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1.
The geographic al variations in life history characteristic s of small yellow cro aker Larimich thys polyactis,caused by experienced different environmental conditions,have been observed in China seas.Previous studies based on spatial distribution,migration route,and body morphometrics suggested a complex stock structure.In this study,to clarify the source of a spawning stock,we investigated the reproduction strategy and inter-structure of the Haizhou Bay(HZB)spawning stock in the middle Yellow Sea from both egg survey and adult otolith increment analysis.Egg and adult samples were collected from three surveys during spawning season in 2013.Distinct spatial and temporal variations were detected in egg distribution and size,and otolith shape analy sis of adult fishes revealed two morphotypes with different increment growth using random forest cluster.The results indicate the existence of two components within the same spawning stock in HZB from different wintering grounds,and accordingly special protection should be required for this stock given the significance to maintain connectivity between adj acent subpopulations. 相似文献
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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
3.
The status of fishery stocks in the coastal waters of China is far from ideal, mainly due to climate change and the impacts
of human activities (e.g., pollution and overfishing). Thus, the restoration and protection of fishery resources have become
critical and complex. The stability and balanced structure of the fish community is a basic foundation for the protection
of fishery resources. Based on data collected from bottom trawls by the R/V Beidou in continental shelf of the East China Sea in November 2006 and February 2007, changes in the composition and diversity of
fish species and functional groups were analyzed. The research area was divided into offshore waters and inshore waters by
the two-way indicator species analysis (TWIA). The results showed that the dominant species were different between offshore
waters and inshore waters and also varied with the survey time. The most abundant family was Sciaenidae and Teraponidae in
November 2006, Sciaenidae, Engraulidae and Triglidae were most abundant in February 2007. The species belonged mainly to mobile
piscivores (G6), benthivores/piscivores (G4), benthivores (G3) and planktivores (G1), and the dominant species in November
2006 were commercial species (e.g. Larimichthys polyactis and Trichiurus japonicus), but small-sized species were dominant in February 2007 (e.g., Harpadon nehereus, Benthosema pterotum, Champsodon capensis, and Acropoma japonicum). The species diversity showed a similar trend as the functional group diversity. Stations with higher diversity were mainly
distributed in inshore waters in February 2007, whereas higher diversity was found in offshore waters in November 2006. The
highest biomass and species number were found in G6 group, followed by the G4, G5 and G1 groups. The distribution of the number
of individuals of each functional group showed the opposite trend as that of the biomass distribution. In addition, the size
spectra were mainly concentrated around 3–29 cm, and the individual number of fish species gradually decreased with the increase
in body size, but the relative biomass showed a moderate fluctuation in each size class. These changes showed that species
with faster growth rate and earlier maturity age became dominant in continental shelf of the East China Sea. So the variations
in biological characteristics of fish should be fully considered in maintaining sustainable utilization of fishery resource. 相似文献
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以综合催熟措施和移植精荚手术相结合的技术方法,解决了鱼塭产斑节对虾催熟效应期长,产卵率低,易蜕壳失去精荚等难题。使用 ２７８ 尾雌虾,催熟率达９０％ 以上,在４０ ｄ 内共产卵６０８ 尾次,卵量１８ ５３０ 万粒,孵出无节幼体１１ ９９８ 万尾,平均孵化率 ６４．７％ ,平均每尾雌虾孵出无节幼体 ４３．１ 万尾,育成商品虾苗 １ ０２８．５ 万尾,育苗平均成活率 １３．６％ ,试养成活率５７．１％ 相似文献
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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
8.
波纹龙虾胚胎的离体培养及发育观察 总被引：1，自引：1，他引：0
对波纹龙虾不同发育时期的胚胎进行离体培养和显微观察。结果表明,初始培育的离体胚胎愈接近孵化期,其孵化率愈高(最高达80.0%);波纹龙虾胚胎发育经历受精卵、卵裂期、囊胚期、原肠期、中眼色素形成期、复眼色素形成期、心跳期、破膜前期和出膜期;胚胎在发育过程中颜色变化:橙红→深橙红→砖红→灰白→接近透明。 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.
