中国沿海常见鲳属鱼类耳石形态研究

本研究采集中国沿海常见五种鲳属鱼类并对其耳石进行系统的多元形态学描述与比较。耳石形态在整体轮廓、边缘以及前部表现出明显的种间差异,展现了耳石形态的种内特异性。随着基因隔离与种间分化,鲳属鱼类耳石也逐渐变薄且基叶、翼叶更为发达。上述观察到的种间耳石形态差异与鱼体本身生活的水层以及温度联系紧密。96.6%的判别成功率也证明鲳属鱼类耳石显著的种间差异,表明形态学方法可以作为鲳属鉴别的有效手段之一。     

基于矢耳石形态的平鲉属鱼类鉴别及研究方法比较

分析了青岛胶州湾铠平鲉(Sebastes hubbsi)、花斑平鲉(Sebastes nigricans)和许氏平鲉(Sebastes schlegelii) 3种平鲉属鱼类的矢耳石形态特征,探究基于矢耳石形态鉴别3种鱼类的可行性.以8个耳石形状指标和37个椭圆傅里叶系数进行的单因素方差分析结果基本一致,显示铠平鲉与许氏平鲉的耳石形态差异最大,铠平鲉与花斑平鲉间差异最小.利用耳石形状指标、椭圆傅里叶系数、耳石形状指标与椭圆傅里叶系数相结合的方法,对3种鱼类的综合判别率均可达95%以上,判别分析散点图可明显将3种鱼类区分开.耳石长介于4~7 mm的3种鱼类小规格组与2龄及以上成鱼组耳石样本的判别结果一致,表明针对不同发育阶段平鲉属鱼类,基于耳石形态的种类鉴别均是可行的;仅使用椭圆傅里叶系数鉴别3种鱼类时综合判别率虽高达100%,但难以快速定位3种鱼类耳石形态间,在统计上差异显著而实际上微小的形状差异所在;而使用耳石形状指标和椭圆傅里叶系数联合判别,综合判别率亦高达99%,且能快速找出3种鱼类耳石在矩形趋近率、形态因子、面密度等的形态差异.研究表明,耳石形状指标和椭圆傅里叶分析联合判别是平鲉属鱼类种类鉴别及耳石形态差异分析的有效手段.     

基于矢耳石形态的平鲉属(Sebastes)鱼类鉴别及研究方法比较

分析了青岛胶州湾铠平鲉(Sebastes hubbsi)、花斑平鲉(Sebastes nigricans)和许氏平鲉(Sebastes schlegelii)3种平鲉属鱼类的矢耳石形态特征,探究基于矢耳石形态鉴别3种鱼类的可行性。以8个耳石形状指标和37个椭圆傅里叶系数进行的单因素方差分析结果基本一致,显示铠平鲉与许氏平鲉的耳石形态差异最大,铠平鲉与花斑平鲉间差异最小。利用耳石形状指标、椭圆傅里叶系数、耳石形状指标与椭圆傅里叶系数相结合的方法,对3种鱼类的综合判别率均可达95%以上,判别分析散点图可明显将3种鱼类区分开。耳石长介于4~7mm的3种鱼类小规格组与2龄及以上成鱼组耳石样本的判别结果一致,表明针对不同发育阶段平鲉属鱼类,基于耳石形态的种类鉴别均是可行的;仅使用椭圆傅里叶系数鉴别3种鱼类时综合判别率虽高达100%,但难以快速定位3种鱼类耳石形态间,在统计上差异显著而实际上微小的形状差异所在;而使用耳石形状指标和椭圆傅里叶系数联合判别,综合判别率亦高达99%,且能快速找出3种鱼类耳石在矩形趋近率、形态因子、面密度等的形态差异。研究表明,耳石形状指标和椭圆傅里叶分析联合判别是平鲉属鱼类种类鉴别及耳石形态差异分析的有效手段。     

