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The otolith morphology of two croaker species(C ollichthys lucidus and C ollichthys niveatus) from three areas(Liaodong Bay, LD; Huanghe(Yellow) River estuary, HRE; Jiaozhou Bay, JZ) along the northern Chinese coast were investigated for species identifi cation and stock discrimination. The otolith contour shape described by elliptic Fourier coefficients(EFC) were analysed using principal components analysis(PCA) and stepwise canonical discriminant analysis(CDA) to identify species and stocks. The two species were well dif ferentiated, with an overall classifi cation success rate of 97.8%. And variations in the otolith shapes were significant enough to discriminate among the three geographical samples of C. lucidus(67.7%) or C. niveatus(65.2%). Relatively high mis-assignment occurred between the geographically adjacent LD and HRE samples, which implied that individual mixing may exist between the two samples. This study yielded information complementary to that derived from genetic studies and provided information for assessing the stock structure of C. lucidus and C. niveatus in the Bohai Sea and the Yellow Sea. 相似文献
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Spatial and Seasonal Patterns of Ichthyoplankton Assemblages in the Haizhou Bay and Its Adjacent Waters of China 总被引：1，自引：0，他引：1
《中国海洋大学学报(英文版)》2015,(6)
Surveys were conducted in five voyages in Haizhou Bay and its adjacent coastal area from March to December 2011 during full moon spring tides. The ichthyoplankton assemblages and the environmental factors that affect their spatial and seasonal patterns were determined. Totally 35 and 12 fish egg and larvae taxa were identified, respectively. Over the past several decades, the egg and larval species composition has significantly changed in Haizhou Bay and its adjacent waters, most likely corresponding with the alteration of fishery resources, which are strongly affected by anthropogenic activities and climate change. The Bray-Curtis dissimilarity index identified four assemblages: near-shore bay assemblage, middle bay assemblage and two closely related assemblages(near-shore/middle bay assemblage and middle/edge of bay assemblage). The primary species of each assemblage principally reflected the spawning strategies of adult fish. The near-shore bay assemblage generally occurred in near-shore bay, with depths measuring 20 m, and the middle bay assemblage generally occurred in the middle of bay, with depths measuring 20 to 40 m. Spatial and seasonal variations in ichthyoplankton in each assemblage were determined by interactions between biological behavioral traits and oceanographic features, particularly the variation of local conditions within the constraint of a general reproductive strategy. The results of Spearman's rank correlation analysis indicated that both fish egg and larval abundance were positively correlated with depth, which is critical to the oceanographic features in Haizhou Bay. 相似文献
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Chinese sturgeon (Acipenser sinensis) is the flagship species of the Changjiang River. The migration route of this species is blocked by the first dam, the Gezhou Dam, and its reproduction is affected by the Three Gorges Dam (TGD), one of the largest dams in the world. We studied the impact of the impoundment of the Three Gorges Reservoir (TGR) since 2003 on the spawning stock and the natural reproduction of the Chinese sturgeon by using our monitoring data from 1997 to 2013. Results indicate that TGR impoundment has delayed the first spawning dates of the fish from middle-late October to late November, decreased the amount of spawning activities from twice to only once each year, and significantly reduced egg production. In particular, the fish did not demonstrate any spawning activities in 2013. Therefore, TGR impoundment significantly affects the natural reproduction of the fish downstream of the TGD. The spawning stock size of the fish is also predicted to further decrease in the future, which will lead to a risk of population extinction. Ecological regulations must be imposed on decreasing the water temperature to 20°C before mid-October and increasing water discharge downstream of the TGD in October to induce spawning of the Chinese sturgeon. 相似文献
5.