Distribution of microbial populations and their relationship with environmental variables in the North Yellow Sea, China 总被引：1，自引：0，他引：1
Xiaoge Bai Min Wang Yantao Liang Zhifeng Zhang Fang Wang Xuejiao Jiang 《中国海洋大学学报(英文版)》2012,11(1):75-85
In order to understand the large-scale spatial distribution characteristics of picoplankton,nanophytoplankton and virio-plankton and their relationship with environmental variables in coastal and offshore waters,flow cytometry(FCM) was used to ana-lyze microbial abundance of samples collected in summer from four depths at 36 stations in the North Yellow Sea(NYS).The data revealed spatial heterogeneity in microbial populations in the offshore and near-shore waters of the NYS during the summer.For the surface layer,picoeukaryotes were abundant in the near-shore waters,Synechococcus was abundant in the offshore areas,and bacte-rial and viral abundances were high in the near-shore waters around the Liaodong peninsula.In the near-shore waters,no significant vertical variation of picophytoplankton(0.2-2μm) abundance was found.However,the nanophytoplankton abundance was higher in the upper layers(from the surface to 10 m depth) than in the bottom layer.For the offshore waters,both pico-and nanophytoplankton(2-20μm) abundance decreased sharply with depth in the North Yellow Sea Cold Water Mass(NYSCWM).But,for the vertical dis-tribution of virus and bacteria abundance,no significant variation was observed in both near-shore and offshore waters.Autotrophic microbes were more sensitive to environmental change than heterotrophic microbes and viruses.Viruses showed a positive correla-tion with bacterial abundance,suggesting that the bacteriophage might be prominent for virioplankton(about 0.45μm) in summer in the NYS and that viral abundance might play an important role in microbial loop functions. 相似文献
11.
We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias, and Acanthogobius hasta) found in northern Chinese coastal waters. The five species were well differentiated with high overall classification success using shape indices(83.7%), elliptic Fourier coefficients(98.6%), or the combination of both methods(94.9%). However, shape analysis alone was only moderately successful at discriminating among the four stocks(Liaodong Bay, LD; Bohai Bay, BH; Huanghe(Yellow) River estuary HRE, and Jiaozhou Bay, JZ stocks) of A. hasta(50%–54%) and C. stigmatias(65.7%–75.8%). For these two species, shape analysis was moderately successful at discriminating the HRE or JZ stocks from other stocks, but failed to effectively identify the LD and BH stocks. A large number of otoliths were misclassified between the HRE and JZ stocks, which are geographically well separated. The classification success for stock discrimination was higher using elliptic Fourier coefficients alone(70.2%) or in combination with shape indices(75.8%) than using only shape indices(65.7%) in C. stigmatias whereas there was little difference among the three methods for A. hasta. Our results supported the common belief that otolith shape analysis is generally more effective for interspecific identification than intraspecific discrimination. Moreover, compared with shape indices analysis, Fourier analysis improves classification success during inter- and intra-species discrimination by otolith shape analysis, although this did not necessarily always occur in all fish species. 相似文献
12.
线纹尖塘鳢的胚后发育大致分为仔鱼、稚鱼、幼鱼和成鱼期。初孵仔鱼仅2.875mm。前期仔鱼混合营养期短,仅2～3d。后期仔鱼为器官发育、奇鳍条基本形成期,历时10d,平均全长从4.31mm增至8.97mm。稚鱼为器官分化完毕,奇偶鳍条分节、鳞被形成期,历时27～29d,长至平均全长27.79mm。早期幼鱼鳞被等发育完善,进入生长时期。仔鱼开口饵料为150～200μm轮虫,其摄饵大小与口宽呈正相关。15mm后稚鱼可驯饵摄食人工混合料。对仔、稚、幼鱼的生长测定结果显示,全长与日龄呈线性关系L=0.5289t-0.7354(r2=0.9720),体重与日龄呈指数函数关系,W=0.8236e0.1267t(r2=0.9611),全长与体重呈幂函数关系,曲线回归方程W=0.0045L3.2527,b=3.2527,属匀速生长型。采用池塘培水,添加外源饵料生物系列,稚鱼全长15mm时开始驯饵。2002-2005年共培育全长2.2～3.4cm早期幼鱼523.7万尾,仔鱼培育成15mm稚鱼的成活率为26.8%,培育成早期幼鱼的成活率为75.7%。 相似文献
13.
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
14.