中国近海棱梭群体形态学和耳石形态学研究

为研究棱梭不同地理群体间的形态差异,使用多元统计分析方法对采集自金门、厦门、虎门、湛江、北海和防城港6个地点邻近海域的棱梭群体样本的形态和矢耳石形态两方面进行比较研究。对棱梭样本的形态研究结合传统形态学和地标形态学开展,对矢耳石的形态研究则将传统耳石形态分析法和椭圆傅里叶分析法相结合,形态和耳石形态数据的分析结果相似。主成分分析结果表明从28个棱梭形态量度指标提取的前8个主成分累积贡献率为65. 868%,从85个耳石形态指标提取的前23个主成分的累积贡献率为79. 290%,根据临界值85. 000%可以推断这6个棱梭群体间形态和耳石形态上的差异不能够单独依靠少数指标来判断;聚类分析的结果总体显示出群体间差异与地理距离等因素相关联的分布规律;在判别分析中形态学量度指标的综合判别正确率为75. 9%,而耳石形态学指标的综合判别正确率略低,为69. 3%;对棱梭形态量度指标的单因子方差分析显示湛江棱梭群体与其他群体在形态上存在显著差异的量度指标较少。栖息地环境、饵料组成和海流等可能是导致形态学差异和耳石形态差异形成的主要因素。另一方面,理化因子的相似性和群体间的交流会减弱群体间形态和耳石形态的差异。     

大黄鱼Pseudosciaena crocea(Richardson)耳石的轮纹形成周期及其年龄鉴定问题

为了满足渔业经济不断增长的需要,就必须对鱼类,特别是重要经济种类的生活习性进行系统的深入研究。因此,确定鱼类年龄鉴定的方法,从而依据年龄的鉴定,按不同生命阶段来研究鱼类的生活规律,就成为最基本的问题了。 关于大黄鱼的年龄鉴定问题,尚未见有专门进行研究的报导。在支献记载上,福建水产研究所和广东水产研究所曾先后用耳石和鳞片估计大黄鱼的年龄,但并未对年龄鉴定的依据与方法进行分析。Irie 则对黄花鱼属的耳石轮纹形成周期问题进行了一些观察。 为了探讨大黄鱼年龄鉴定的确切方法,自1958年秋季起,我们展开了这方面的工作,系统地逐月搜集了大黄鱼耳石、鳞片、脊椎骨等项可能供作鉴别年龄的材料。观察结果以耳石上显示的轮纹最为清晰而有规律,因此,我们选用耳石作为鉴定大黄鱼年龄的研究对象。本文着重以浙江舟山及其邻近海区的材料为主,对大黄鱼耳石轮纹形成周期、轮纹性状以及鉴别年轮的主要标志等加以分析与讨论。此外,对于春、秋宗幼鱼第一个年轮的形成时期与鉴定方法也进行了探讨。 在我们所研究的材料中,1957年5月份的部分耳石是浙江温州水产局供给的;1960年5-7月份的部分幼鱼耳石是浙江省渔业资源调查委员会所借给;未观察耳石年龄的幼鱼长度组成的季节变化资料则是沙学绅和杨纪明同志供给的。中国科学院地质古生物研究所曾协助我们设计了耳石磨片机,均此志谢。 除作者等外,全部耳石磨片工作是滕文法同志担任的,黄颂芳同志参加了资料的统计,林汝范同志协助了资料的搜集工作。 本文承张孝威教授热情指导,作者谨致谢忱。     

石鲽野生群体和养殖群体遗传多样性的ISSR分析

采用简单序列重复区间(ISSR)技术,对石鲽的3个野生群体——青岛群体(QD)、威海群体(WH)、莱州群体(LZ)和一个养殖群体(YZ)进行了遗传多样性研究.结果表明,从60个ISSR引物中筛选出8个ISSR引物对四个群体的基因组DNA进行扩增,共获得183个重复性好且5谱清晰的位点,4个群体的多态位点比例为48.1%~50.8%,Shannon多样性值为15.68~18.53,群体内个体间遗传相似度为0.9053~0.9189,群体间的遗传距离为0.0055~0.0173.同其他鱼类相比,石鲽群体的遗传多样性水平较低.用UPGMA方法构建的群体进化树显示,WH群体和LZ群体遗传距离最近,首先聚在一起,两者然后与YZ群体聚类,最后与QD群体相聚.利用基因分化系数进行遗传变异来源估算,结果表明石鲽群体96.47%的遗传变异来源于群体内,群体间的遗传变异仅占3.53%,不同群体间的遗传相似度较大.     