Stock discrimination of spottedtail goby (Synechogobius ommaturus) in the Yellow Sea by analysis of otolith shape 总被引：1，自引：0，他引：1
Otolith shape is species specific and is an ideal marker of fish population affiliation. In this study, otolith shape of spottedtail goby Synechogobius ommaturus is used to identify stocks in different spawning locations in the Yellow Sea. The main objectives of this study are to explore the potential existence of local stocks of spottedtail goby in the Yellow Sea by analysis of otolith shape, and to investigate ambient impacts on otolith shape. Spottedtail goby was sampled in five locations in the Yellow Sea in 2007 and 2008. Otoliths are described using variables correlated to size (otolith area, perimeter, length, width, and weight) and shape (rectangularity, circularity, and 20 Fourier harmonics). Only standardized otolith variables are used so that the effect of otolith size on the shape variables could be eliminated. There is no significant difference among variables of sex, year, and side (left and right). However, the otolith shapes of the spring stocks and the autumn stocks differ significantly. Otolith shape differences are greater among locations than between years. Correct classification rate of spottedtail goby with the otolith shape at different sampling locations range from 29.7%–77.4%. 相似文献
6.
LIU Chunlin ZHANG Chi TIAN Yongjun WANG Liangming LIN Longshan LI Yuan WATANABE Yoshiro 《中国海洋大学学报(英文版)》2022,21(1):236-242
After decades of low year classes,the stock of Japanese sardine(Sardinops melanostictus)has begun to recover since the mid-2000s.The hatch dates and otolith growth rates of age-0 juvenile sardine,which were collected in the subarctic Oyashio waters in autumn 2018,were determined from an otolith microstructure analysis.The sardines were hatched from late January to late April,while mostly in February and March.The otolith growth rate increased continuously up to 60 d after hatching and thereafter de-creased.The revealed growth rate in a crucial growth period is faster than that reported for juvenile sardines collected in the 1990s,which is coincided with the recent recovery trend of the sardine stock.Two groups with different hatch dates,growth histories,and migration routes were identified using unsupervised random forest clustering analysis.They were considered inshore and offshore migration individuals in accordance with recent researches.In the offshore group,a high proportion of sardine juveniles hatched late and grew faster in the Kuroshio-Oyashio transitional waters,a finding consistent with the hypothesis of growth-rate-dependent re-cruitment.This finding on the population composition and growth rate of juvenile sardine in the Oyashio waters can be a basis for an improved prediction of their survival and provides us with valuable information on the recruitment processes of this stock during the period of stock recovery. 相似文献
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This paper deals with population identification ofParargyrops edita Tanaka. Samples of spawning stocks were collected from Niushan-Penghu, Minnan-Taiwan shoal (Southern Fujian-Taiwan shoal)
and Beibu Gulf during the spawning period 1981–1982. Morphological characters, both meristic and morphometric, are counted
and measured respectively. The stock concept and intraspecific categories have been discussed. Some meristic characters as
the number of left or right ventral fin spine, right ventral fin rays and abdominal vertebrae of this fish may be constant,
others as the numbers of left or right pectoral fin rays and gill-rakers may have obvious geographical variation. Morphological
characters have not attained the level of subspecific distinctness, no sub-species could be found among these stocks by means
of coefficient of difference (C.D.). Basing upon the comparative analysis ofM
diff, the authors consider that stocks of Minnan-Taiwan shoal and Niushan-Penghu belong to the same local population, Taiwan Strait
local population. By means of the discriminant function analysis and linear relationship analysis, statistical differences
will be found to exist in meristic characters between the stock of Minnan-Taiwan shoal and that of Niushan-Penghu, so that
the two are virtually different stocks or subpopulations. The stock of Beibu Gulf belongs to another called the Beibu Gulf
local population. These two local populations are of allopatric distribution and show statistically significant difference
between themselves. Among these stocks, the Minnan-Taiwan shoal stock is strongly influenced by the much more complicated
environmental conditions of the mixed boundary region of the subtropical Sino-Japanese Subregion in the north and the tropical
Indo-Malayan Subregion in the south. Thus its coefficient of variability (C.V.) is greater than those of the other two in
the mean values of various meristic characters.
This paper was published in Chinese inOceanologia et Limnologia Sinica
14 (6): 511–520. 相似文献
9.
