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以长江口、胶州湾、渤海湾和辽东湾4个地理群体的凤鲚(Coilia mystus)矢耳石样本为研究对象,采用形状指数和椭圆傅里叶系数分析相结合的方法研究了该4个凤鲚群体的矢耳石形态特征及差异性。方差分析结果表明,大部分形态变量存在显著的群体差异,引入协变量(耳石长)之后除形状因子外这种差异依然显著。基于协方差校正的判别分析只保留了耳石重量及9个傅里叶系数用于群体识别,而非参数检验的判别分析则保留了耳石重量、分形维数、环状度、矩形趋近率、圆度和19个傅里叶系数用于群体识别。相应地,基于非参检验的凤鲚群体的总体识别成功率(68.2%)明显高于协方差校正的判别分析结果(46.2%),表明前者比后者更能提高耳石形态分析的群体识别能力。 相似文献
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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。 相似文献
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Survival and reproductive rates in fish are often a function of body size. Consequently, spatial‐ and sex‐specific variation in somatic growth rates can have important consequences for population growth and resilience. We used otolith‐based approaches to estimate geographic‐ and sex‐specific growth rates of yellow‐eyed mullet (Aldrichetta forsteri) collected from 14 estuaries and harbours around New Zealand. Aldrichetta forsteri is an abundant and dominant component of New Zealand's estuarine fish fauna. We extracted otoliths from 511 fish, validated daily and annual increments, and prepared transverse thin sections of otoliths to determine age. “Size‐at‐age” relationships were estimated using both linear‐ and non‐linear (von Bertalanffy) growth models, and model performance was evaluated using Akaike's Information Criterion. Because growth rates of sampled fish were best approximated by linear functions, we used ANCOVA to test the null hypothesis that growth rates of A. forsteri were homogeneous between sexes and among geographic locations around New Zealand. Our analyses suggest heterogeneous growth rates between sexes and among locations. Interestingly, relative growth rates between sexes appeared to vary across separate latitudinal gradients for North Island and South Island. Within each island (but not across islands), female A. forsteri generally grew faster than males at the lowest latitudes; relative growth rates of females declined progressively below males with increasing latitude. 相似文献
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Spatial variability in phenotypic characteristics within a fish population may be used to infer the existence of multiple stocks, and knowledge of the population structure of exploited species is important for their sustainable management. In this study we investigated geographic variability in meristic (vertebral count) and morphometric (body shape) characteristics of sardine Sardinops sagax from three southern African regions: Namibia, the South African west coast, and the South African south coast. There were significant regional differences in vertebral counts, with Namibian fish tending to have more vertebrae than South African fish, but with no difference between sardine off the South African west and south coasts. Body shape was characterised using morphometric landmarks, and shape changes were investigated using geometric morphometrics, with influences on fish shape assessed using multivariate regressions. To remove the effects of allometry, the 22 shape variables (represented by Procrustes coordinates) were regressed against fish size (represented by centroid size). There was a significant allometric effect, which was removed by using the residuals of these regressions in further analyses. A multivariate multiple regression was applied to the 22 size-corrected shape variables and to three covariates: condition factor, stomach fullness and fat stage. The significant influence of these covariates was removed by using the residuals from this regression in a canonical variate analysis, where corrected shape variables were classified in relation to region, year and sex. The Mahalanobis distances from the canonical variate analysis differed significantly for most combinations of classifier variables, with clear separations among the three regions. Sardinops sagax off Namibia had thicker bodies and more contracted tail regions than South African fish, whereas S. sagax off the South African south coast had thinner bodies and smaller heads than those off the west coast. These results support the hypothesis of multiple sardine stocks around southern Africa. 相似文献
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Knowledge of stock structure is key for the effective management of any fish species. Amphidromous fish, which live and spawn in freshwater but spend a pelagic larval period at sea, have typically been assumed to disperse widely during their larval phase, resulting in populations being sourced from a single unstructured larval pool. We used otolith microchemical analysis to examine the stock structure of bluegill bully (Gobiomorphus hubbsi), a declining amphidromous eleotrid endemic to New Zealand, along the west coast of South Island, New Zealand. Some drainages – even those in close proximity (c. 20?km) – were readily distinguishable based on otolith trace element concentrations, while little structure was evident between other geographically disparate locations. These results indicate that, at least in some cases, locally retained larvae, rather than a single unstructured larval pool, dominates recruitment. Management of bluegill bully and other amphidromous species must therefore consider the possibility of regionally distinct populations. 相似文献
