金鳙和黑鳙的肌肉营养成分分析及评价

采用国标(GB)检测方法,依据FAO/WHO的评价规定,对2010年发现于常德珊珀湖后经人工选育的金鳙和2015~2016年采样于常德珊泊湖的黑鳙(Aristichthys nobilis)进行肌肉营养成分分析和评价。结果表明,金鳙肌肉鲜样的水分、粗蛋白、粗脂肪、灰分水平分别为76.1%、20.6%、0.52%、1.1%,黑鳙的相应指标为76%、19.8%、0.48%、1.2%,其中两者间粗脂肪含量有显著性差异。金鳙和黑鳙的肌肉干样中17种氨基酸总含量分别为88.69 g/100 g和87.68 g/100 g、鱼类必需氨基酸含量为43.2 g/100 g和42.63 g/100 g、呈味氨基酸含量为32.52 g/100 g和32.32 g/100 g,没有显著性差异。两者肌肉氨基酸含量高低的排序也一致,含量最高的均为Glu,其次为Asp、Lys、Leu,含量最低的为Pro;必需氨基酸中含量最高的是Lys、Leu,最低的是Met。两种鳙鱼间除2种含硫氨基酸(Met、Cys)和组氨酸(His)含量有显著性差异外,其他氨基酸含量基本一致。从AAS和CS评分值可见,两者的限制性氨基酸均为Val、Ile或Thr。两者的必需氨基酸指数(EAAI)为80.47和80.13。研究说明,人工选育的金鳙具有与天然水域鳙鱼相当的营养品质。     

鳙异源雌核发育子代的形态学研究

本研究在已成功利用鳙(Aristichthys nobilis)(♀)×兴国红鲤(Cyprinus carpio Var.Xingguo)(♂)远缘杂交诱导鳙异源雌核发育的基础上,测定了鳙异源雌核发育子代及其母本鳙和父本兴国红鲤3组实验鱼的7项可量性状,计算其框架系数,并采用单因素方差分析、判别分析、主成分分析和聚类分析对三组鱼框架系数的差异和距离进行了分析。结果显示3组鱼多项框架系数间均具显著差异,雌核发育子代较母本表现为体型更高,头更长。判别分析能将3组鱼明显判别分为3个区域,其中雌核发育子代和兴国红鲤的判别准确率均为100%,母本鳙群体判别准确率为94.4%,总判别准确率为97.9%。主成分分析结果显示,可提取2个主成分,其中主成分1能解释64.504%的变异,主成分2能解释21.292%的变异,二者合并能解释85.796%的变异。聚类分析表明雌核发育子代形态学可量性状指标更接近于母本鳙,与父本兴国红鲤距离较远。本研究结果表明雌核发育后,鳙异源雌核发育子代主要可量性状与双亲产生显著差异,但更接近于母本。     

贵阳红枫湖鲢、鳙的食性研究

鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)是滤食性鱼类,具有净化水体的作用.从2007年开始,贵阳市每年向红枫湖投放500万鲢、鳙进行水体富营养化的治理.为了分析红枫湖鲢、鳙对饵料资源的利用情况,在2010年10 -11月研究了鲢、鳙的摄食强度,在2011年5-6月研究了鲢、鳙的摄食强度、食物组成及比例等方面.结果表明:鲢、鳙的总摄食率分别为98.00％、96.93％;冬季鲢、鳙的饱满指数范围分别为44.13～99.79％、46.12 ～ 127.00％,春季鲢、鳙的饱满指数范围为53.27～ 245.14％、49.94～ 234.32％,鲢、鳙春季的饱满指数显著高于冬季.在食物组成上,鲢的肠道有36种藻类,鳙的肠道有31种藻类.从个数比例来看,鲢、鳙食物中浮游植物占个数组成比例的99％以上,浮游动物很少;但从重量比例来看,浮游动物在鲢、鳙体内分别占(50.993±2.214)％、(90.799 ±2.321)％.选择性指数E表明鲢对蓝藻门的浮游植物有较大的选择性.     