Otolith morphology is widely used for fish stock identification.The sulcus,a structure on the medial side of the otolith,is an important feature in morphological analysis.This study was conducted to evaluate the feasibility of using sulcus morphology for stock identification and to compare its performance with commonly used otolith morphology analysis.Otoliths were collected and analyzed from three geographical groups(the Huanghe(Yellow)River estuary,HHE;the Jiaozhou Bay,JZB;and the Changjiang(Yangtze)River estuary,CJE)of yellow drum Nibea albiftora.The results show that the analysis of sulcus morphology based on shape indices(SIs),elliptic Fourier coefficients(EFc),and a combination of the two parameters identified stocks at overall classification rates of 51.0%,72.5%,and 73.2%,respectively.These classification rates are similar to those obtained using otolith morphology analysis(57.0%,73.8%,and76.5%by SIs,EFc,and their combination,respectively).The findings suggest that sulcus morphology is comparable to the commonly used otolith morphology for identifying stocks of sciaenids,such as the yellow drum.For both otolith and sulcus morphology,EFc could identify the stocks more efficiently than SIs,while the combination of SIs and EFc was even better. 相似文献
10.
Yan Taiming Hu Jiaxiang Cai Yueping Xiong Sen Yang Shiyong Wang Xiongyan He Zhi 《中国海洋湖沼学报》2017,35(5):1197-1204
Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths.Otolith development was observed and their formation period was verifi ed by monitoring larvae and juveniles of knownage.The results revealed that lapilli and sagittae developed before hatching,and the first otolith increment was identified at 2 days post hatching in both.The shape of lapilli was relatively stable during development compared with that of sagittae;however,growth of four sagittae and lapilli areas was consistent,but the posterior area grew faster than the anterior area and the ventral surface grew faster than the dorsal surface.Similarly,the sum length of the radius of the anterior and posterior areas on sagittae and lapilli were linearly and binomially related to total fish length,respectively.Moreover,daily deposition rates were validated by monitoring knownage larvae and juveniles.The increase in lapilli width was 1.88±0.080 0μm at the ninth increment,which reached a maximum and the decreased gradually toward the otolith edge,whereas that of sagittae increased more slowly.These results illustrate the developmental biology of S.davidi,which will aid in population conservation and fish stock management. 相似文献
11.
In this paper, the morphological characters of eggs and larvae ofSardinella aurita (Cuvier & Valenciennes), its spawning ground, spawning seasons and spawning conditions have been studied.
Sardinella aurita likes to breed in the upwelling area and selects the Waixie fishing ground as its main spawning ground. The months from February
to September are its spawning seasons, reaching its peak in April. In the main spawning ground, the temperature of the surface
layer was found to be 24.4–25.2°C, the salinity 33.87–34.07%. and the depth of water between 34–60m.
The distribution of the larvae is closely related to the distribution of plankton, the path of migration of adult fish, and
the current direction of the water system.
In order to protect fishery resources, it is necessary to prohibit catching the spawning fish in the Waixie fishing ground
in April, and the catching of immatures from March to June.
This paper was published in Chinese inOcean. Limn. Sinica
14(3): 240–248, 1983. 相似文献
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2005年5月~8月在雷州市覃斗镇海威水产种苗基地的室内水池进行方斑东风螺亲螺培育,对亲螺不同批次产出的卵囊、卵、及其幼虫进行比较。结果表明:随着亲螺产卵批次的增加,亲螺产卵囊数、卵囊含卵数、产卵量逐次减少;卵囊长、宽逐次变小,厚逐次增加,形状由葵花子片状的比例大变为棒状的比例大;幼虫浮游期逐次延长;变态期幼虫壳长逐次变小;各批次之间的变态率逐次降低;卵径、孵化率、出囊幼虫大小差异不显著。 相似文献
13.
