水化指标变化范围:DO分别为 5.07～6.70 mg/L和4.38～6.94 mg/L,TAN 0.248～0.561 mg/L和0.301～0.794 mg/L,NO₂-N 0.019～0.311 mg/L和0.012～0.210 mg/L,COD_Mn 10.88～21.22 mg/L和11.65～23.34 mg/L。7号池对虾生长指数优于8号池(80 d虾病暴发终止),单位水体产量分别为1.398 kg/m²与0.803 kg/m²。氮磷收支估算结果:7号与8号池饲料氮磷分别占总收入:氮93.70%与92.37%,磷98.77%与99.09%;初始水层与虾苗含氮共占总收入6.30%与7.63%,磷共占1.23%与0.91%。总水层(含排污水)氮磷分别占总输出:氮56.45%与59.86%,磷53.26%与55.79%;收获虾体氮磷分别占总输出:氮37.07%与31.94%,磷21.37%与13.11%。7号池饲料转化率较高;池水渗漏与吸附等共损失氮磷分别占总输出:氮7.00%与9.34%,磷25.37%与31.10%。实验结果表明,虾池以低频率运转循环水处理系统联用池内设施可有效控制水质与虾病,具较高饲料转化率。     

不同水温与饲料磷水平对日本沼虾生产性能、组织及水体磷含量的影响

为探讨不同水温与饲料磷水平对日本沼虾生产性能、组织及水体磷含量的影响,实验采用3×3因子设计,设定3个水温梯度(20、25和30°C)和3个饲料磷水平(1.1%、1.5%和1.9%),共9组(分别命名为20/1.1、 20/1.5、 20/1.9、 25/1.1、 25/1.5、 25/1.9、30/1.1、30/1.5和30/1.9),每组4个重复。虾饲养于室内循环系统中,养殖期为8周。结果显示,从水温来看,30°C组的终末体质量、特定生长率和增重率均显著高于20°C组,但与25°C组间差异不显著,而摄食量和饵料系数的变化趋势与此相反。此外,30°C组的磷保留率显著高于其他2组,且该组血淋巴磷含量显著高于25°C组,而与20°C组无显著差异。从饲料磷水平来看,1.9%磷水平组的终末体质量、增重率和磷保留率显著低于其他2组,而磷摄入量与饵料系数的变化趋势与之相反。1.9%磷水平组的特定生长率显著低于1.5%磷水平组,但与1.1%磷水平组差异不显著。此外,1.1%磷水平组全虾磷含量显著低于其他2组,且该组的血淋巴钙含量显著高于1.9%磷水平组,而与1.5%磷水平组无显著差异;1.5%磷水平组血清碱性磷酸酶活性显著高于1.1%磷水平组,但与1.9%磷水平组间无显著差异。水温和饲料磷水平之间的交互作用显著影响摄食量、磷摄入量、磷保留率、血淋巴磷含量及碱性磷酸酶活性,峰值分别发现于20/1.1、25/1.9和30/1.9、30/1.1、30/1.9及25/1.5组。另外,水体磷含量随时间延长显著升高,而20/1.5组水体磷含量极显著高于25/1.1组和30/1.1组。研究表明,当水温为30°C而饲料磷水平为1.1%时,日本沼虾的生长性能及饲料效率最优,同时其对水体中磷的排放量也较低。     

The fatty acid composition of Nereis diversicolor cultured in an integrated recirculated system: Possible implications for aquaculture

The potential of solid waste originating from a recirculated fish culture system, i.e. faecal material, uneaten food pellets and bacterial biofilms was examined as food source for the marine polychaete Nereis diversicolor. These polychaetes could be a valuable food for fish if they provide essential fatty acids to the fish. Therefore, we analysed the fatty acid profiles from feed and faecal materials, the sediment as well as the cultured organisms — fish and several batches of N. diversicolor — from an integrated recirculating aquaculture system.The major fatty acids (saturated, monounsaturated and polyunsaturated) for all analysed fish feed, fish and faeces samples were C16:0, C18:1 and C22:6 (n − 3), accounting for 48% to 57% of the fatty acids in the samples. The major fatty acids within the sediment were C16:0, C18:1 and C18:3 (n − 3), accounting for 61% of the total fatty acids. The samples of N. diversicolor revealed C16:0, C18:1 and C20:5 (n − 3) as the major fatty acids. Combined, they accounted for 56% of the total fatty acids detected within the worm samples.The results indicate that a recycling or even an upgrade of excreted feed nutrients such as fatty acids, which were otherwise discharged, can be achieved through integrated aquaculture combining fish and worm culture.