不同营养型水库对鳙形态性状和风味物质的影响

为探究不同水体营养型对鳙（Aristichthys nobilis）生长和风味形成的影响,选择富、中、贫营养型水库的鳙,测定其体质量、形态性状和挥发性风味物质。结果显示：不同营养型的水库对鳙体质量和形态性状有一定的影响,富营养型水库鳙体质量、全长、头长、吻长、背吻距、尾鳍长、尾柄高、体高、体宽显著低于中、贫营养型水库鳙,并且中营养型水库鳙全长、体长、背吻距、尾柄长显著高于贫营养型水库鳙;不同营养型水库鳙体质量和形态性状的回归方程相关系数R²达到0.9以上,其中全长和体高是主要影响因素;不同营养型水库鳙肌肉共鉴定出33种挥发性风味物质,其中贫营养型水库鳙肌肉所含挥发性风味物质种类最多,且共有挥发性风味物质基本以贫营养型含量最高。总体来看,中营养型水库适合鳙的生长,而贫营养型水库有利于风味物质的形成。     

鳙慢沉性饲料加工及其蛋白营养需要研究

采用单因素梯度实验设计方法,研究双螺杆挤压膨化加工鳙(Aristichthys nobilis)慢沉性饲料的制作工艺,并通过饲养实验确定鳙幼鱼对饲料蛋白的适宜需求量。结果显示:饲料加工过程中物料的水分含量、脂肪含量和机筒温度对鳙饲料的下沉速度(SV)和糊化度有显著影响。当物料水分含量控制在25%、脂肪含量控制在7%～9%和机筒温度控制在90→115→130℃时,鳙饲料具有糊化度高、下沉速度慢的特性,适合鳙的摄食需求。在此工艺基础上,以酪蛋白和白鱼粉为主要蛋白源,制作蛋白质含量分别为20%、25%、30%、35%、40%和45%的6种配合饲料,饲养初始重6.0 g的鳙90 d,以增重率(WG)和特定生长率(SGR)为主要指标,评价饲料蛋白质水平对鳙生长的影响。结果表明,随着饲料蛋白质水平的升高,鳙的增重率和特定生长率均增加,当饲料蛋白水平为35%时达到峰值。采用二次曲线模型分析,确定鳙对饲料蛋白质的适宜需求量为34.65%～34.88%。     

高密度黄颡鱼—鳙养殖池塘浮游生物种群与理化因子的变化研究

以高密度的黄颡鱼(Pelteobagrus fulvidraco)-鳙(Aristichthys nobilis)分隔养殖池塘为研究对象,分析养殖期间(2013年4月—10月)池塘浮游生物和水体理化因子的变化情况。结果显示,池塘水体温度、p H、DO和总氮指标在养殖期间存在显著差异(P0.01)。Duncan's多重比较显示,温度在6—8月显著高于其他时间(P0.05);总氮在7—9月的含量显著升高(P0.05);氨氮和亚硝态氮在8—10月的含量明显升高(P0.05)。池塘浮游生物的变化表现为:枝角类和桡足类物种数随养殖时间的延长而逐渐减少,其中秀体溞属(Diaphanosoma)占优势;轮虫物种数呈上升趋势,其中臂尾轮虫属(Brachionus)占优势;原生动物物种数在各月份之间差异不明显,以球吸管虫属(Sphaerophrya)为优势种;藻类物种数呈先上升再下降的趋势,其中绿藻门(Chlorophyta)种类占优势,其次为裸藻门(Euglenophyta)种类。基于Dice相似系数的UPGMA聚类和Pearson相关系数的MDS排序均显示池塘水体中浮游生物群落在整个养殖期间可分为2大类,4、5、6、7月各样本聚在一起,8、9、10月各样本聚在一起,表现为前4个月(4—7月)相似性高,而后3个月(8—10月)相似性高;说明池塘浮游生物的群落结构随养殖时间延续发生了改变。     

长江宜昌江段和东洞庭湖鲢、鳙饵料生物组成及季节性变化

为了研究鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)饵料生物组成及季节变化,分析了2016年7月-2017年3月在长江宜昌江段及东洞庭湖不同季度采集的84尾鲢和65尾鳙的肠道内含物。结果显示:鲢、鳙在长江宜昌江段摄食的饵料生物种类分别是55种和48种,在东洞庭湖分别是55种和43种。根据相对重要性指数(IRI),鲢、鳙的主要饵料生物均为枝角类。鲢、鳙食物组成呈现季节变化,鲢在长江宜昌江段春季、夏季、秋季和冬季的主要饵料生物分别是硅藻门、枝角类、枝角类和硅藻门,在东洞庭湖分别为枝角类、蓝藻门、枝角类和桡足类;鳙在长江宜昌江段春季、夏季、秋季和冬季的主要饵料分别是枝角类、枝角类、枝角类和硅藻门,在东洞庭湖分别为枝角类、枝角类、枝角类和桡足类。     