INTRODUCTIONBiofoulingonunderwaterpartsofman mademarinestructuresisamajoreconomicandtechni calproblemhavinginternationaldimensionsforthedevelopmentofoceanengineeringbecauseitnotonlyincreasesstaticandhydrodynamicloading,butalsoaffectscorrosioncharacteristicsandim pedesunderwaterinspectionandmaintenance (CallowandEdyvean ,1 990 ) .Duetodifferencesingeographicalpositionsandenvironmentalconditions,thedistributionofsessileorganismsvarieswitharea .Therefore ,understandingtheformationofbiofoulin… 相似文献
15.
Effect of salinity on growth and first sexual maturity of Exopalaemon carinicauda (Holthuis, 1950) 总被引：1，自引：0，他引：1
To determine the optimal salinity for growth and first sexual maturity of ExopaIaemon carinicauda, the effects of salinity on growth and reproductive performance of early juvenile prawns of E. carinicauda were evaluated under laboratory conditions. Postlarvae from the same female broodstock were reared at six salinity levels （5, 10, 15, 20, 25, and 30） for 12 weeks. The specific growth rate （SGR） and survival rate （SR） under different salinity levels in the first 6 weeks were calculated and compared. SGR was significantly influenced by salinity. Prawns reared in salinity of 10 grew significantly faster （P〈0.05） than those reared in salinities of 5, 20, 25, and 30. However, ANOVA confirmed that there was no significant effect among the six salinity levels on SR. For the next 6 weeks, the body length （BL）, body weight （BW） at the first sexual maturity, and the age at median sexual maturity （As0） of females were measured and compared. Female prawns reared at salinity of 10 presented significantly shorter A50, but no significant differences among the six salinity levels for BL and BW at the first sexual maturity were observed. Based on the above information, the optimal salinity for growth and first sexual maturity of juvenile E. carinicauda is approximately 10. 相似文献
16.
Effect of temperature and irradiance on the growth and reproduction of Enteromorpha prolifera J. Ag. （Chlorophycophyta, Chlorophyceae） 总被引：1，自引：0，他引：1
Effect of temperature and irradiance on growth and reproduction of Enteromorpha prolifera that bloomed offshore along the Qingdao coast in summer 2008, was studied. It was showed that E. prolifera propagated mainly asexually with specific growth rate (SGR) of 10.47 at 25°C/40 μmol m-2s-1. Under this condition, gametes with two flagellate formed and released in 5 days. At the beginning of the development, the unicell gamete divided into two cells with heteropolarity, and then the apical cell developed into thalli primordial cells, whereas the basal cell developed into rhizoid primordial cells. In 8-day culture, the monoplast gamete developed into juvenile germling of 240 μm in length. Unreleased gametes can develop directly within the alga body. E. prolifera could either reproduce through lateral branching or fragmenting except apomixis revealed by Microscopic observation. On aged tissue of E. prolifera, although the degraded pigments partially remained in faded algal filaments, numerous vegetative ceils could still divide actively in the algal tissues. 相似文献
17.
Loach （Misgurnus anguillicaudatus） is a commercially important fish in China and an ideal aquaculture species. However, culturists experience high larval and juvenile mortality during mass production. To provide insight into ways to improve larviculture techniques, we describe the morphological characteristics and behavior of loach during the larval and early juvenile stages. Yolksae larvae ranged from 2.8 to 4.0 mm body length （BL） between days 0 to 4; preflexion larvae ranged from 3.6 to 5.5 mm BL between days 4 to 6; flexion larvae ranged from 4.8 to 8.1 mm BL between days 5 and 14; and post-flexion larvae ranged from 7. l to 15.7 mm BL between days 11 to 27; the minimum length and age of juveniles was 14.1 mm BL and 23 d, respectively. Loach are demersal from hatch through to the early juvenile stages. A suite of morphological characteristics （e.g., external gill filament and ventral mouth opening） and behavioral traits have developed to adapt to demersal living. We observed positive allometric growth in eye diameter, head length, head height, and pectoral fin length during the early larval stages, reflecting the priorities in the development of the organs essential for survival. Our results provide a basis for developing techniques to improve the survival of larval and juvenile loach during mass production. 相似文献
18.
