共查询到18条相似文献，搜索用时 218 毫秒
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利用电子显微探针元素分析技术(EPMA)对黄海南部野生银鲳和鮸鱼的耳石进行了锶和钙沉积特征的初步分析。定量线分析结果表明,两种鱼类耳石的Sr/Ca之间存在显著的种间差异。银鲳耳石Sr/Ca比,在耳石核心及相邻处为低值区(5.86±0.92);3段Sr/Ca高值区分别为近核心部(7.88±1.28)、第1龄处(9.44±1.82)及耳石边缘(7.91±1.38);揭示银鲳孵化和早期发育应需要盐度适中的生境,当龄鱼在后期的生长中需洄游经过两段高盐生境(其中之一在第1龄时)。鮸鱼耳石Sr/Ca比波动表现为耳石核心处(7.72±0.97)高于其余部分,反映了鮸鱼孵化及初期发育阶段可能生活在高盐度生境,而当龄鱼随后阶段的生长和发育过程则会洄游至盐度有所降低的生境中进行。 相似文献
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为了解日本有明海沿岸六角川和筑后川河口水域鳀科鲚属鱼类刀鲚（Coilia nasus）的洄游特征和生境履历，利用电子探针微区分析（EPMA）技术，对采于两水域刀鲚的矢耳石进行了锶（Sr）元素含量的X射线强度面分布及耳石最长轴锶钙元素比值（Sr:Ca）的定量线分析。结果发现10尾六角川刀鲚（LJC）中的7尾以及15尾筑后川刀鲚（ZHC）耳石核心区域的Sr:Ca比值≤ 3，显示出这些个体在淡水生境出生并早期生活于淡水的履历。紧邻核心区域随后的生长阶段，Sr面分布图谱显示出了多样对应于含量水平差异的不同颜色同心环轮变化样式，Sr:Ca比值的波动亦可相应地分成1-6个差异极其显著的阶段，显示出这些个体在随后生活史阶段中极富变化的生境转换状况。另外3尾六角川刀鲚耳石核心的Sr:Ca比值较高（3-6.7），对应于半咸水生境；但在核心区域之外，Sr:Ca比值则高低变化不一，显示出这些六角川刀鲚个体在河口半咸水生境孵化的特征。本研究表明，二维Sr元素含量面分布图谱和基于耳石最长轴的Sr:Ca比值完全可以作为重建日本有明海沿岸各河口水域刀鲚生境履历的有效工具。 相似文献
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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... 相似文献
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对南海北部珠江口采集的滨珊瑚骨骼地球化学温度计指标B/Ca、Mg/Ca、Sr/Ca、U/Ca和δ18O进行了分析,目的在于测试这些地化指标在径流冲淡水影响下的稳定性.测试方法是将各个地化指标与水温对比并进行相关性分析.结果表明,Sr/Ca比值与当地水温有最好的相关性(r2=0.59),说明Sr/Ca是最稳定的温度计指标.而δ18O(r2=0.46)、B/Ca(r2=0.43)和U/Ca(r2=0.41)与水温的相关系数相对较低,说明这些指标除受到水温控制以外还受到其他环境因素的影响.在这些指标中,相关性最低的是Mg/Ca(r2=0.27),说明Mg/Ca受到除水温以外的因素影响最为显著,这就限制了Mg/Ca作为有效的温度计指标应用于古气候重建的研究. 相似文献
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促性腺激素释放激素（GnRH）在脊椎动物的繁殖过程中起着至关重要的作用,同时也存在于许多无脊椎动物中。利用cDNA末端快速扩增技术（RACE）克隆出曼氏无针乌贼（Sepiella japonica）促性腺激素释放激素（命名为SjGnRH,KP 982885.1）。SjGnRH基因的cDNA全长710 bp,开放阅读框（ORF）为273 bp,编码90个氨基酸,包括一条含有31个氨基酸的信号肽、12个氨基酸的GnRH多肽和44个氨基酸的GnRH相关肽（GAP）;SjGnRH与剑尖枪乌贼（Uroteuthis edulis）和真蛸（Octopus vulgaris）的同源性分别为86.7%和73.3%;SjGnRH高度保守的十二肽与剑尖枪乌贼和真蛸的octGnRH相似度达100%,其信号肽的相似性分别为66.7%和54.8%,GAP区的相似性分别为95.5%和77.3%;实时荧光定量PCR（qRT-PCR）结果显示,SjGnRH基因在成熟期的表达具有特异性,在脑中表达量最高,且与其他组织差异显著（P<0.05）;采用原位杂交技术检测SjGnRH mRNA在脑内的表达模式,结果表明：SjGnRH在食道上神经团、食道下神经团和视叶的不同部位均有表达,暗示SjGnRH可能参与曼氏无针乌贼的生殖调控作用。 相似文献
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梭鱼实验种群样本,系于1987年5月,从山东大沽河口搜集的亲鱼经人工授精后孵出的仔鱼在实验室培育取得;自然种群样本,于同年同地区采集。对于实验种群耳石生长轮形成的周期性进行了研究。结果表明,实验种群培育天数(D)与耳石生长轮数(N)之间的关系以回归式N=D-1.89表达之;根据实验种群耳石轮纹形成的周期性规律,鉴定了自然种群的日龄,表明二者具相似的周期性规律;协方差分析表明,梭鱼早期阶段的生长,自然种群比实验种群快。 相似文献
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南黄海表层沉积物碳酸盐及Ca、Sr、Ba分布特征 总被引：20，自引：2，他引：18
依据表层沉积物碳酸盐及元素Ca、Sr、Ba特征,探讨了南黄海表层沉积物的来源及其动力成因。现代黄河物质及老黄河三角洲物质以高钙、高碳酸盐和高Ca/Sr比值为特征;海区东北部物质以低钙、低碳酸盐、低Ca/Sr与Sr/Ba比值为特征,长江物质以碳酸盐及CaO含量、Ca/Sr与Sr/Ba比值中等为特征。表层沉积物碳酸盐、CaO含量及Ca/Sr、Sr/Ba比值的分布对不同特征沉积物的搬运和沉积具有很好的指示意义,南黄海北部Sr/Ba低值带沿NE－SW向延伸大体反映了黄海暖流的入侵路线。 相似文献