长江中游鳙群体的微卫星遗传多样性分析

为了解长江中游鳙（Aristichthys nobilis）群体的遗传特征,利用12对微卫星引物对长江中游石首、监利和长沙3个鳙群体的遗传多样性和遗传结构进行了分析。结果显示:12个微卫星位点中有8个为高度多态位点,4对为中度多态位点,群体的观察杂合度（Ho）为0.398～0.778,期望杂合度（He）为0.425～0.919,多态含量信息（PIC）为0.371～0.907,3个群体遗传多样性较高。95.60%的遗传变异来自群体内,4.40%来自群体间,群体间的遗传分化程度较低(F_st=0.044),石首和监利群体的遗传分化最小(F_st=0.002 53),遗传距离最近（d=0.031 9）,监利和长沙群体的遗传分化指数和遗传距离均最大(F_st=0.023 69,d=0.076 6)。结果表明长江中游三个群体具有较高的遗传多样性,长江中游干流群体与长沙群体间的遗传分化较小。     

草鱼-鳙-鲫零换水养殖对池塘环境影响

为深入了解草鱼(Ctenopharyngodon idella)-鳙(Hypothalmichthys nobilis)-鲫(Carassius auratus)零换水池塘运行情况,比较其与常规养殖池塘的理化因子差异,进而探索其零换水机制,本研究以草鱼-鳙-鲫零换水养殖池塘为实验组,草鱼-鳙-鲫普通养殖池塘为对照组,进...     

鳙鱼不同组织基因组DNA提取方法的探讨

分别采用试剂盒和常规苯酚/氯仿抽提法提取新鲜的鳙鱼肌肉、肝脏、尾鳍以及用乙醇保存的3种组织基因组DNA,并对其进行综合分析。结果表明,对3种组织的新鲜样品2种方法均能提取高质量的DNA,而用乙醇保存的3种组织,DNA样品质量最好的是尾鳍,其次是肌肉,肝脏最差;总的来看,试剂盒法提取的DNA纯度较好,但是浓度低,而苯酚法得到的DNA浓度高,质量好,且相对成本低。综合比较,苯酚/氯仿抽提法提取乙醇保存的尾鳍组织基因组DNA是一种行之有效的方法,可以在鱼类分子研究中推广应用。     

太湖梅梁湾大型生态控藻围栏内鲢鳙的生长特征

富营养化湖泊围栏养殖鲢（Hypophthalmichthys molitrix）、鳙（Aristichthys nobilis）控制蓝藻水华在生物操纵示范中得到了广泛应用。在2004和2005年,研究了太湖梅梁湾生态修复区内大型生物控藻围栏中鲢鳙的季节生长特征,分析了影响其生长的因素。结果表明,鲢鳙生长受养殖密度的影响...     

Effect of stunting of juvenile bighead carp Aristichthys nobilis (Richardson) on compensatory growth and reproduction

The study was conducted to determine if stunting of young bighead carp Aristichtys nobilis (Richardson) would affect subsequent growth and reproduction. Juveniles (3 g each) were stocked directly in cages (control) in a lake or stunted in tanks for 6, 12, 18 or 24 months before being stocked in cages. Initially, body weights and lengths of stunted carp in cages were significantly lower (P<0.05) than those of the control fish. The carp stunted for 6, 12 and 18 months showed growth compensation, although their weights and lengths were slightly lower than those of the control fish. The body weight and length of fish stunted for 24 months were the lowest throughout the rearing period. Sexual maturation occurred only in the control fish and those stunted for 6 and 12 months. However, the onset of gonad maturity was delayed significantly (P<0.05) in males stunted for 12 months and in both groups of stunted female fish. The relative fecundity (44 000–56 000 eggs per kg body weight) and number of 3‐day‐old larvae produced per female (78 000–89 000) did not differ significantly among the three treatments (P>0.05), but production was somewhat lower in fish stunted for 12 months.     

