Country‐wide analysis of large wood as a driver of fish abundance in Swedish streams: Which species benefit and where?

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黑斑狗鱼形态性状对体重的影响效果分析

选取0^＋龄～4^＋龄黑斑狗鱼332尾,对其体长、体高、体宽、尾柄长、尾柄高、头长、头高、头宽、吻长、眼间距、口裂宽、口裂长和体重等13个性状进行测量。采用多元分析法分析体重和形态形状的关系。结果表明,黑斑狗鱼除0^＋龄头长与体重之间的相关系数未达到显著水平（P〉0．05）外,其它各形态性状与体重的相关系数均达到显著水平（P〈0．05）或极显著水平（P〈0．01）;经通径分析,不同年龄阶段各形态性状对体重的通径系数存在一定的差异,但体长和头高对体重的通径系数均达到显著水平,而且体长对体重的直接作用均最大,其余各性状均是通过体长间接的影响体重;决定系数分析结果表明,体长对体重的决定系数最大,其它性状主要通过体长影响体重;通径分析结果与决定系数分析结果的变化趋势一致;所选形态性状与体重的相关指数R2〉0．85,说明所选性状是影响体重的主要性状。应用逐步多元回归分析,经偏回归系数的显著性检验,建立以体重为因变量（Y）,各形态性状为自变量的多元回归方程,0^＋龄～4^＋龄黑斑狗鱼体重（Y）与形态性状参数的多元叵归方程分别为：LgY=-1．411＋0．395LgX8＋0．576LgX1＋0．092LgX1n＋0．538LgX7＋0．35LgX6;LgY=-4．132＋0．866LgX1＋0．102LgX】2＋0．083LgX7;LgY=一4．186＋0．772LgX1＋0．195LgX7;LgY=-2．542＋0．372LgX1＋0．185LgX3＋0．256LgX8＋0．23LgX7,;LgY=-4．585＋0．816LgX1＋0．178LgX7。经回归预测估计值与实际值间的差异不显著（P〉0．05）,该方程可用于黑斑狗鱼实际生产中,为黑斑狗鱼选种提供了理论依据和理想的测量指标。     

拟穴青蟹Cactus基因的cDNA克隆、序列及生物学功能

为获取拟穴青蟹Cactus基因cDNA全长、分析基本生物学信息,并初步探索其在病原物刺激下的免疫反应,实验采用RACE技术获得了拟穴青蟹Cactus(SpCactus)基因的cDNA全长序列,其cDNA全长为2035 bp,开放阅读框(ORF)1311 bp,编码436个氨基酸,分子量为46.01 ku。对蛋白理化性质进行预测发现,SpCactus为亲水性蛋白,等电点pI为4.91。经预测,SpCactus与其他物种的IκB蛋白具有相似的功能结构域。同源性比对结果显示,SpCactus与凡纳滨对虾和中国明对虾的Cactus蛋白同源性均高达62%,相似度为73%。系统进化树分析显示,SpCactus与甲壳动物聚为一支,与无脊椎动物聚为一大支。实时荧光定量PCR(RT-PCR)检测发现,SpCactus基因在拟穴青蟹不同组织中均有表达,肌肉中的表达量最高,其次为心脏、眼柄、血液和鳃,肝胰腺中的表达量最低。LPS和金黄色葡萄球菌刺激均能显著诱导SpCactus基因的表达。本实验成功扩增了SpCactus基因全长,并进行了生物信息学分析、理化性质预测,初步探讨了其生物学功能,为进一步研究其在免疫反应中的生物学功能提供参考依据。     

锦鲤尾鳍细胞系(KF-H)的建立

本研究建立了锦鲤(Cyprinus carpio)尾鳍细胞系。染色体数目、核型及DNA含量等实验,发现锦鲤体细胞和锦鲤培养细胞无显著性差异,染色体数目和DNA含量符合比例关系,建立的锦鲤尾鳍细胞系已形成了稳定的遗传性状,命名为KF-H。     

哲罗鲑形态性状与体重的相关性分析

从20个全同胞家系中随机测量了900尾哲罗鲑（Hucho taimen）幼鱼（1＋龄）的体重、全长、体长、叉长、体高、体宽、头长、头高、头宽、眼径、眼间距和吻长等11个形态性状,采用相关性分析、通径分析、多元分析,计算了以形态性状为自变量对体重为依变量的相关系数、通径系数和决定系数,定量分析了哲罗鲑形态性状与体重的相关性。11个形态性状与体重的相关性均达到显著性水平（R0．05）,去除体长、叉长及头长这三个与全长共线性的性状后,进行通径分析,发现眼径和吻长对体重的作用不显著,在剩下的6个性状中,全长对体重的决定作用最大,主要通过直接作用影响体重,其直接作用系数为O．5549,且大于其它5个性状的直接作用之和。这6个性状对体重的复相关系数为0．9643,表明其是影响体重的主要因素。应用多元回归分析,建立以体重为依变量,全长、体高、体宽、头高、头宽、眼间距为自变量的通径方程：log（体重）=-3．9130＋1．7039log（全长）＋0．2626log（体高）＋0．2740log（体宽）＋0．1765log（头高）＋0．3460log（头宽）＋0．262410g（眼间距）。以上通径方程为哲罗鲑亲本的选择和表型性状的理想测量提供了理论依据。     

EXTERNALITIES,INSTITUTIONS AND THE LOCATION CHOICES OF SHELLFISH PRODUCERS: THE CASE OF BLUE MUSSEL FARMING IN THE MONT-SAINT-MICHEL BAY (FRANCE)

ABSTRACT

Most marine aquaculture activities remain strongly dependent on coastal ecosystems. In the case of shellfish farming, this dependency is related mainly to water quality and to the various ecological interactions resulting from the dynamics of coastal food webs. Such ecological constraints have influenced the overall evolution of blue mussel farming in the Mont-Saint-Michel Bay, leading producers to negotiate collective arrangements regarding production capacity and techniques and to develop production strategies at the farm level. This article presents an analysis of the location choices of mussel farmers in the Mont-Saint-Michel Bay based on an empirical investigation conducted in 2002. A typology of farms with respect to their land structure is developed in which some farms choose to concentrate their activity in a single part of the bay while others distribute their activity more widely. Determinants of the location choices of each farm category, including distance to port, natural productivity differentials, and predation of mussel stocks, are analyzed. The role of the institutional arrangements allowing mussel farmers to develop these location strategies is also discussed.     