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Paul A. Hamer Gregory P. Jenkins Patrick Coutin 《Estuarine, Coastal and Shelf Science》2006,68(3-4):686
Chronological variation in otolith chemistry can be used to reconstruct migration histories of fish. The use of otolith chemistry to study migration, however, requires knowledge of relationships between the chemical properties of the water and elemental incorporation into otoliths, and how water chemistry varies in space and time. We explored the potential for otolith chemistry of snapper, Pagrus auratus, to provide information on movement history between a large semi-enclosed bay, Port Phillip, and coastal waters in south-eastern Australia. Comparisons of water chemistry across two years demonstrated that ambient barium (Ba) levels in Port Phillip Bay were approximately double those in coastal waters (11 μg L−1 versus 6 μg L−1). Ba levels in otolith margins of wild juvenile snapper were highly positively correlated with ambient levels across 17 sampling locations, and levels in otolith margins of adult snapper collected from Port Phillip Bay were approximately double those of snapper collected in coastal waters. Mean partition coefficients for Ba (DBa) were similar for juvenile (0.43) and adult (0.46) otoliths, suggesting that otolith Ba incorporation relative to ambient levels was similar across life-stages. Low Ba variation across otoliths from adult snapper maintained in tanks for three years indicated that annual temperature and/or growth cycles did not strongly influence otolith Ba variation. We concluded that chronological Ba variation in snapper otoliths would be a reliable proxy for life-history exposure to variable ambient Ba. We used water chemistry data and Ba levels across otoliths of ocean resident snapper to estimate otolith Ba levels indicative of residence in Port Phillip Bay (>10 μg g−1) or coastal waters (<6 μg g−1). Peaks in Ba exceeding 10 μg g−1 were common across otoliths of snapper collected in Port Phillip Bay and a nearby coastal region. The location of strong Ba peaks within otoliths was consistent with residence in Port Phillip Bay during the spring/summer when snapper move into the Bay from coastal waters to spawn. Our results for snapper support the use of otolith Ba as a proxy for ambient levels throughout the life-history, however, confident interpretation of migration history from otolith Ba chronologies will most likely require matching time series of ambient Ba in the water bodies of interest. 相似文献
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《African Journal of Marine Science》2013,35(2):137-144
Morphometric variation can be very useful for discriminating ‘phenotypic stocks’ as groups with similar life-history traits. Such groups are of great importance for accurate population-dynamics modelling for purposes of fishery stock assessment and management, independent of their genetic differences or similarities. This study is a contribution to the stock identification of the sardine Sardina pilchardus off the Moroccan Atlantic coast. The objectives were to (i) assess whether specimens from stocks defined by the FAO correspond to different morphotypes, and (ii) compare the obtained results with those recently published on the genetic variability of the studied populations. Morphometric analyses, using truss variables and landmarks data from sardine sampled from four widely spaced ports of landing along the Moroccan Atlantic coast (from north to south: Larache, Safi, Tantan and Dakhla), were carried out using multivariate and geometric approaches. Principal components analysis of truss variables and cluster analysis of the average shape of the sardine revealed the existence of three distinct morphotypes: ‘Larache,’ ‘Safi–Tantan’ and ‘Dakhla.’ These correspond well with the FAO’s stock subdivision. The morphometric variation might be related to the mesoscale hydrodynamic characteristics of the study area. However, these morphometric results do not fully accord with recently published data on genetic variability of the species. Those data indicated the genetic singularity of the Safi population, which could have led to the historical collapse of that sardine stock in the 1970s. Additional work is needed to validate the obtained results by taking into account seasonal variations and transitional areas between stocks. 相似文献