Use of Otolith Shape for the Identification of Trumpeter Sillago （Sillago maculata） and Silver Sillago （Sillago sihama） 总被引：1，自引：0，他引：1
Otolith shape is species-specific in fish. In this study, 161 samples of Trumpeter sillago Sillago maculata and 164 of Silver sillago Sillago sihama were collected from Beibu Gulf in July 2009. The main objective of this study was to use morphological variables and Fourier harmonics to describe otolith characteristics and use discriminant analyses to separate the two species. Otoliths were measured by traditional one and two dimensional measures(otolith length, width, diameters, area, perimeter, rectangularity and circularity), as well as by Fourier analysis to capture the finer regions of the otolith. Analysis of covariance(ANCOVA)showed that there was significant correlation between morphological variables(diameter, perimeter, otolith length, otolith width, otolith area, density, harmonics 3, harmonics 4, harmonics 5, harmonics 13, harmonics 15, and harmonics 16)and body length. To minimize size effects on the morphological variables between species, only fish with a body length between 90 and 140 mm were included in the data analysis and the variables which had significant relation with body length were transformed using the residual. The result showed that the accuracy of discriminant analysis was 97. 8% and 100% for Trumpeter sillago and Silver sillago, respectively. This high accuracy indicated that otolith shape was described accurately by morphological variables and Fourier harmonics, and discriminant analysis was an effective way to identify and separate the two species. 相似文献
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In order to improve production and breed new broods of bay scallopArgopecten irradians irradians, different-colored orange, purple and white lines were established by two mating methods of self-fertilization and mass spawning
at a commercial scallop hatchery in spring, 2002. And then larval growth and survival of different lines was compared to test
whether there is a relationship between shell color and growth and survival at early developmental stage. Both growth and
survival have no significant differences among different experimental larvae of self-fertilization or mass spawning. Results
are as following in the order of orange, purple and white shell stock. For the self-fertilization, growth rates of larvae
were 6.174, 6.412, and 6.599 μm/d, respectively. Survival rates of larvae at Day 3 were 74.41%, 76.86%, and 82.05%; Day 6
were 49.14%, 65.63%, and 52.79%; and Day 9 were 25.06%, 20.80%, and 26.47%, respectively. For the mass spawning, the growth
rates were 7.836, 7.941, and 7.878 μm/d, respectively. Survival rates at Day 3 were 93.05%, 91.95%, and 92.50%; Day 6 were
79.17%, 78.05%, and 82.50%; and Day 9 were 34.72%, 36.67%, and 38.33%, respectively. The absence of any relationship between
shell color and growth and survival at the larval stage may be resulted from their common genetic basis.
This work was financially supported by Project of Scientific Innovation, Chinese Academy of Sciences (ZKCX2-211). 相似文献
15.
Spatio-seasonal patterns of fish diversity,Haizhou Bay,China 总被引：3，自引：0，他引：3
Spatial-seasonal patterns in fish diversity in Haizhou Bay were studied based on stratified random surveys conducted in 2011.Principal component analysis was conducted to distinguish different diversity components,and the relationships among 11 diversity indices were explored.Generalized additive models were constructed to examine the environmental effects on diversity indices.Eleven diversity indices were grouped into four components:(1) species numbers and richness,(2) heterogeneous indices,(3) evenness,and(4) taxonomic relatedness.The results show that diversity indices among different components are complementary.Spatial patterns show that fish diversity was higher in coastal areas,which was affected by complex bottom topography and spatial variations of water mass and currents.Seasonal trends could be best explained by the seasonal migration of dominant fish species.Fish diversity generally declined with increasing depth except for taxonomic distinctness,which increased with latitude.In addition,bottom temperature had a significant effect on diversity index of richness.These results indicate that substrate complexity and environmental gradients had important influences on fish diversity patterns,and these factors should be considered in fishery resource management and conservation.Furthermore,diversity in two functional groups(demersal/pelagic fishes) was influenced by different environmental factors.Therefore,the distribution of individual species or new indicators in diversity should be applied to examine spatio-seasonal variations in fish diversity. 相似文献
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根据 1997年 12月至 1999年 6月在南海北部陆架区海域进行的底拖网渔业资源调查的资料 ,统计分析了南海北部陆架区海域深水金线鱼性腺成熟期的组成及分布、季节性变化和水深变化规律。结果表明 ,南海北部陆架区海域深水金线鱼的产卵场位于广东沿海水深 6 0～ 15 0m海区 ,尤其是珠江口外海区的群体更为密集 ;该生殖群体的产卵期较长 ,且分布范围大 ,未见有显著性变化。 相似文献
17.