渤、黄海大泷六线鱼耳石微化学特征与群体判别

为探究中国近海大泷六线鱼(Hexagrammosotakii)耳石微化学成分特征及群体分化状况,采集了连云港、青岛、威海、烟台、秦皇岛、大连、丹东7个野生群体和1个威海养殖群体的大泷六线鱼样本。利用LA-ICPMS技术测定耳石中的微量元素,以微量元素与钙的比值进行了分析,结果显示大泷六线鱼耳石中, Na/Ca、Sr/Ca、Fe/Ca、Mg/Ca较高,而Mn/Ca、Ba/Ca、Zn/Ca、Li/Ca较低。耳石1龄前元素比值的组间比较(S-N-K检验)结果显示:Na/Ca、Sr/Ca、Fe/Ca在群体间具显著性差异(P<0.05)。耳石边缘区元素与环境中元素比较发现,Li、Mn元素在耳石中富集程度较大,Sr在耳石的中元素含量远远大于水环境中的浓度,说明耳石中的元素沉积与海水中元素并不是简单的线性关系。判别分析结果显示:耳石1龄前元素指纹的判别分析结果表明,大泷六线鱼群体的判别成功率为63.0%,判别正确范围为30.0%～80.0%,耳石边缘区元素的判别正确率为57.1%,判别正确范围20.0%～80.0%,秦皇岛群体有高的判别成功率80.0%。耳石元素指纹可以用于不同大泷六线鱼群体的...     

深海鱼的“独特”耳朵

在海洋中，大约有90％的地方是阳光无法到达的，那里一片漆黑。深海鱼类是否会有更为敏锐的听力，帮助它们在黑暗中捕捉猎物、寻找配偶、躲避敌人？一项新研究表明，深海鱼类进化出了不同寻常的耳朵，以适应深海环境。例如，几种生活在中美洲水下1000米深处的太平洋辐鳍鱼，它们的耳石上长出了又长又硬的茎状结构，其主要成分是碳酸钙。     

虾类遗传多样性的研究现状

同工酶技术已经被广泛应用于虾类群体遗传学及标记辅助选择育种等研究方面.同工酶电泳显示对虾有相应的亚群差异,暖水性虾类的遗传多样性水平高于冷温性种类;连续分布的且在不同生活史阶段所处的栖息地环境变化幅度大的种类往往表现出较低的遗传多态性,虾类群体的多态位点比例和杂合度都较低,养殖群体比野生群体更低.但同工酶电泳技术往往检测不出一些"隐性"或"中性"变异而低估了遗传多样性水平.随着分子生物学技术的发展,从20世纪90年代开始,虾类遗传多样性的研究逐渐向线粒体DNA和核DNA的多态性方向发展.限制性片断长度多态性(RFLP)在虾类线粒体多倍型、物种标记以及比较野生和养殖群体线粒体COI 基因的多态性比较等方面应用普遍.随机扩增多态性(RAPD)技术主要应用于虾类不同地理群体遗传多态性调查,养殖群体与野生群体之间、养殖群体世代之间的遗传多态性比较,该技术得到的虾类遗传多样性水平高于同工酶电泳技术.扩增片断长度多态性(AFLP)技术在虾类中主要应用于遗传连锁图谱的构建,有关虾类的AFLP遗传多样性分析的报道不多.利用AFLP技术对连续选育群体的遗传多样性研究显示,随着选育世代的增加,选育群体的遗传多样性呈现下降趋势,但随着选育时间的延长,群体之间的分化逐渐降低,群体的遗传结构开始趋于稳定,成为一个品系.单一重复序列(SSR)技术主要用于标记种群遗传特异性、不同地理群体间以及野生和养殖群体间的遗传多样性差异.DNA序列分析技术特别是线粒体序列分析技术近年来在虾类遗传多样性研究中的应用逐渐增多.mtDNACOI、mtDNA12S rRNA和mtDNA16S rRNA的基因序列差异被应用于形态相近物种的鉴别、亚属分类、确定个体间亲缘关系和野生与养殖群体间的遗传多样性差异等.为了实现对虾类种群遗传差异的更深入了解,人们把种群遗传结构的研究和系统地理学相结合,即用分子系统地理学的方法来研究遗传谱系空间分布的历史特征,通过种群遗传结构的分析来探讨种内系统地理格局的形成机制、系统发育关系以及现有分布特征,并结合种群的地理分布状况来发现和验证与其相关的地质事件,追溯和揭示种群的进化历程.从育种、养殖以及资源保护的角度出发,人们开始研究野生群体的种质基因库,希望根据群体遗传结构确定合理的增殖策略,制定科学的保护措施,确保虾类养殖业的持续发展.     