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不同孵化方式、培育密度和附着基对瘤背石磺人工繁育的影响 总被引：1，自引：0，他引：1
为提高瘤背石磺(Onchidium struma)在胚胎发育和幼虫发育过程中受精卵的孵化速率和幼虫的存活率, 本试验模拟滩涂生态环境对瘤背石磺亲贝进行人工养殖, 并促使其交配产卵。将采集的瘤背石磺新鲜卵块置于盐度18, 水温25～26 ℃的水体中进行孵化。比较3 种不同孵化方式对孵化速率的影响, 并研究不同孔径(1.0～1.5 mm)海绵附着基和不同培育密度对幼虫存活率的影响, 同时结合幼虫在各水层中分布的变化规律, 探索瘤背石磺胚胎发育和幼虫发育过程的关键技术。结果显示, 采用3 种方式(“喷淋”、“露空”和“梯笼”)孵化, 受精卵至出膜面盘幼虫期所需时间分别为8、6 和9 d; 大孔径(1.2～1.5 mm)海绵组对幼虫的附着效果较好, 存活率显著高于小孔径(1.0～1.2 mm)海绵组(P<0.05),且两者均显著高于未添加附着基组(P<0.05); 存活率与不同培育密度的二次多项式回归分析显示, 瘤背石磺幼虫培育密度为55～61 个/mL 时存活率较高。上述结果表明, “露空”孵化方式能显著缩短瘤背石磺孵化所需时间; 在生产过程中, 幼虫培育密度以55～61 个/mL 为宜, 面盘幼虫期投放大孔径海绵作为幼虫附着基能显著提高幼虫存活率且能明显缩短胚胎发育和幼虫发育所需时间。 相似文献
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通过对黔北石膏洞一石笋(编号SG-1)进行碳氧稳定同位素测试和XRF元素扫描分析,结果表明研究时段内Mg/Ca、Sr/Ca和Ba/Ca比值都表现了较明显的阶段性变化:Mg/Ca比值在9.9~6.6kaBP偏低,6.6~4.2kaBP期间逐渐升高,整体变化趋势与石笋δ18 O变化趋势较为一致,呈正相关关系,表明石膏洞石笋Mg/Ca比值主要受降水的影响,即降水增多(δ18 O偏负),岩溶水在母岩中滞留时间短,Mg/Ca比值降低;反之则升高。Sr/Ca和Ba/Ca比值在8.7~4.2kaBP的变化与石笋δ13 C变化趋势一致,呈反相关关系,植被和土壤微生物活动有可能是影响石膏洞石笋Sr/Ca和Ba/Ca的主要因素。但是在9.9~8.7kaBP,Sr/Ca和Ba/Ca比值与石笋δ13 C关系复杂,有可能同时受到温度、降水、地表植被和上覆土壤等众多因素的影响。因此,运用Ba/Ca和Sr/Ca进行古气候研究时需要慎重,要注重多指标对比研究。 相似文献
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Alan D. Wanamaker Jr Karl J. Kreutz Tiffany Wilson Harold W. Borns Jr Douglas S. Introne Scott Feindel 《Geo-Marine Letters》2008,28(5-6):359-368
To further evaluate the potential use of Mg/Ca and Sr/Ca ratios as a paleothermometer in the shell carbonate of the blue mussel Mytilus edulis, we grew juvenile mussels (～15 mm shell height; <2 years old) collected from Maine, USA, in controlled environments for 4 months. The four-by-three factorial design consisted of four circulating temperature baths (7, 11, 15 and 19°C), and three salinity ranges (23, 28, and 32). During the experiment, water Mg/Ca and Sr/Ca molar ratios were monitored weekly, and showed little variation across all salinity and temperature ranges. Data from sampled shells including all salinity treatments yielded relatively poor relationships between shell elemental chemistry and water temperatures. However, if only the low salinity treatment data (23) are used, the relationships between shell elemental chemistry and water temperature improve moderately. Based on the data presented here, it may be possible to use Mg/Ca and Sr/Ca ratios from the shell carbonate of juvenile M. edulis to reconstruct paleotemperatures in estuarine settings (salinity below 24) with a corresponding RMSE (root mean squared error; 95% confidence interval) of ±2.4°C and ±2.8°C, respectively. In order for this methodology to be statistically meaningful, water temperature changes must be rather large, as the errors associated with using Mg/Ca and Sr/Ca ratios from the shell material of M. edulis are substantial. Further work is required to determine if the findings presented here can be duplicated, and if the potential salinity effect is pervasive. 相似文献