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Morphometric variation was used to study population structure of the cutlassfish Trichiurus lepturus on the Kenyan coast. In all, 16 morphometric measurements taken from 193 individuals from six sites were subjected to multivariate statistical analysis in order to determine possible stock differentiation. Multivariate analysis of variance indicated significant differences in the means of a combination of the morphometric characters among the sites, and discriminant function analysis by groups showed the presence of phenotypically distinct populations on the south and north coasts of Kenya. A classification tree analysis of morphometric characters validated the distinct groups and indicated certain characters to be useful for classifying specimens to source sites. The likely presence of distinct north and south stocks of T. lepturus on the Kenyan coast observed in our study will require validation by other methods, but indicates the potential need for spatially explicit models for managing fish populations on a large spatial scale. 相似文献
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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. 相似文献
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《African Journal of Marine Science》2013,35(2):119-124
Namibia’s most important commercial fisheries resource, the shallow-water Cape hake Merluccius capensis, is currently assessed using statistical catch-at-age analysis. Age data obtained from otoliths constitute an important data component of this model. Recent age-validation studies of M. capensis showed that growth was previously underestimated. We investigated this new fast-growth hypothesis (FGH) by using measurements and counts of translucent zones (T1 to T14, from otolith core to edge) on two survey otolith samples covering the entire range of fish lengths. We compared three hypotheses of periodicity of otolith zone formation and show that, if all zones are counted, T2 (at 9.0 mm otolith length), T5, T8, T11 and T14 are most likely to be annuli. A conversion from the slow-growth-hypothesis (SGH, currently used) age data was calculated as: FGH age group = round (0.41[SGH age group] + 0.25), and this formula should be applied to compute and test updated catch-at-age data in a future hake stock assessment. Additional adjustment for the hake stock assessment following the FGH, such as the timing of recruitment in winter and catches in summer, should be considered in future assessments. 相似文献
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北部湾金线鱼、深水金线鱼与日本金线鱼矢耳石形态识别的初步研究 总被引：2，自引：0，他引：2
采用2010年1～9月采自北部湾及邻近海域流刺网渔获的54尾金线鱼(Nemipterus virgatus( Houttuyn,1782))、71尾深水金线鱼(Nemi pterus bath ybius Snyder,1911)和65尾日本金线鱼(Nemi pterus ja ponicus (Bloch,1791))耳石样本,进行了椭圆傅立叶分析.耳石轮廓经图像处理后进行灰阶转换和二值化处理,消除噪点,然后解析为椭圆傅立叶标码( EFDs).采用77个EFD系数进行主成分分析和判别分析来区分3种金线鱼的耳石.结果表明,日本金线鱼幼鱼和成鱼耳石在性成熟前后存在显著的体长效应(P＜0.05),金线鱼和深水金线鱼则体长效应不显著(P＞0.05).因此在耳石椭圆傅立叶分析中,日本金线鱼采用性成熟个体样本,金线鱼和深水金线鱼采用全部样本.主成分分析中,第1、第2和第3主成分,分别解释了总变异的65.1％,15.3％和5.3％,可以将3种金线鱼耳石区分开来.EFD系数的逐步判别分析中,3种鱼的平均正判率达98.6％;交互验证结果显示,3种鱼的平均正判率达97.9％,这表明耳石椭圆傅立叶分析可以作为鱼种识别的有效工具. 相似文献
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The relationship between trace elements in chum salmon otoliths and in their rearing water was investigated to develop ways to distinguish chum salmon stocks in Korea. Rearing water and otoliths of hatchery-reared chum salmon fry were collected from three major hatcheries (Yangyang, Samchuk, and Uljin) on the east coast of Korea in spring 2001 and 2002. Trace elements in the otoliths and rearing water were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) at the Korea Basic Science Institute. The chemical composition of rearing water and otoliths of the salmon fry at specific sites did not vary significantly through the study period. The ratios of some trace elements to Ca in rearing water, such as Sr/Ca and Ba/Ca, was clearly reflected in the chemical composition of otoliths, although the absolute concentrations were different. These two elements may be useful in distinguishing between salmon hatcheries, which have different chemical environments. Discriminant analysis with the ratios of eight elements to Ca (Na/Ca, Mg/Ca, Al/Ca, Cu/Ca, Sr/Ca, Ba/ Ca, Mn/Ca, and Zn/Ca) revealed a distinct separation of natal area in stocks. The analysis of otolith chemistry may be an effective technique for identifying the origins of wild salmon caught at sea. 相似文献
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Rodrigo Wiff Andrés Flores Angel M. Segura Mauricio A. Barrientos Vilma Ojeda 《新西兰海洋与淡水研究杂志》2020,54(2):218-232
