The genetic variation and differentiation of the razor clam Sinonovacula constricta distributed along the coast of China were studied through amplified fragment length polymorphism(AFLP) analysis.Six primer combinatio...The genetic variation and differentiation of the razor clam Sinonovacula constricta distributed along the coast of China were studied through amplified fragment length polymorphism(AFLP) analysis.Six primer combinations generated 193 fragments.The He values varied from 0.322 to 0.463 and the percentage of polymorphic loci ranged from 74.1% to 98.4%,which indicates a high level of genetic diversity.Cluster analysis by Nei's pairwise distance grouped all specimens by geographical origins.AMOVA consistently showed that genetic variation among populations was 8.71%,and most of the variation came from the genetic variation within populations(91.29%).Genetic differentiation among the six populations was moderate;pairwise FST ranged from 0.0282 to 0.1480,which indicated that S.constricta populations along the coast of China are genetically connected.Among all the six populations,the Beihai population is the mostly differentiated from the others,suggesting that Hainan Island and Leizhou Peninsula act as barriers to gene flow.All populations abide isolation by distance model as indicated by Mantel test,except for ZS(Zhoushan) and YQ(Yueqing) populations.Information obtained in this study will provide guidelines for conservation and fishery management of this species in the future.展开更多
Population dynamics of the Balanus improvises （Crustacean： Cirripedia） was studied in three stations Amirabad, Khazarabad in the eastern part and Noor in the central part of the Southern Coasts of the Caspian Sea. ...Population dynamics of the Balanus improvises （Crustacean： Cirripedia） was studied in three stations Amirabad, Khazarabad in the eastern part and Noor in the central part of the Southern Coasts of the Caspian Sea. Sampling procedure was carried out monthly from July 2007 to July 2008. In this study longitudinal diameter aperture （orifice or opercula diameter） of4118 individuals as well as dry weight and ash free dry weight of 141 barnacles were measured. Barnacle population density decreased in all three stations during autumn and winter. Barnacle density in Khazarabad were significantly higher than the other two stations （P 〉 0/05）. In this study, for dry weight and ash free dry weight maximum 247 and 122 mg and minimum 0/5 and 0/25 mg were obtained respectively. Emergence of a young cohort in March 2008, indicates the reproduction season and larval recruitment at this time. Also the frequency of the larval recruitment from April 2004 until mid-summer had increased. Opercula diameter of B. improvisus correlated with dry weight （R2 = 0/87, n = 115） and ash free dry weight （R2= 0/77, n = 115）. In addition, two equations for correlation of opercula diameter with dry weight （W = 0/49 L2/6, Re= 14） and ash free dry weight （W = 0/16 L2/81, Re = 18/8） for this species were calculated.展开更多
Chrysaora cf.caliparea,one of the most abundant medusae species in India,seems to be an important predator in the coastal waters of Bay of Bengal.The ability of Chrysaora cf.caliparea to feed at maximum rate in high p...Chrysaora cf.caliparea,one of the most abundant medusae species in India,seems to be an important predator in the coastal waters of Bay of Bengal.The ability of Chrysaora cf.caliparea to feed at maximum rate in high prey concentrations implies that this jellyfish can efficiently exploit dense prey patches,at least for a short period.This study presents preliminary information regarding digestion and feeding rate upon copepods in a warm water environment.The ingestion rate of the average-sized medusae Chrysaora cf.caliparea is well balanced in nature,which in turn implies that this jellyfish is tuned for optimal utilization of available prey resources.Comparison with earlier research indicates that prey escape speed is one important factor governing which prey will be captured.A full understanding of predation mechanics awaits further investigation of both predator and prey behavior.However,because of the scarcity of long-term quantitative population data most insights have to be made indirectly.Nevertheless,low abun-dance of Chrysaora cf.caliparea in the water column during summer (May 2007) and the overall annual abundance seem not to con-siderably affect the zooplankton population,especially copepods.The present work contributes to the knowledge of prey-predator relationship of the forgotten fauna in Indian waters,which is especially crucial for understanding the process of ecological recovery of coastal water environment.展开更多
Barito Delta morphodynamic had contradictive role with its potency and problem. Potency in Barito Delta may support the development of Banjarmasin City, but development of Barito Delta may decrease the capacity of tra...Barito Delta morphodynamic had contradictive role with its potency and problem. Potency in Barito Delta may support the development of Banjarmasin City, but development of Barito Delta may decrease the capacity of transportation in Barito River. Multitemporal topographic map and Landsat satellite image during the period 1862-2008 were used to analyze the long-term delta morphodynamic. The analysis consisted of delta growth, yearly growth, growth orientation, delta shape, and shoreline changes. The research showed that the Barito Delta had developed during the period 1862-2008. Barito Delta had developed to south orientation. The growth of Barito Delta during the period 1862-1946 was 27.82 km^2 or 0.33 km^2/year. However, during the period 1946-1997, Barito Delta growth was 175.82 km^2 or 3.45 km^2/year. Area of Barito Delta decreased during the period 1997-2004. The reduction of Barito Delta area was 4.73 km^2 or 0.67 km^2/year. Area of Barito Delta in years 2004-2008 increased about 3.38 km^2 or 0.84 km^2/year Shoreline during the period 1862-2008 had changed. Accretion occurred in Kuala Lupak River during the period 1862-1997, but erosion occurred during the period 1997-2004. The delta morphodynamics were influenced by human activities in watershed and delta such as landuse change and land degradation.展开更多
基金supported by the grants from National High Technology Research and Development Program (2007AA09Z433)the Major State Basic Research Development Program of China (973 Program, 2010CB-126406)Chinese Ministry of Education (707041)
文摘The genetic variation and differentiation of the razor clam Sinonovacula constricta distributed along the coast of China were studied through amplified fragment length polymorphism(AFLP) analysis.Six primer combinations generated 193 fragments.The He values varied from 0.322 to 0.463 and the percentage of polymorphic loci ranged from 74.1% to 98.4%,which indicates a high level of genetic diversity.Cluster analysis by Nei's pairwise distance grouped all specimens by geographical origins.AMOVA consistently showed that genetic variation among populations was 8.71%,and most of the variation came from the genetic variation within populations(91.29%).Genetic differentiation among the six populations was moderate;pairwise FST ranged from 0.0282 to 0.1480,which indicated that S.constricta populations along the coast of China are genetically connected.Among all the six populations,the Beihai population is the mostly differentiated from the others,suggesting that Hainan Island and Leizhou Peninsula act as barriers to gene flow.All populations abide isolation by distance model as indicated by Mantel test,except for ZS(Zhoushan) and YQ(Yueqing) populations.Information obtained in this study will provide guidelines for conservation and fishery management of this species in the future.