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Fluctuations in lacustrine sedimentary environments significantly affect distributions of organic matter (OM), uranium, and other elements in shales. In this study a high-resolution geochemical record of fluctuations in the paleo-depositional environment of a terrestrial lake basin is provided on the basis of extensive samples collected from the Member 3 of the Paleogene Shahejie Formation (Es3) of the Niu-38 well in the Dongying Depression, Eastern China. These samples were tested for total organic carbon (TOC), element concentrations, and biomarkers to study the evolution and fluctuation in the depositional environments of an ancient lake basin and associated geochemical response. The evolution and fluctuation of the sedimentary environment from a deep lake to a semi-deep lake and then to a shallow lake delta were indicated by geochemical response. During this evolution, the values of TOC, S1, S2, Sr, and Ts/(Ts + Tm) remarkably decreased, whereas those of Co, Ni, Rb, Na, Fe/Mn, Fe/(Ca + Mg), and C29 mortane/C29 hopane significantly increased. The deep lake basin shows depositional fluctuations, as indicated by rock lithofacies and their geochemical parameters. A close interrelationship was observed among U concentration, TOC content, and inorganic element content. Uranium concentrations are positively correlated with TOC contents, Ca and Sr concentrations, and Sr/Ba and Ca/Mg ratios but negatively with K, Na, Ba, and Rb contents and Fe/(Ca + Mg) and Fe/Mn ratios. The observed increase in U concentration in the lower Es3 section is closely related to surface adsorption by clay minerals and OM, together with some replacements of Ca and Sr by U in the shales. 相似文献
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David Paul Gillikin Anne Lorrain Yves-Marie Paulet Luc André Frank Dehairs 《Geo-Marine Letters》2008,28(5-6):351-358
Barium/calcium profiles of bivalve shells are characterized by flat background signals periodically interrupted by sharp peaks, with the background signals correlated with water Ba/Ca. To test if the peaks are an environmental signal related to productivity, we analyzed high-resolution Ba/Ca profiles in bivalve shells that grew adjacent to one another. Two aragonitic Saxidomus giganteus show remarkable similarity over a decade of growth, clearly indicating an environmental forcing. Four calcitic Pecten maximus shells also record synchronous