我国裸胸鳝属鱼类新记录种——奥迪萨裸胸鳝(Gymnothorax odishi)形态与线粒体基因组分析

为完善我国裸胸鳝属鱼类物种信息,研究报道了采集于海南省陵水县裸胸鳝属鱼类新记录种——奥迪萨裸胸鳝(Gymnothorax odishi)。该物种仅于2018年在东印度孟加拉湾首次发现, 目前世界其他海域均无记录。针对采集的奥迪萨裸胸鳝进行详细的外部形态特征分析, 并从分子水平对该裸胸鳝进行线粒体全基因组测序。结果显示, 奥迪萨裸胸鳝主要特征为体型粗壮, 体棕褐色, 吻端至鳃孔区域分布橘黄色斑点, 眼睛后缘存在黑色斑块, 鳃孔边缘黑色, 身体无其他条带或斑纹; 上颌齿、中央齿均单行, 下颌齿两行, 椎骨式为4-52-135。线粒体基因组方面, 奥迪萨裸胸鳝线粒体全长为16 580 bp, 由13个蛋白编码基因、22个tRNA基因、2个rRNA基因和1个非编码控制区组成, 基因组结构特征与其他脊椎动物相似。基于12个蛋白编码基因构建的海鳝科鱼类分子系统进化树上, 奥迪萨裸胸鳝与匀斑裸胸鳝(Gymnothorax reevesii)、淡网纹裸胸鳝(Gymnothorax pseudothyrsoideus)、疏条纹裸胸鳝(Gymnothorax reticularis)及小裸胸鳝(Gymnothorax minor)聚在一起; 基于COI基因构建的裸胸鳝属鱼类分子系统进化树, 奥迪萨裸胸鳝与匀斑裸胸鳝、淡网纹裸胸鳝、肝色裸胸鳝(Gymnothorax hepaticus)及黄纹裸胸鳝(Gymnothorax monochrous)等聚为一支。遗传距离方面, 奥迪萨裸胸鳝与目前世界上其他裸胸鳝的遗传距离范围为0.082~0.263,均大于最小物种鉴定遗传距离0.020,揭示奥迪萨裸胸鳝在形态与分子水平均为区别于其他裸胸鳝的独立物种。研究结果表明我国海域也有奥迪萨裸胸鳝分布, 为新记录种, 为我国裸胸鳝属鱼类的系统分类及物种名录更新提供分类基础。     

4种裸胸鳝的分子遗传多样性和亲缘 关系的RAPD 分析

采用29个随机引物,对海南近海及西沙的野生群体黄边裸胸鳝(Gymnothorax flavimarginatus)、云纹裸胸鳝(Gym-nothorax chilospilus)、波纹裸胸鳝(Gymnothorax undulatus)及细斑裸胸鳝(Gymnothorax fimbriatus)的基因组DNA进行了RAPD分析,并用UPGMA法对这4种裸胸鳝进行聚类分析。研究结果表明:(1)黄边裸胸鳝、云纹裸胸鳝、波纹裸胸鳝及细斑裸胸鳝4种裸胸鳝群体内遗传多样性都较高,其多态位点比率分别为68.65%、57.00%、50.80%、67.42%,平均杂合度分别为0.222 1%、0.207 4%、0.166 6%、0.221 2%,表明南海野生裸胸鳝遗传变异水平较高,种质资源状况良好;(2)4种裸胸鳝种间遗传距离及聚类分析表明,黄边裸胸鳝与细斑裸胸鳝遗传距离最近(0.340 6);黄边裸胸鳝与云纹裸胸鳝的次之(0.386 8);云纹裸胸鳝与波纹裸胸鳝的最远(0.531 2)。(3)在7个引物中,有区分云纹裸胸鳝、波纹裸胸鳝及细斑裸胸鳝的特异性片段,可用于这些裸胸鳝的鉴定。     