基于环境DNA技术的夏季东海鱼类物种多样性研究

为了解东海海域主要鱼类群落的种类组成,监测和保护其多样性,本研究利用环境DNA技术对东海鱼类进行物种多样性分析.通过海水样本的采集,环境DNA提取、扩增和高通量测序分析,从东海14个站点的环境DNA样本中共检测出2纲,23目,29科,42属,44种海水鱼类,大部分种类在东海传统渔业资源调查中均有出现.其中,相对丰度较高...     

The management of the blue whiting fishery as complex social-ecological system: The Galician case

In Europe, 88% of fish stocks are being fished beyond Maximum Sustainable Yield and 30% of stocks are outside of biological limits. The blue whiting fishery is also following a consistent trend of a declining, and the EU recently adopted a 93% quota decrease for this species. Despite the abundant literature related to genetic aspects of population structure of aquatic resources, few studies have specifically addressed the link between fisheries management and population genetics. Given potential differences in the behavior of different subpopulations, population genetics has great relevance in the correct interpretation of the evolution of stocks. Ignoring the congruence of spatial scales between the population structure of fish species and management units can result in reduced productivity and local reduction of populations.     

Validation of growth zone deposition rate in otoliths and scales of flathead mullet Mugil cephalus and freshwater mullet Myxus capensis from fish of known age

Flathead mullet Mugil cephalus and freshwater mullet Myxus capensis are important components in South African estuarine fish communities and fisheries, but there is little information on their age and growth or age validation. This study validated the periodicity of growth zone formation in sectioned sagittal otoliths and scales of fish of known age that had been at liberty for 10 years. For both M. cephalus and M. capensis, the number of growth zones counted on otolith sections did not differ significantly from the known age of the fish. There were significantly fewer growth zones on scales than the known age of both M. cephalus and M. capensis. Growth zone deposition rate could therefore be validated as annual for otoliths but not for scales of the two species. It is recommended that future ageing studies focus on otoliths rather than scales.     

Spatial variation in elemental composition of otoliths of three species of fish (family Sparidae)