Ba/Ca peaks, again indicating an exogenous control. The Ba/Ca peaks, however, start ~40 days after the crash of a bloom, while sedimentation takes place immediately following the bloom. Barite formation in settling phytoplankton flocs, as has been previously proposed, is clearly not the cause of these peaks. Other possible causes, such as dissolved Ba in ambient water, spawning, shell organic matter content, and kinetic growth rate effects are also discussed, but none provide satisfactory explanations. Background shell Ba partition coefficients (Ba/Cacarbonate/Ba/Cawater) for both the calcitic shells (0.18) and aragonitic shells (0.16) are similar to that previously reported for the calcitic Mytilus edulis (~0.1). We suggest that Ba/Ca peaks in bivalve shells are caused by an as yet undetermined environmental forcing, while background Ba/Ca levels are a good indication of dissolved Ba/Ca in the water; both are independent of shell mineralogy. 相似文献
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形态学研究是海洋生物学的基础,对了解渔业资源的群体组成有重要意义。根据2018年7月至2019年6月在汕头—台湾浅滩渔场采获的940尾中国枪乌贼(Uroteuthis chinensis)的形态学数据,对其群体组成、胴长与体质量关系进行了研究;对各形态参数比进行了主成分分析;采用线性、指数、幂函数、Logistic4种函数对各形态学指标即右第一至第四腕长、右触腕长、鳍长和鳍宽与胴长的关系进行了拟合并选出最优方程。结果发现:中国枪乌贼的胴长范围为50.00～300.00 mm,平均胴长为111.44 mm,体质量范围为7.43～301.00 g,平均体质量为53.95 g,雌、雄生长系数b值分别为2.269 6和2.067 5,雌性比雄性生长速度更快,并存在个体小型化持续的趋势。主成分分析表明各形态参数比的差异可简化为2个主成分,第1主成分主要解释了各腕长、鳍宽的差异;第2主成分主要解释了鳍长的差异,因子荷载可视化雌雄在第2主成分具有明显偏离态势。各腕指标及鳍长、鳍宽与胴长关系以线性函数拟合最佳,协方差分析表明雌性与雄性个体之间存在显著差异(p0.05)。研究结果可为中国枪乌贼渔业生物学积累基础资料,加深对该资源种群组成及变动的了解,从而为实现资源的可持续利用和科学管理提供依据。 相似文献
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基于角质颚长度的头足类种类判别 总被引：6，自引：1，他引：5
本文根据2013 年8 月于舟山市沈家门东河菜场采集的5 种近海常见经济头足类(剑尖枪乌 贼、杜氏枪乌贼、金乌贼、曼氏无针乌贼和短蛸), 利用逐步判别和主成分分析法对其上、下角质颚 的各5 种长度指标(喙长、头盖长、脊突长、侧壁长、翼长)进行分析。结果显示, 这5 种头足类角质 颚长度差异显著(ANOVA: P<0.001), 其中以金乌贼的角质颚尺寸最大, 短蛸的角质颚尺寸最小。判 别分析显示, 角质颚长度适合用来划分头足类的种类, 综合判别成功率为96.2%, 其中以上颚侧壁 长、上颚头盖长和下颚脊突长对判定的贡献率最高。然而, 与之相比, 标准化后的角质颚长度则更适 合用来划分头足类的种类, 综合判别成功率达到100%, 其中以标准化下颚喙长和标准化下颚翼长对 判定的贡献率最高。主成分分析显示, 角质颚长度及标准化后角质颚长度对枪乌贼类和乌贼类的判 定成功率均达到100%.本文建立了一种基于角质颚长度判别分析法的头足类种类判定的新方法, 丰 富了头足类种类鉴定的技术手段, 为我国学者在相关领域的研究提供了基础。 相似文献
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长江口水域四种鱼类的耳石微化学研究 总被引：2，自引：0，他引：2
利用X-射线电子探针微区技术(electron probe microanalysis, EPMA),对长江口不同水域中捕获的焦氏舌鳎、皮氏叫姑鱼、鮸鱼和光泽黄颡鱼耳石中的Sr含量进行耳石微化学研究,结果发现,焦氏舌鳎是典型的海水鱼类,不仅Sr:Ca比(按惯例标准化为Sr:Ca×10~3)的移动平均值高(7),而且Sr含量面分析图亦呈现为对应高盐度海水的黄色或红色图谱。虽然皮氏叫姑鱼和鮸鱼从出生直至被捕Sr:Ca比的移动平均值都在3—7间波动,总体上属河口半咸水栖息鱼类,但从Sr含量面分析图来看,皮氏叫姑鱼生活史履历更为复杂,可包括淡水(对应蓝色图谱)和半咸水生境(对应绿色图谱);而鮸鱼仅在长江口较高盐度半咸水或海水生境中活动,未见进入过淡水的履历。光泽黄颡鱼表现出仅利用淡水生境的履历,其Sr:Ca比的移动平均值仅在1.5—3间窄幅波动,整个生活史均在淡水区域里活动,表现为长江口典型的淡水栖息鱼类。本研究从新的角度提供了较为客观、直观和最新的信息,用以较为准确地重建和掌握长江口这些不同鱼类的生境利用特征。 相似文献
17.