我国近海裸胸鳝属鱼类新记录种——黏裸胸鳝（Gymnothorax mucifer）形态与分子系统学研究

本研究于2020-2021年在福建省厦门市近海水产市场采集到4尾黏裸胸鳝样品,为中国大陆近海新记录种。此前,该物种仅在澳大利亚、夏威夷等地有分布记录,并被认为是蠕纹裸胸鳝同种异名。本研究对采集的黏裸胸鳝进行详细形态特征分析,结合DNA条形码COI基因进行分子鉴定及系统进化关系分析。黏裸胸鳝的主要鉴别特征：体为黄棕色,头部前端淡紫色,身体布满细长、稀疏、弥散的树枝状不规则棕色斑纹,斑纹颜色靠近尾部加深加粗,形成网格状;臀鳍边缘白色,近尾部变为一列连续白色斑点;全长为体长的1.01倍,为头长的8.00～8.39倍;上颌齿每侧8～10个,下颌齿每侧14～20个,中央齿细长,均为单行;总椎骨数为117～139,平均椎骨式为6-47-130。基于COI基因分析,黏裸胸鳝与蠕纹裸胸鳝的遗传距离为0.074,大于Herbert设定的2%(0.020)作为区分不同物种最小遗传距离,表明两者应为不同的物种。形态上,两种裸胸鳝也存在差异特征,如黏裸胸鳝的斑纹较细长、稀疏、不明显,头部前端偏淡紫色,臀鳍白色边缘近尾部断裂成系列连续白色斑点;蠕纹裸胸鳝的斑纹粗大明显、颜色较深,头部前端黄白色,臀鳍白色边缘连续...     

中国裸胸鳝属10种鱼类分子系统发育关系的16SrDNA分析

为了阐明南中国海裸胸鳝属(Gymnothorax)鱼类系统进化情况,利用聚合酶链式反应扩增目的产物,将其连接到T载体后,并对其序列进行测定,共得到9种裸胸鳝属鱼类线粒体16S ribosomalDNA(16S rDNA)基因的部分序列,采用多个生物软件对序列变异和碱基组成进行分析,计算了Kimura2-parameter遗传距离,转换/颠换比等遗传信息指数,下载基因库中16SrDNA基因的同源序列,以鳗鲡属(Anguilla)的花鳗鲡(Anguilla marmorata)为外群构建NJ(Neighbore-Joining)、MP(MaximumParsimony)和ME(Minimum Evolution)系统进化树。根据所得分子数据并结合形态学特征推论如下:(1)在所研究的10种裸胸鳝鱼中共有516个位点、其中143个核苷酸位点存在变异(27.7%);(2)序列变异的转换/颠换比值的平均值为3.441;相对遗传距离数据表明斑颈裸胸鳝(G. margaritophorus)和网纹裸胸鳝(G. reticularis)差异最大(0.177),褐祼胸鳝(G. hepaticus)与布雷顿氏裸胸鳝(G. breedeni)差异最小(0.022);(3)NJ树、ME树表明裸胸鳝属内部存在3个平行进化的姐妹分支,分支内部的种类组成与地理分布无关。     

中沙群岛春季珊瑚礁鱼类资源组成的初步研究

2003年5月采用延绳钓和底层刺网在中沙群岛珊瑚礁水域进行了1个航次的鱼类资源调查。两种作业投入的捕捞努力量分别为延绳钓5620钓、底层刺网16120m,单次作业努力量延绳钓80~600钓、底层刺网600~1200m。捕获鱼类105种,渔获量1067尾2645.76kg,其中延绳钓34种计134尾2294.32kg,底层刺网共86种计933尾351.44kg。按岛礁平均,渔获率和单位捕捞努力量渔获量(CPUE)延绳钓为2.38尾.(100钓)-1、40.82kg.(100钓)-1,底层刺网为57.88尾.(1km)-1、21.80kg.(1km)-1。捕获的主要经济种类有鲨鱼、裸胸鳝、石斑鱼、笛鲷、裸颊鲷、鱼参科鱼类和大眼鲷等。     

军曹鱼染色体组型分析

为了解军曹鱼(Rachycentron canadum)的细胞遗传学特征,采用植物血球凝集素(PHA)、秋水仙碱胸腔注射,取头肾细胞经空气干燥法制片,分析了军曹鱼染色体核型。结果表明,军曹鱼核型为:2n=48=48t,染色体总臂数(NF)为48。     

双斑东方鲀染色体核型分析

鱼类的染色体核型分析是鱼类遗传学研究的基础,作为我国重要养殖品种的双斑东方鲀(Takifugu bimaculatus)尚未发现有染色体核型的相关报道.采用体内注射植物血球凝集素(PHA)及秋水仙素法制备了双斑东方鲀头肾组织染色体标本并分析其核型.结果表明,双斑东方鲀二倍体染色体数为2n=44,其染色体臂数为NF=62,核型公式为12m+6sm+26t.通过比较分析推测2n=44应该是东方鲀属的染色体基础核型,而其染色体核型的高度保守可能是东方鲀属鱼类易于发生种间杂交的主要原因之一.     