《中国海洋大学学报(英文版)》2017,(1)
This study investigates the migration and distribution of the warm-temperate fish Nibea albiflora. Their spawning migration and wintering migratory routes within in the Yellow Sea are described in detail. Considering the main physical features and environment of the Yellow Sea, it appears to be have one wintering ground and three migratory routes from the wintering ground to the spawning grounds. The fish begin to migrate from the wintering ground to the spawning grounds in the northwest region of the Yellow Sea in late March. The Yellow Sea has three spawning grounds. The first is located near the Yalu River on the Liaodong Peninsula and the second one is located in Rushan Bay of Shandong Peninsula. The third spawning ground is located in Haizhou Bay in the southern region of the Yellow Sea. This study found that the temperature of the Yellow Sea influences the migration of N. albiflora, and that the migratory routes coincide with the thermal fronts in the sea. Nutrients for juvenile fish are taken from the coastal upwelling area. Chlorophyll is a good environmental indicator of phytoplankton biomass and thereby provides the status of biological resources. Different types of sediment in near-shore zones are also of practical significance for the growth of fish. The study of the effects of marine environments on the migration of various fishes is not only significant to the fishing industry, but can also provide a scientific basis for the understanding of the ecological implications of the relevant physical processes. 相似文献
19.
Existing quantitative migration studies are mainly at the inter-region or inter-province level for lacking of detailed geo-referenced migration data.Meanwhile,few of them integrate explorative spatial data analysis and spatial regression model into migration analysis.Based on aggregated registered floating population data from 2005 to 2008,the phenomena that population floating to Yiwu City in Zhejiang Province is analyzed at the provincial and county levels.The spatial layout of Yiwu’s pull forces is proved as a V-shaped pattern excluding Sichuan Province based on map visualization method.Using the migration ratio in 2007 as an explanatory variable,two models are compared using ordinary least square,spatial error model and spatial lag model methods for county-level data in Jiangxi and Anhui provinces.The model with migration stock provides an improved fitting over the model without migration stock according to the model fitting results.The floating population flocking into Yiwu City from Jiangxi is determined mostly by migration stock while the determinant factors are migration stock and distance to Yiwu City for Anhui.The distance-decay effect is true for migration flow from Anhui to Yiwu City while the distance rule is not confirmed in Jiangxi with the best fitting model.The correlation between per capita net income of rural labor forces and migration ratio is not significant in Jiangxi and significant but at the 0.1 level only in Anhui.Further analysis shows that the distance,income and man-land ratio are important factors to explain population floating at earlier stage.However,as the dynamic population floating process evolves,the determinant factor would be migration stock. 相似文献
20.
A Review of Interaction Between Neon Flying Squid (Ommastrephes bartramii) and Oceanographic Variability in the North Pacific Ocean 总被引：4，自引：0，他引：4
《中国海洋大学学报(英文版)》2015,(4)
The neon flying squid(Ommastrephes bartramii) is a short-lived opportunistic species widely distributed in subtropical and temperate waters in the North Pacific Ocean. The life cycle of O. bartramii from planktonic eggs to nektonic adults is closely linked to oceanographic conditions. The fluctuations in O. bartramii abundance and distribution tend to increase and widen continuously due to the heavy influences of ocean-climate events on various spatio-temporal scales. In this study, we reviewed the interaction between O. bartramii and oceanography variability in the North Pacific with respect to large-scale climatic-oceanic phenomena including El Ni?o, La Ni?a, Kuroshio, Oyashio and Pacific Decadal Oscillation(PDO), as well as regional environmental variables such as sea surface temperature(SST), sea surface height(SSH), sea surface salinity(SSS), chlorophyll-a(Chl-a) concentration, and plankton density. The population dynamics of O. bartramii is mediated mainly by meso- and large-scale climatic-oceanic events(e.g., Kuroshio and Oyashio Currents) rather than other local environmental conditions(e.g., SST and Chl-a concentration), because all of the oceanographic influences are imposed on the context of large-scale climate changes(e.g., PDO). An unstructured-grid finitevolume coastal ocean model coupled with an individual-based model is proposed to simulate relevant physical-biological oceanographic processes for identifying ocean-climate influence and predicting O. bartramii distribution and abundance in the North Pacific. Future research needs to be focused on improving the knowledge about early life history of O. bartramii and evaluating the relationship between marine physical environment and two separate passive drifting life stages of O. bartramii including free-floating eggs and planktonic paralarvae. 相似文献