多种数据源下栖息地模型及预测结果的比较

由于多来源的海洋环境数据常以不同时间、空间分辨率呈现,并具有不同的误差,因此,有必要分析数据源的差异是否会对研究结果产生显著影响,是否会影响基于不同数据源估计的模型对其他数据的适用性。为此,本研究利用多个网站提供的叶绿素浓度与海表水温数据,采用线性回归与随机检验方法,分析了不同数据源对栖息地模型构建及其预测效果的影响。研究结果表明,不同数据源的数据之间常存在系统性偏差,从而使得模型参数的估计具有显著性差异,该模型不适合于其他数据源的数据;多源环境数据间的离散性反映数据存在随机误差,环境数据的随机误差将使模型结果具有随机性,因此本研究建议定量分析模型结果的不确定性,以使模型结果得到科学应用。     

中亚五国内陆渔业产业衰退析因及其重振策略探讨

中亚包括哈萨克斯坦、吉尔吉斯斯坦、塔吉克斯坦、土库曼斯坦、乌兹别克斯坦五国,是"丝绸之路经济带"的核心区域,内陆渔业资源禀赋雄厚,世界第一大湖里海以及第四大湖咸海均分布在域内。在前苏联时期中亚各国捕捞渔业和水产养殖发展态势良好,随着东欧巨变及前苏联政局陷入动荡直至解体,渔业生产急剧萎缩,至今虽有复苏但尚未能恢复到苏联时期的发展水平。本文主要基于我们前期研究基础以及FAO和世界银行等统计数据,提出对苏联解体后中亚各国渔业崩溃的原因解读,并探讨在"一带一路"框架下,中国和中亚各国可行的渔业合作方式以及重振中亚渔业的策略方法。     

长江口凤鲚雌雄成体营养成分分析与比较

对长江口雌性和雄性成体凤鲚(Coilia mystus)整体的营养成分和品质进行了分析与评价。结果显示,雌、雄凤鲚整体水分、粗蛋白、粗脂肪和灰分的质量分数分别为78.36%±1.41%、76.70%±1.20%,14.25%±1.05%、15.18%±0.12%,4.61%±1.78%、4.84%±0.27%和2.22%±0.38%、2.97%±0.64%,雌、雄间均不具有显著性差异(P0.05)。雌、雄均含有18种组成蛋白质的氨基酸,总量分别为66.20%±5.78%和65.93%±6.35%(质量分数,干样),其中8种必需氨基酸(EAA)总量分别是25.07%±1.93%和23.95%±2.21%,两者间不具有显著性差异(P0.05),分别占氨基酸总量的37.90%和36.33%,雌、雄凤鲚的必需氨基酸组成比例均符合FAO/WHO的标准。色氨酸是雌、雄凤鲚整体的第一限制性氨基酸,蛋氨酸+胱氨酸是第二限制性氨基酸,雌、雄凤鲚整体的EAAI分别为70.73和66.99,4种鲜味氨基酸总量分别为25.99%±2.53%和26.02%±2.3%(质量分数,干样)。雌性凤鲚的饱和脂肪酸(SFA)含量显著低于雄性(P0.05),而多不饱和脂肪酸(PUFA)含量则显著高于雄性(P0.05),单不饱和脂肪酸(MUFA)两者无显著差异(P0.05)。雌性凤鲚脂肪酸中EPA与DHA质量分数分别为5.70%±0.24%和10.15%±1.31%,显著高于雄性凤鲚的1.05%±0.40%和1.06%±0.44%。结果表明,长江口雌、雄成体凤鲚整体的氨基酸较均衡,而雌性凤鲚的脂肪酸营养更为丰富,比雄性凤鲚具有更好的食用价值与保健作用。     

Effect of fish meal replacement by Chlorella meal with dietary cellulase addition on growth performance,digestive enzymatic activities,histology and myogenic genes’ expression for crucian carp Carassius auratus

This study was conducted to investigate the effects of fish meal (FM) replacement by Chlorella meal (CM) with dietary cellulase supplementation on growth performance, digestive enzymatic activities, histology and myogenic genes’ expression in crucian carp Carassius auratus (initial body weight: 2.90 ± 0.02 g, mean ± SEM). Six isonitrogenous diets were formulated at two cellulase levels (0 and 2 g kg^?1). At each cellulase level, CM was added at three levels of 0, 533.1 and 710.8 g kg^?1 to substitute 0, 75 and 100% of dietary FM respectively. Each experimental diet was randomly assigned to triplicate groups with 25 juvenile fish per fibreglass tank for 8 weeks. Dietary CM substitution significantly increased growth, feed utilization, amylase activity and the expression of Myod, Mrf4 and Myf5, but reduced the Myog expression. Dietary cellulase addition increased hepatosomatic and viscerosomatic index, lipase activity and the expression of Mrf4, but reduced trypsin activity and the expression of Myog and Myf5. Dietary CM substitution enlarged the cell size and also caused some karyopyknosis in liver. Our results showed that CM could totally replace FM in diets; dietary cellulase supplementation at the level of 2 g kg^?1 played a subtle role in improving growth and feed utilization for crucian carp.     

盐度骤变对金钱鱼幼鱼鳃线粒体丰富细胞形态结构的影响

文章采用显微技术研究了盐度骤降(20盐度组投入5盐度组)、盐度骤升(20盐度组投入35盐度组)胁迫下,金钱鱼(Scatophagus argus)幼鱼鳃线粒体丰富细胞(Mitochondria-rich cells,MRCs)形态结构的变化.结果显示,低盐胁迫3 h MRCs长径[(9.517±1.390)μm]和短径...     