鮸状黄姑鱼染色体核型的研究

采用体内注射PHA和染色体常规制片方法对状黄姑鱼 (NibeamiichtheoidesChu,Lo &Wu)的核型进行了研究 ,结果表明状黄姑鱼二倍体染色体数目为2n=48,核型为2n=48t ,臂数NF=48。本文还就鱼类的染色体核型演化趋势进行了探讨。     

夏牙鲆(♂)与牙鲆(♀)人工杂交的细胞遗传学初步研究

于2004年11～12月在青岛薛家岛养鱼场采用夏牙鲆(Paralichthysdentatus)的精子与牙鲆(Paralichthysolivaceus)的卵子实施了多次人工杂交实验,并进行了父本母本鱼类个体、子代的染色体制片观察和细胞中DNA相对含量的流式细胞仪检测。结果表明,夏牙鲆染色体数为48,核型为2n=48t、臂数NF=48;子代的染色体数和核型与父母本的一样,也为2n=48t;子代的细胞中DNA的相对含量也表明其为二倍体。因此,可以明确其为杂交的后代,而不是雌核发育。     

日本蟳核型分析

以鳃、肝胰腺、心脏、精巢、成熟卵、各期胚胎及溞状幼体等为材料,采用空气干燥法对日本(女寻)(Charybdis japonica)的染色体数目和核型进行了研究.结果表明,发育期的精巢最适宜进行日本(女寻)染色体计数,用眼点期之后的胚胎和溞状幼体制片,适宜做核型分析.日本(女寻)染色体的数目是2,n=114,n=57.核型分析显示,日本(女寻)有中部着丝粒染色体(m)共计17对(第1～17号),亚中部着丝粒染色体(sm)7对(第18～24号),亚端部着丝粒染色体(st)仅1对(第25号),端部着丝粒染色体(t)共计32对(第26～57号).日本(女寻)的核型公式为:2 n=114=34m+14sm+2st+64t,染色体臂数NF=164,未能发现异形性染色体的存在.     

Trophic relationships in tidepool fish assemblages of the tropical Southwestern Atlantic

Trophic studies are fundamental to understanding the dynamics of assemblages and functional roles of species within ecosystems, contributing to the identification of factors responsible for the organization and structure of communities. This study aimed to analyse the trophic organization of tidepool fish assemblages in the tropical Southwestern Atlantic, based on the underlying idea that food resources are not limiting and that trophic guild formation is not driven by food competition. Diets were based on feeding index values of food categories for 12 representative species collected in six tidepools (20º49′ S, 40º36′ W) at quarterly intervals (2005 to 2007). The main food categories were small crustaceans, polychaetes and macroalgae. Multivariate techniques evidenced two multispecific trophic guilds: small‐prey carnivores, including Bathygobius soporator, Bathygobius geminatus, Malacoctenus delalandii and Halichoeres poeyi, and herbivores, including Sparisoma axillare and Acanthurus bahianus. Other species presented significantly different diets and were classified into the following guilds: omnivores feeding on filamentous algae and copepods (Abudefduf saxatilis); large‐prey carnivores (Labrisomus nuchipinnis); omnivores feeding on polychaetes and filamentous algae (Stegastes fuscus); and polychaete feeders (Ahlia egmontis). Gymnothorax funebris and Gymnothorax moringa were classified as carcinophagores and piscivores, respectively. Trophic organization appears related to species convergence toward the use of abundant food resources, driven by a combination of factors allowing some resource partitioning through inter‐specific differences in consumer size, microhabitat, behavior, and trophic specialization.     

对虾池悬浮颗粒附着细菌的研究

用5个实验围隔研究了对虾池悬浮颗粒上的附着细菌,结果表明:附着细菌数量波动在0.65×104～23.49×104个/cm3之间,平均为(4.57±3.64)×104个/cm3,占水体细菌总数的1.47%×1.41%(0.28%～8.73%).附着细菌数为1、2、3、4个的附菌颗粒占总附菌颗粒的比数分别为40%、27%、15%及11%,多于4个附着细菌的附菌颗粒数仅占总附菌颗粒数的7%;总悬浮颗粒中的附菌颗粒所占比例为52%;附着细菌数与水体总悬浮颗粒数关系最为密切,与水温及总细菌数也具有显著相关性,但与水层POC及DOC含量却未呈现显著的相关性.     

顶点成分分析算法在端元数目估计中的应用研究

确定端元数目是混合像元分解中端元提取的前提,目前端元数目主要还是通过图像处理人员目视判读来获取。 在研究顶点成分分析算法的原理和端元光谱之间在大多数情况下相互独立的基础上,提出一种基于顶点成分分析算法的端元数目估计方法。 通过在不同端元数目、对噪声的稳健性、图像大小不同时的实验表明,该方法能够比较正确、有效地估计图像中的端元数目,文中方法与其他端元数目估计算法及相关系数阈值的自动化确定问题还需要进一步研究。     

山东沿海浮游植物的同化系数

应用~(14)C示踪的方法,对山东沿海的13个海区浮游植物的同化系数进行了比较全面的测定和计算。指出不同海区和不同季节同化系数存在着明显的变化。提出不同海区季和年平均值的变化范围,以及垂直变化规律的特点。     