文摘Population dynamics of the Balanus improvises （Crustacean： Cirripedia） was studied in three stations Amirabad, Khazarabad in the eastern part and Noor in the central part of the Southern Coasts of the Caspian Sea. Sampling procedure was carried out monthly from July 2007 to July 2008. In this study longitudinal diameter aperture （orifice or opercula diameter） of4118 individuals as well as dry weight and ash free dry weight of 141 barnacles were measured. Barnacle population density decreased in all three stations during autumn and winter. Barnacle density in Khazarabad were significantly higher than the other two stations （P 〉 0/05）. In this study, for dry weight and ash free dry weight maximum 247 and 122 mg and minimum 0/5 and 0/25 mg were obtained respectively. Emergence of a young cohort in March 2008, indicates the reproduction season and larval recruitment at this time. Also the frequency of the larval recruitment from April 2004 until mid-summer had increased. Opercula diameter of B. improvisus correlated with dry weight （R2 = 0/87, n = 115） and ash free dry weight （R2= 0/77, n = 115）. In addition, two equations for correlation of opercula diameter with dry weight （W = 0/49 L2/6, Re= 14） and ash free dry weight （W = 0/16 L2/81, Re = 18/8） for this species were calculated.
基金supported by FAPESP 2003/02433-0,2003/02432-3 and 2010/50174-7)
文摘Chrysaora cf.caliparea,one of the most abundant medusae species in India,seems to be an important predator in the coastal waters of Bay of Bengal.The ability of Chrysaora cf.caliparea to feed at maximum rate in high prey concentrations implies that this jellyfish can efficiently exploit dense prey patches,at least for a short period.This study presents preliminary information regarding digestion and feeding rate upon copepods in a warm water environment.The ingestion rate of the average-sized medusae Chrysaora cf.caliparea is well balanced in nature,which in turn implies that this jellyfish is tuned for optimal utilization of available prey resources.Comparison with earlier research indicates that prey escape speed is one important factor governing which prey will be captured.A full understanding of predation mechanics awaits further investigation of both predator and prey behavior.However,because of the scarcity of long-term quantitative population data most insights have to be made indirectly.Nevertheless,low abun-dance of Chrysaora cf.caliparea in the water column during summer (May 2007) and the overall annual abundance seem not to con-siderably affect the zooplankton population,especially copepods.The present work contributes to the knowledge of prey-predator relationship of the forgotten fauna in Indian waters,which is especially crucial for understanding the process of ecological recovery of coastal water environment.
文摘Barito Delta morphodynamic had contradictive role with its potency and problem. Potency in Barito Delta may support the development of Banjarmasin City, but development of Barito Delta may decrease the capacity of transportation in Barito River. Multitemporal topographic map and Landsat satellite image during the period 1862-2008 were used to analyze the long-term delta morphodynamic. The analysis consisted of delta growth, yearly growth, growth orientation, delta shape, and shoreline changes. The research showed that the Barito Delta had developed during the period 1862-2008. Barito Delta had developed to south orientation. The growth of Barito Delta during the period 1862-1946 was 27.82 km^2 or 0.33 km^2/year. However, during the period 1946-1997, Barito Delta growth was 175.82 km^2 or 3.45 km^2/year. Area of Barito Delta decreased during the period 1997-2004. The reduction of Barito Delta area was 4.73 km^2 or 0.67 km^2/year. Area of Barito Delta in years 2004-2008 increased about 3.38 km^2 or 0.84 km^2/year Shoreline during the period 1862-2008 had changed. Accretion occurred in Kuala Lupak River during the period 1862-1997, but erosion occurred during the period 1997-2004. The delta morphodynamics were influenced by human activities in watershed and delta such as landuse change and land degradation.