Swordtip squid (Uroteuthis edulis) is one of the important economical fishing target species in the East China Sea. Uroteuthis edulis is characterized by rapid growth, extensive migration, and long spawning period and sensitive to surrounding environment. In order to assess its stock status, it is necessary to explore its spawning season, growth patterns of different populations and their relationship with the environment in advance. In this paper, based on the samples of U. edulis collected in the East China Sea from September 2017 to March 2018, we explored the relationships between daily growth of statolith microstructure and environmental variables by gradient forest method and generalized additive model. The spawning season of U. edulis was found to be nearly one year, and two dominant season groups were found: the spring group with the peak period of April and the summer group with the peak period of August. Water temperature in the depth of 25 m (Temp_25), sea surface temperature (SST) and zonal velocity were the key environmental variables for the daily growth of April-spawning group. The most suitable environmental conditions for the growth of April-spawning group were water temperature (24?27°C) and velocity (0.1?0.3 m/s). SST, Temp_25 and mixed layer depth were the key environment variables for the daily growth of August-spawning group. The most suitable environmental conditions for the growth of August-spawning group were water temperature (21?28°C) and water depth (0?50 m). Key environmental variables of different groups suggested that early growth was significantly affected by seasonal changes of water temperature, current velocity and prey abundance. This study explored the relationships between early growth and environmental variables and provided the scientific guidance for the management and conservation of U. edulis. 相似文献
18.
The Es3L (lower sub-member of the third member of the Eocene Shahejie Formation) shale in the Jiyang Depression is a set of relatively thick and widely deposited lacustrine sediments with elevated organic carbon, and is considered to be one of the most important source rocks in East China. We can determine the mineralogy, organic and inorganic geochemistry of the Es3L shale and calculate paleoclimate indexes by using multiple geochemical proxies based on organic chemistry (total organic carbon [TOC] and Rock-Eval pyrolysis), major and trace elements, X-Ray diffraction, and carbon and oxygen isotope data from key wells alongside ECS (Elemental Capture Spectroscopy) well log data. These indicators can be used to analyze the evolution of the paleoenvironment and provide a mechanism of organic matter (OM) accumulation. The Es3L oil shale has high TOC abundance (most samples >3.0%) and is dominated by Type I kerogens. Additionally, the organic-rich shale is rich in CaO and enrichment in some trace metals is present, such as Sr, Ba and U. The positive δ13C and negative δ18O values, high Sr/Ba, B/Ga and Ca/Ca + Fe ratios and low C/S ratios indicate that the Es3L shales were mainly deposited in a semi-closed freshwater-brackish water lacustrine environment. The consistently low Ti/Al and Si/Al ratios reflect a restricted but rather homogeneous nature for the detrital supply. Many redox indicators, including the Th/U, V/(V + Ni), and δU ratios, pyrite morphology and TOC-TS-Fe diagrams suggest deposition under dysoxic to suboxic conditions. Subsequently, the brackish saline bottom water evolved into an anoxic water body under a relatively arid environment, during which organic-lean marls were deposited in the early stage. Later, an enhanced warm-humid climate provided an abundant mineral nutrient supply and promoted the accumulation of algal material. OM input from algal blooms reached a maximum during the deposition of the organic-rich calcareous shale with seasonal laminations. High P/Ti ratios and a strongly positive relationship between the P and TOC contents indicate that OM accumulation in the oil shale was mainly controlled by the high primary productivity of surface waters with help from a less stratified water column. Factors such as the physical protection of clay minerals and the dilution of detrital influx show less influence on OM enrichment. 相似文献