黑龙江地区鲤疱疹病毒3型的流行病学调查及其主要囊膜蛋白的抗原表位预测

2015-2016年对来自黑龙江地区46个养殖场送检的鲤鱼进行锦鲤疱疹病毒(Koi herpes virus,KHV)的分离鉴定,并应用DNAStar等软件对检出的阳性样本的主要囊膜蛋白(Major envelop protein,MEP)基因进行生物信息学分析。结果显示,KHV的检出率约为6.5%,3株阳性样本具有相同的MEP基因序列,称之为KHV-HLJ1516。MEP基因开放阅读框为771 bp,编码256个氨基酸,相对分子质量为28 280.58,等电点为8.40。对KHV-HLJ1516的MEP基因序列同源性分析表明,其与KHV-GZ11分离株仅有1个碱基不同,但并未导致氨基酸发生改变,碱基相似性为99%;而与HZ419分离株相比,KHV-HLJ1516的MEP基因有3个碱基发生突变,相应的氨基酸由Asn变为IIe。聚类分析结果显示,KHV-HLJ1516与KHV-GZ11处于同一分支,而HZ419位于另一分支。B细胞抗原表位预测结果显示,KHV-HLJ1516的MEP的抗原表位主要位于4~11,24~40,42~63,82~110,209~218,238~249氨基酸区段。     

干露胁迫对脊尾白虾(Exopalaemon carinicauda)呼吸代谢相关酶的影响

为了研究离水干露对脊尾白虾(Exopalaemon carinicauda)呼吸代谢能力的影响,以常温干露(22-24℃)、低温干露(4℃)2个实验组和1个对照组进行脊尾白虾干露胁迫实验,于胁迫后60、90、120、180 min取组织,测定琥珀酸脱氢酶(SDH)、细胞色素氧化酶(CCO)、延胡索酸还原酶(FRD)、乳酸脱氢酶(LDH)4种呼吸代谢酶活力和乳酸含量.结果显示,常温干露组肝胰腺、鳃、肌肉SDH和CCO活力随干露时间的延长而降低,且显著低于对照组(P＜0.05);FRD、LDH活力和肌肉乳酸含量随胁迫时间的延长呈先升高后降低趋势,且显著高于对照组(P＜0.05).低温干露组在胁迫60 min时,各组织呼吸代谢酶活力和肌肉乳酸含量与对照组无显著差异(P＞0.05),之后的变化趋势和常温干露组相同.常温干露组和低温干露组中肝胰腺和鳃SDH/FRD比值的变化幅度大于肌肉.研究表明,脊尾白虾通过提高无氧代谢来应对干露胁迫;低温干露下的脊尾白虾在胁迫早期可以维持有氧呼吸,肝胰腺和鳃比肌肉对干露胁迫更加敏感.     

Development of a quantitative PCR assay for monitoring Streptococcus agalactiae colonization and tissue tropism in experimentally infected tilapia

Streptococcus agalactiae has become one of the most important emerging pathogens in the aquaculture industry and has resulted in large economic losses for tilapia farms in China. In this study, three pairs of specific primers were designed and tested for their specificities and sensitivities in quantitative real‐time polymerase chain reactions (qPCRs) after optimization of the annealing temperature. The primer pair IGS‐s/IGS‐a, which targets the 16S‐23S rRNA intergenic spacer region, was finally chosen, having a detection limit of 8.6 copies of S. agalactiae DNA in a 20 μL reaction mixture. Bacterial tissue tropism was demonstrated by qPCR in Oreochromis niloticus 5 days post‐injection with a virulent S. agalactiae strain. Bacterial loads were detected at the highest level in brain, followed by moderately high levels in kidney, heart, spleen, intestines, and eye. Significantly lower bacterial loads were observed in muscle, gill and liver. In addition, significantly lower bacterial loads were observed in the brain of convalescent O. niloticus 14 days post‐injection with several different S. agalactiae strains. The qPCR for the detection of S. agalactiae developed in this study provides a quantitative tool for investigating bacterial tissue tropism in infected fish, as well as for monitoring bacterial colonization in convalescent fish.     

紫贻贝产卵前后转录组分析与相关基因的筛选

为探究紫贻贝(Mytilus galloprovincialis)雌性生殖相关基因在产卵过程中发挥的功能及其参与产卵活动的调控机制,对紫贻贝产卵前后的性腺组织进行了转录组测序分析。结果显示,紫贻贝产卵前后存在的差异表达基因为4060个,其中上调的基因数目为1488个,下调的基因数目为2572个。GO富集分析显示,这些差异基因主要参与生长、发育过程、生殖、生殖过程等生殖相关的生物学途径。KEGG富集分析显示,与产卵、生殖相关的信号通路包括TCA循环、GnRH信号通路、卵巢类固醇生成、雌激素信号通路、催产素信号通路、类固醇生物合成等能够被显著富集。荧光定量分析结果显示,促黄体生成激素β (LHβ)和基质金属蛋白酶14 (MMP14)基因表达水平显著升高,促性腺激素释放激素受体(GnRHR)、细胞色素P4503A酶(CYP3A)、细胞色素P45017A酶(CYP17A)基因表达水平显著下降。本研究利用转录组学分析了紫贻贝在产卵前后性腺组织转录水平的差异,揭示了紫贻贝性腺组织中参与调节产卵过程的主要途径和候选基因,为进一步阐明紫贻贝产卵活动的内在调控机制提供数据支撑,也为紫贻贝苗种繁育提供理论...