A review of production frontier analysis for aquaculture management

Abstract

This paper examines recent advances in production economics with special reference to efficiency measurement using production frontiers and its implications for aquaculture management. Compared with agriculture and other industries, the use of production frontiers in aquaculture is still very limited. However, in recent years several frontier applications in aquaculture have appeared in the literature, suggesting potential applications of these techniques in aquaculture. A synopsis of stochastic frontier production function model and data envelopment analysis (DEA), the two most popular approaches to efficiency measurement, is presented, followed by a review of recent frontier studies in shrimp, carp and tilapia production. The paper concludes with a brief discussion of future development and prospects of frontier applications for aquaculture management.     

Rainbow trout (Oncorhynchus mykiss,Walbaum ) develop a more robust body shape under organic rearing

Prolonged exposure to captive conditions has led to the development of a rainbow trout ‘farmed’ phenotype, which is different from that of wild trout. Selection for desirable productive traits in hatcheries has resulted in the development of some morphological traits that are maladaptive in nature. The recent development of organic aquaculture, guided by the well‐being of the fish, could potentially produce a new farmed phenotype that would be more adaptive in nature. In this study, rainbow trout reared in intensive and organic farms were compared by means of shape analysis, to detect patterns of shape variation associated with rearing environment. The results of this study highlight a significant effect of the rearing method on rainbow trout shape: organically reared trout showed a higher body profile, in particular in the head and trunk regions, shorter median fins and a deeper caudal peduncle. A combined effect of density and habitat complexity could have contributed to the observed shape differences: in organic rearing systems, lower densities and steady water could increase territoriality and aggressive interactions, promoting body designs more functional in rapid attacks and escapes.     

池蝶蚌组织蛋白酶L1-like基因的克隆及表达特征分析

为了解淡水贝类是否存在组织蛋白酶L的亚型及其亚型的免疫相关作用,本实验利用已构建的池蝶蚌血细胞全长c DNA文库,筛选获得与之同源的EST序列,结合RACE技术进一步克隆了池蝶蚌一个新的组织蛋白酶L基因的c DNA全长,命名为Hs Cts L1-like基因(Gen Bank登录号为KF015273)。该序列全长为1280 bp,5′-非翻译区(5′UTR)为31 bp,3′-非翻译区(3′UTR)为256 bp,开放阅读框区(ORF)为993 bp,编码330个氨基酸,预测蛋白相对分子量为36.86 ku,理论等电点为6.23。序列分析结果显示,Hs Cts L1-like与其他软体动物相对应序列具有共同结构特征,包含信号肽、前肽抑制域和成熟肽三部分,在其他物种中已鉴定的Cts L签名序列标签(ERF/WNIN、GNFD、GCXGG和QCHN等)在Hs Cts L1-like中均可找到。其氨基酸序列同缢蛏Cts L1(AGL33704.1)同源性最高,达67%;与报道的三角帆蚌Cts L(ADV03094)和池蝶蚌中另一个Cts L(AEX88474)仅均为52.91%;系统进化分析表明,Hs Cts L1-like与缢蛏、长牡蛎和合浦珠母贝的Cts L1聚为一分支,推测Hs Cts L1-like属于Cts L家族中的亚型1。实时荧光定量PCR(q RT-PCR)检测显示,Hs Cts L1-like m RNA在肝脏中表达量最高,其次是卵巢和精巢。注射鳗弧菌后,血细胞和肝脏Hs Cts L1-like m RNA转录水平显著升高,暗示其是一个免疫有关的基因,参与了池蝶蚌的先天免疫应答反应。     

线粒体COI基因条形码在鲿科鱼类物种鉴定中的应用

为了探讨线粒体COI基因作为DNA条形码在中国鲿科(Bagridae)鱼类物种鉴定中的有效性,以及系统发育中的适用性,本研究对4属11种鲿科鱼类进行PCR扩增,获得48条线粒体COI基因序列,同时从Gen Bank筛选获得8种鲿科鱼类的12条COI基因序列进行分析。19种鲿科鱼类的COI基因序列特征显示:长度为674 bp的COI序列片段平均碱基组成为24.82%A,30.44%T,27.10%C和17.64%G,碱基组成呈现明显的AT偏倚性(55.26%),具有硬骨鱼类的线粒体COI基因的碱基组成的典型特征。核苷酸位点中有变异位点226个,简约信息位点195个,单一信息位点31个,转换颠换比为3.35。19种鲿科鱼类的种内、种间和属间平均遗传距离分别为0.0041、0.1136和0.1268,种间遗传距离平均为种内遗传距离的27.7倍。在本研究中,鲿科鱼类所有的物种均形成单系,在物种鉴别上与形态学分类结果基本一致,然而鲿科的4个属中只有鱯属形成单系,黄颡鱼属、属和拟鲿属均未形成单系,其进化地位需要进一步研究。线粒体COI基因作为条形码可有效对鲿科鱼类进行物种鉴定,也为鲿科的系统发育提供了参考。