Determining the nursery habitat of fishes that have moved from estuarine nursery habitats is difficult. The elemental fingerprints of otoliths of three species of sparids were determined to investigate their utility as a natural tag of the nursery habitat. Juvenile Pagrus auratus (snapper), Rhabdosargus sarba (tarwhine) and Acanthopagrus australis (bream) were collected from two sites in each of 15, six and three estuaries, respectively, and their otoliths analysed by solution-based inductively coupled plasma-mass spectrometry. Significant differences in otolith chemistry were found for all three species of juveniles collected from different estuaries. The same patterns among estuaries were not seen for all species, although it was not possible to sample the same sites within an estuary for all species. For bream, significant differences in otolith chemistry were found among all three estuaries, whereas for tarwhine the six estuaries were separated into three groups. For snapper, a number of estuaries could be separated, but there was some overlap for other estuaries. All three species were collected from the same site within one estuary and their otoliths analysed. Significant differences were found among species, but the implication of this finding remains unclear as the three species show differences in microhabitat use and may also differ in age. Because the elemental fingerprints of juveniles vary among estuaries or groups of estuaries, the nursery or recruitment estuary of adult fish could now be determined by analysing the juvenile region of adult otoliths. Thus, connectivity between estuaries and open coastal populations could be determined. Such information will have major implications for fisheries management because it will provide information on the distance that fish have moved from their recruitment estuary and the number of estuaries that contribute to each adult population.     

蟹类线粒体DNA的研究与应用

线粒体DNA作为理想的分子遗传标记已被广泛用于蟹类种群遗传学和进化遗传学的研究,并取得了许多有意义的结果。本文阐述了蟹类线粒体DNA分子生物学的研究进展,重点介绍蟹类线粒体DNA序列的研究概况及其多态性在蟹类系统学、种群识别、起源和进化、地理分化等研究中的应用情况。     

大黄鱼(Pseudosciaena crocea)岱衢洋选育群体和官井洋养殖群体的遗传差异分析

应用RAPD技术对大黄鱼岱衢洋选育群体和官井洋养殖群体的遗传差异进行研究,选取15条10bp随机引物,共检测出96个RAPD位点。结果表明,岱衢洋选育群体的多态位点比例为33.33%,平均杂合度为0.3008,Shannon多样性信息指数为0.0879,群体内个体间平均遗传相似系数为0.9079,平均遗传距离为0.0921;官井洋养殖群体的多态位点比例为43.75%,平均杂合度为0.3298,Shannon信息指数为0.1221,群体内个体间平均遗传相似系数为0.8784,平均遗传距离为0.1216。大部分遗传变异(93.52%)存在于群体内,少部分遗传变异(6.48%)存在于群体间。两群体间的Nei氏标准遗传距离为0.0123。以上分析表明,大黄鱼官井洋养殖群体的遗传多样性水平高于岱衢洋选育群体,但两个群体都处于较低的遗传多样性水平,需要对大黄鱼的种质资源进行科学管理和保护,以避免遗传多样性下降。     

Insights into the diet of a poorly known species: pygmy killer whale Feresa attenuata from Cape Verde,West Africa

Despite having a worldwide distribution in tropical waters, knowledge on pygmy killer whales Feresa attenuata, including diet, is poor, with only a few studies carried out to date. The presence of otoliths and beaks in stomachs that have been examined indicate that the diet of F. attenuata includes squid, octopus and fish. In this study, the stomach contents of two F. attenuata recently stranded in Cape Verde, West Africa, were examined. A variety of fish hard parts and otoliths were recovered, in addition to the upper beak from an unidentified cephalopod and the remains of some marine arthropods. Lanternfish (Myctophidae) and deepbody boarfish Antigonia capros were identified from otoliths and comprised 95.4% of prey items. Whereas the sizes of the myctophids in the two whale stomachs were similar, those of other prey items differed. The findings provide important information on the diet of F. attenuata in the Cape Verde region.     

Genetic diversity and population structure of the golden cuttlefish,Sepia esculenta (Cephalopoda: Sepiidae) indicated by microsatellite DNA variations

The golden cuttlefish, Sepia esculenta Hoyle, 1885 (Cephalopoda: Sepiidae) is a valuable and important fishery resource for China, Japan and Korea. This fishery has experienced severe population decline largely due to overexploitation in past decades. To provide guidelines for fisheries management, we estimated genetic diversity and population structure across four locations along the coast of Japan and one location in China (a total 281 individuals) using nine microsatellite DNA loci. Sepia esculenta showed high genetic variability with mean allele richness ranging from 15.8 to 21.4, and mean heterozygosity from 0.80 to 0.90. Weak but significant genetic differentiation was present and the F_ST value was 0.020 across all five populations. The useful information obtained in this study will offer insights into how to fine‐tune conservation and fishery management measures for this species and resource in the future.     