养鳖池中种植水葫芦和搭养鲢鱼对改善水质效果的研究

使用2口面积2000㎡的池塘养鳌,在池塘中种植水葫芦并搭养鲢鱼,以期净化、改善养殖水质.使用2口面积相同的池塘作为对照.对比养殖试验进行了4个月,期间每隔10d测定COD,NH3-N,N02-N、DO、悬浮物(SS)等水质指标,并观察鳌的摄食和疾病情况.结果表明,在养鳌池中种植水葫芦和搭养少量鲢鱼,有利于改善水质减少鳌...     

Cu2+、Pb2+、Cd2+、Cr6+对鳙胚胎和仔鱼的急性致毒效应

研究了Cu2+、Pb2+、Cd2+、Cr6+ 4种重金属对鳙胚胎发育及仔鱼存活的影响.试验结果表明,在试验浓度范围内,除0.5、1.0 mg/L的Cd2+可促进胚胎发育速率外,其余3种重金属均不同程度地减慢胚胎孵化速率;受精卵孵化率明显低于对照组;初孵仔鱼出现不同程度的畸形;Cu2+、Pb2+、Cd2+、Cr6+对鳙仔鱼的毒性强度为Cu2+>Cd2+>Pb2+>Cr6+.根据试验数据求得4种重金属对鳙仔鱼的24、48、72、96 h的LC50值及安全质量浓度.     

Differences in swimbladder volume between Baltic and Norwegian spring-spawning herring: Consequences for mean target strength

Fish swimbladders, where present, contribute most to the scattering of sound by fish, as measured by the target strength (TS). The volumes of the swimbladders of two different European stocks of Atlantic herring were compared to consider the effect on estimates of TS. Swimbladder volumes of Baltic and Norwegian spring-spawning herring (Clupea harengus) were measured, together with individual herring fat content. Swimbladder volumes were found to differ significantly between the two herring stocks. Baltic herring have a larger swimbladder volume, which is suggested to be associated with the fish's low fat content, which in turn may be linked to its specific energy budget and the low salinity of the Baltic Sea. A buoyancy model that considered the different salinity conditions and fat proportions was used to evaluate the observed differences in swimbladder volume. The swimbladder volume data were subsequently used to model the mean target strength as a function of depth and growth pattern. Backscattering of the swimbladder was modelled using the modal-series-based deformed-cylinder model (MSB-DCM), describing the swimbladder as a gas-filled, elongated prolate spheroid. The fish body component was modelled as a fluid-filled ellipsoid using the distorted wave Born approximation (DWBA). Modelling results support a different TS-to-size relationship for Baltic herring, with a stronger echo, due to the larger swimbladder. Depth- and length-dependent TS relationships based on the model results are suggested.     

Target strength estimation of black porgy Acanthopagrus schlegeli using acoustic measurements and a scattering model

ABSTRACT:   Black porgy are hatched and released in marine ranching areas in Japan, Korea and Taiwan to maintain fisheries resources in coastal areas. If acoustic methods are used for field surveys, target strength ( TS ) information on the species is needed to convert acoustic data to biomass density. Target strength of black porgy ( Acanthopagrus schlegeli ) 15.5–32.9 cm fork length (nine individuals) was measured at 38 and 120 kHz (split beam) by ex situ measurements (cage and fishhook methods) of living fish, a tethered method with shock-frozen fish, and an acoustic scattering model, the Kirchhoff ray mode (KRM) model based on fish morphology. The ex situ TS -to-fork length ( FL , cm) relationships were TS _38kHz = 20log₁₀ FL  − 64.6 ( r  = 0.77) and TS _120kHz = 20log₁₀ FL  − 65.2 ( r  = 0.70). The values for the KRM model were TS _38kHz = 20log₁₀ FL  − 64.8 ( r  = 0.88) and TS _120kHz = 20log₁₀ FL  − 65.4 ( r  = 0.80). The agreement between the ex situ measurements and the KRM model for the mean TS was very good. In contrast, the results for the tethered method ( TS _38kHz = 20log₁₀ FL  − 69.3 [ r  = 0.42]) differed markedly from the other two methods, perhaps because of the effects of the shock-freezing procedure in air. The results of the ex situ measurements and scattering model provide basic information for studying TS and conducting acoustic surveys of black porgy, even though the tethered method must be modified.