Numerical study on scale effect of form factor

The scale effect of form factor is investigated via a numerical approach in this paper, where the turbulent ship flow is computed by solving the steady and incompressible Reynolds-averaged Navier-Stokes and continuity equations. A wall function approach is employed to bridge the near-wall and outer turbulent flow region. The numerical scheme based on a finite-volume formulation is applied to discretize the coupled governing equation. For the sake of numerical stability, accuracy and economy, an identical grid is employed to compute ship flow at different Reynolds number, where the grid is optimized for the medium Reynolds number of the investigated range. Four surface ships and two sub-bodies with notably different geometrical characteristics are chosen as the investigated cases, where double-model flow without appendages is computed. The calculated total resistance coefficient shows a decreasing tendency against Reynolds number among all studied hulls. Similar to the calculated total resistance coefficient, the calculated friction resistance coefficient decreases with the Reynolds number and varies relatively little for a given Reynolds number among different hulls. The viscous pressure resistance coefficient is less insensitive to the Reynolds number but apparently depends on hull form. Compared with the form factor calculation based on empirical friction lines, the flat-plate friction prediction based on CFD approach clearly gives smaller Re-dependent form factor, which should more realistically reflect the scale effect of form factor. The form factor exhibits a near linear and increasing dependence on Reynolds number. The numerical results show that the dependence of r_P on Reynolds number mainly governs the scale effect of form factor.     

Characteristics of Parameters for Local Scour Depth around Submarine Pipelines in Waves

The purpose of this study is to investigate the characteristics of parameters for local scour depth around submarine pipes due to waves. Because it is impossible to consider all the factors that influence the scour, it is reasonable to investigate the correlations between parameters and scour. The experimental works about scour were performed for the conditions of 40, 60, 90 m pipe diameter, various wave periods, and wave height in the case of horizontal bed and 1/10 slope bed, respectively. Analyzing the results of experiments, the Reynolds number, Shields parameter, Keulegan-Carpenter number, Ursell number, and Modified Ursell number were estimated. The correlations between the relative scour depth, which is the maximum equilibrium local scour depth divided by the pipe diameter, and 5 parameters were analyzed. It was shown that there was hardly any correlation with the Reynolds number. In the case of a horizontal bed, the Keulegan-Carpent number had the highest correlation, but in the case of the slope bed the correlation was greatly reduced. The modified Ursell number showed a high correlation regardless of the type of bed.     

Outer wave number spectrum and statistical distribution of apparent wave number vector

Based on the ray theory and Longuet-Higgins’s linear model of sea waves, the joint distribution of wave envelope and apparent wave number vector is established. From the joint distribution, we define a new concept, namely the outer wave number spectrum, to describe the outer characteristics of ocean waves. The analytical form of the outer wave number spectrum, the probability distributions of the apparent wave number vector and its components are then derived. The outer wave number spectrum is compared with the inner wave number spectrum for the average status of wind-wave development corresponding to a peakness factor P = 3. Discussions on the similarity and difference between the outer wave number spectrum and inner one are also presented in the paper.     

大天鹅的越冬栖息地：荣成天鹅湖调查初报

荣成沿海港湾浅滩,自古以来就是大天鹅的越冬栖息地。主要栖地在马山港、八河港、朝阳港、雀门港,60年代初上万只,文革动乱,数量骤减,加强保护后回升,1989—1990年总数3250只。大天鹅迎着冰雪来,随着冰雪去。冬栖时间近4个月,多生活在海水中,但需要到淡水区饮水,主要食物是大叶藻(水生纤维植物)。初来时每个家族的数量多为4—6只,离去时多为2只,择偶使家族数增多,单个家族的成员个数减少了。迁飞时成大群活动。主要栖地马山港,水面4平方公里,三面陆地环抱,并有沙岗与大海隔开,仅有86米宽的流口相通。这里水净浪轻,大叶藻等水生植物资源丰富,岸边有成片的芦苇丛。这是荣成天鹅湖的主体,有大天鹅2000只。     

九龙江口鱼类浮游生物的生态

１９８７年３月到１９８８年２月在九龙江口的５个固定站位上，逐月进行鱼卵和仔，稚鱼调查的资料。结合１９８３年至１９８４年的鉴定资料进行分析，结果表明，该海区的鱼类生态结构系由淡水，半咸水，沿岸和海水鱼类等４种生态类型组成。鱼类主要产卵期为３－９月，盛期为５－８月。鱼卵数量以河口上游最多。种数则以河口下游较多。仔，稚鱼相对集中于河口中游，其数量和种数均为最多。在九龙江口放流，增殖或引进鱼类新种成功的机