Growth changes in plaice,cod, haddock and saithe in the North Sea: a comparison of (post-)medieval and present-day growth rates based on otolith measurements

Fishing effort has strongly increased in the North Sea since the mid-19th century, causing a substantial reduction in the population size of exploited fish stocks. As fisheries research has developed simultaneously with the industrialisation of the fisheries, our knowledge of population dynamics at low levels of exploitations is limited. Otoliths retrieved from archaeological excavations offer a unique opportunity to study growth rates in the past. This study compares historical and present-day growth rates for four commercially important demersal fish species. A total of 2532 modern otoliths (AD 1984–1999) and 1286 historical otoliths (AD 1200–1925) obtained from archaeological excavations in Belgium and Scotland were analysed. Comparison of the growth patterns between eras revealed a major increase in growth rate of haddock, whereas growth changes were not observed in saithe and only in the smaller size classes of plaice and cod. Comparison of our results with literature data indicates that the observed growth rate changes in plaice and cod occurred within the 20th century. Apparently the onset of industrialised fisheries has not greatly affected the growth of plaice, cod and saithe populations in the North Sea. This result contradicts the expectation of density-dependent limitation of growth during the era of pre-industrialised fishing, but is in agreement with the concentration hypothesis of Beverton (Neth. J. Sea Res. 34 (1995) 1) stating that species which concentrate spatially into nursery grounds during their early life-history may ‘saturate’ the carrying capacity of the juvenile habitat even though the adult part of the population is not limited by the adult habitat.     

海洋浮游甲壳类分子系统学研究进展

回顾海洋浮游甲壳类系统学研究的基础上，综述了生化水平和DNA(mtDNA和核DNA)水平的分子系统学研究现状。分子标记中DNA序列分析最为常用，其次是RFLP和RAPD分析，mtDNA主要应用于分类学、群体遗传学、种间分子进化和系统发育重建研究，而核DNA则应用于科以上较高阶元的系统发育和种内、近缘种间的遗传结构和遗传分化研究。最后对存在的问题和应用前景进行了展望。     

Can the Movements of Barramundi in the Fly River Region, Papua New Guinea be Traced in their Otoliths?

To determine whether the concentrations of heavy metals in fish otoliths could be used to infer the fish's movement into water contaminated by heavy metals, we collected barramundi Lates calcarifer from two sites below the outfall from a large copper mine. It was first demonstrated that otolith Sr concentration could be used to separate the marine and freshwater life phases. Twelve elements were then examined (in particular Cu, Mn, Zn, Cd and Pb) in the otoliths by laser-ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Cadmium concentrations were rarely above the detection level of the instrument. There were low concentrations of Cu in the otoliths of most fish during the freshwater phase of their life history. Three fish out of 10 had higher levels of Cu at some ablations, coinciding with higher concentrations of both Zn and Pb. However, further analysis found no correlation between the Cu concentration of replicate ablations in the same growth zone to those with initially higher Cu values. Copper concentration in the otoliths did not rise during the period the fish were in freshwater, despite the concentration of dissolved Cu in the water being several times greater than in the lower estuary and adjacent coast.These results and other data from recent studies of heavy metals in fish tissues suggest that very little of the dissolved Cu in the Fly River is in the form of free ions that can be adsorbed across the gills and into the blood and the otoliths. It can be concluded that otoliths are not a good indicator of the history of barramundi movements into water contaminated with heavy metals. Our data support recent studies that suggest that the concentration of many elements, such as Cu, may vary in the endolymph around the otolith and thus may be attached to the calcium-binding proteins that form the matrix around the aragonite. Hence, high concentrations of heavy metals in some ablations may be related to the relative amount of aragonite and protein in each ablation rather than reflect environmental differences.