ABSTRACT Genypterus blacodes, in terms of its fishing history and local economic importance, is an emblematic species harvested in Chilean Patagonia (41°00’–57°00’S). Most of the current fisheries and biological knowledge of this species come from the open ocean, whereas information about the species in fjords and inner channels is fragmentary. In 2018, two research surveys targeting G. blacodes were conducted in the fjords and inner channels of Chilean Patagonia. A total of 253 pairs of sagittal otoliths were sampled at three different localities, and their contours were modelled using wavelet analysis as a tool for stock discrimination. Contours were compared using canonical analysis, and classification was performed using linear discriminant and Random Forest analyses. The results indicated that the wavelet method is efficient in modelling otolith contours, and the discriminant analyses showed differences among fishing grounds across the latitudinal gradient, thus confirming the hypothesis that G. blacodes conform to at least two separate stock units in Chilean Patagonia. Fishing grounds that were closer in space showed higher levels of misclassification. The discussion focuses on how environmental variables and the geography of fjords shape stock differences and how this information can be used for the sustainable management of G. blacodes. 相似文献
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Sukyung Kang Suam Kim Kevin Telmer David Welch Youn-Ho Lee 《Ocean Science Journal》2014,49(3):201-210
Chum salmon (Oncorhynchus keta) in the North Pacific Ocean are anadromous fish, and spend most of their life in the sea until spawning in natal streams. To identify the stock and habitat characteristics of chum salmon, the composition of chemical elements (Ca, Mn, Sr, Zn, and Ba) in otolith was examined using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Two main types of analytical work have been carried out; discrete spot analysis and line scan analysis of otolith sections. Salmon otoliths were obtained from the eastern (Canada and USA) and western (Japan and Korea) North Pacific during 1997–1999 spawning seasons. Spot analysis of otolith cores demonstrated significant differences in the element concentration among countries (p = 0.003). Line scanning from the core to the margin showed that Sr concentrations were elevated at the core of the otoliths, decreased during the freshwater stage, increased suddenly at a certain point, and oscillated periodically towards the margin matching with year-ring. The elevated Sr concentration at the core may reflect the maternal contribution to the egg, and the oscillations toward the margin may reflect salinity gradients between onshore/offshore or north/south migrations. The Zn profiles also oscillated and corresponded to the annual ring of the otolith. However, the profiles of Sr and Zn oscillated oppositely after salmon migrated to saline water and the Zn uptake declined toward the rim of the otolith while Sr uptake increased. 相似文献
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日本鳗鲡补充群体的日龄、全长、出生时间及耳石生长的变化 总被引：2，自引：0，他引：2
在中国大陆沿岸6个取样床搜集了日本鳗鲡白仔鳗,191尾用于长度测定,112尾鉴定了日龄及测定了耳石半径,近中心核的标记轮直径、耳石生长轮的宽度.补充群体长度平均值从(53.4±2.2)mm到(58.1±1.7)mm,长度与补充群体的地理分布之间无内在联系.补充群体日龄从(138.2±6.7)d至(155.2±9.0)d,长江口和温州地区补充群的日龄最低,以此为中心,向高纬度和低纬度走向分布,补充群的日龄都逐渐增大,补充群出生时间从1993年8月15日至1994年1月10日.低纬度的群体补充的时间早,其出生时间也早.纬度越高,补充的时间越迟,出生时间也晚.补充群耳石半径平均值从(142.5±8.4)μm至(155.8±14.5)μm,具有显着性差异(p<0.01).标记轮直径从(10.36±0.85)μm至(10.81±1.26)μm,其差异不具显著性(p>1.01).耳石生长轮平均宽度为(0.996-1.097) μm,其差异具有显著性(p<0.01),生长轮平均宽度以温州和长江口群体最大,以此为中心,向高纬度和低纬度分布的补充群的平均值分别逐渐减小.补充群耳石从中心至边缘生长轮宽度变化的共同点是在第90轮处平均宽度值最高. 相似文献
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Estuaries are regarded as valuable nursery habitats for many commercially important marine fishes, potentially providing a thermal resource, refuge from predators and a source of abundant prey. To assess the extent of estuarine use by juvenile (0+) common sole (Solea solea), whiting (Merlangius merlangus) and European seabass (Dicentrarchus labrax) we: (1) developed techniques to distinguish between estuarine and coastally-caught juveniles using otolith chemistry; and (2) examined the accuracy with which multi-elemental signatures could re-classify juveniles to their region of collection.High-resolution solution-based inductively coupled plasma mass spectrometry (HB-SB-ICPMS) was used to quantify 32 elements within the juvenile otoliths; 14 elements occurred above detection limits for all samples. Some elemental distributions demonstrated clear differences between estuarine and coastally-caught fish. Multivariate analysis of the otolith chemistry data resulted in 95–100% re-classification accuracy to the region of collection. Estuarine and coastal signatures were most clearly defined for sole which, compared to bass and whiting, have low mobility and are less likely to move from estuarine to coastal habitats between larval settlement and later migration to adult stocks. Sole were the only species to reveal an energetic benefit associated with an estuarine juvenile phase. The physiological ability of bass to access upper estuarine regions was consistent with some elemental data, while the high mobility and restricted range of whiting resulted in less distinct otolith chemistries. 相似文献
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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。 相似文献