The spatial distribution of siliceous microfossils (diatoms and silicoflagellates) in the surface sediments was mapped at 113 sites in the Yellow Sea and sea areas adjacent to the Changjiang (Yangtze) River, China. In total, 267 diatom taxa and two silicoflagellate species were identified from the sediments. The spatial variations in abundance and diversity were classified into three distinct geographic patterns using Q mode clustering: a south-north geographic pattern, a coastal-offshore pattern and a unique pattern in the Changjiang River mouth. The south-north geographic pattern was related to the spatial variations in sea temperature. Coscinodiscus oculatus, a warm-water species, indicated these variations by a gradual decrease in abundance from the south to the north. The coastal-offshore pattern was in response to the spatial variations in salinity. Cyclotella stylorum, Actinocyclus ehrenbergii and Dictyocha messanensis, the dominant brackish species in coastal waters, significantly decreased at the isobaths of approximately 30 m, where the salinity was higher than 31. Paralia sulcata and Podosira stelliger indicated the impact of the Yellow Sea Warm Current in the central Yellow Sea. The unique pattern in the Changjiang River mouth showed the highest species diversity but lower abundance, apparently because: freshwater input can significantly increase the proportion of brackish species; nutrients can supply the growth of phytoplankton; and high sedimentation rates can dilute the microfossil abundance in the sediments. Our results show that an integration of environmental factors (e.g., nutrient levels, sedimentation rate, sea temperature, salinity and water depth) determined the spatial characteristics of the siliceous microfossils in the surface sediments. 相似文献
18.
北部湾二长棘鲷生长、死亡及其群体组成 总被引：6，自引：1，他引：5
利用2006年7月至2008年3月北部湾渔业商业捕捞底拖网和刺网渔获物中采集的样本,对北部湾二长棘鲷的生长、死亡及其群体组成进行了初步研究。结果表明,北部湾二长棘鲷优势体长70～140 mm,占82.2%;优势体重为20～60 g,占54.29%;ARSS分析表明雌雄生长不存在显著性差异(P>0.05),繁殖期性比为1.21∶1;von Bertalanffy生长方程的主要参数分别为:L∞=292.8 mm,K=0.167,t0=-1.116;体重的生长拐点为5.463龄;总死亡系数、自然死亡系数和捕捞死亡系数分别为1.041 4、0.282 8和0.752 6,当前开发率为0.728。 相似文献
19.
ForoodAZARIDEHKORDI NobukazuNAKAGOSHI 《中国地理科学(英文版)》2004,14(4):350-354
Japan ranks fifth in the world for the number of large dams. Environmental impacts of large dams are known, such as enormous losses of water or disruption of fish spawning, however, impacts of the dams on their up streams are functions of topography of the up stream. Haizuka Dam is located in Hiroshima Prefecture, Japan and its implementation will start in 2006. This large dam influences its up stream through dam making activities, which occurs in order and with different spatial presences that were categorized into chronological and spatial impacts. In this case study, spatial impacts were further divided into horizontal and vertical ones. The horizontal impacts were identified as new roads, diversion tunnel, dam lake, and submerged cultivated land, while vertical impacts were recognized as submerged historical monuments, slope protections, dam body, and deforested area in the reservoir. There were convergences of spatial and temporal impacts, however, the extent of the impacts was limited to the lake boundary. 相似文献
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本文以厦门市为例,基于MODIS影像反演的大气气溶胶光学厚度（AOD）,利用空间自相关和景观格局指数从数量、形态和结构方面综合分析了2014年各月份（5月和9月除外）AOD时空格局变化。结果表明,研究区AOD具有明显的时空分布差异,林地上空的AOD处于较低等级,建设用地上空AOD大部分处于中高等级;AOD在春夏季较大,在秋冬季较小。AOD分布存在显著正空间自相关性,而且主要存在高高（HH）、低低（LL）、高低（HL）3种聚集模式。低低聚集模式主要分布在厦门市的北部山区;高高（HH）和高低（HL）模式主要分布在本岛东北部新城和本岛外各新城的城区。在景观格局指数方面,从秋冬季节到春夏季节期间,研究区气溶胶光学厚度高等级斑块增加,景观结构趋于复杂,景观异质性增加。对AOD时空格局变化进行多指标综合分析可以更加深入、细致、全面地刻画气溶胶的变化规律,有助于精确评估气溶胶对环境、气候等的影响,为城市可持续发展提供决策支持。 相似文献