It has been classed 856 species of the mollusks which belong to 120 families and five classes living in western coast of the Tonkin Gulf. The class Gastropod was the most abundant, with 449 species, the Bivalve with 3...It has been classed 856 species of the mollusks which belong to 120 families and five classes living in western coast of the Tonkin Gulf. The class Gastropod was the most abundant, with 449 species, the Bivalve with 368 species, the Scaphopoda with 10 species, the Cephalopods with 19 species and the Amphineura with eight species. Standing stock was estimated about 366,749 tons, that annually caught 80,000 tons. The causes of the resource depletion were human and natural, but the human factors played a key role. The fundamental orientations for developing the resources include： exploiting during harvest seasons, planning suitable aquaculture, moderate exploitation so the resources can restore themselves, combining exploitation and conservation.展开更多
In the past 20 a, the gulf-scale circulation in the Beibu Gulf has been commonly accepted to be driven by a wind stress or density gradient. However, using three sensitive experiments based on a three-dimensional baro...In the past 20 a, the gulf-scale circulation in the Beibu Gulf has been commonly accepted to be driven by a wind stress or density gradient. However, using three sensitive experiments based on a three-dimensional baroclinic model that was verified by observations, the formation mechanisms were revealed： the circula- tion in the northern Beibu Gulf was triggered by the monsoon wind throughout a year; whereas the southern gulf circulation was driven by the monsoon wind and South China Sea （SCS） circulation in winter and sum- mer, respectively. The force of heat flux and tidal harmonics had a strong effect on the circulation strength and range, as well as the local circulation structures, but these factors did not influence the major circulation structure in the Beibu Gulf. On the other hand, the Beibu Gulf Cold Water Mass （BGCWM） would disappear without the force of heat flux because the seasonal thermocline layer was generated by the input of heat so that the vertical mixing between the upper hot water and lower cold water was blocked. In addition, the wind-induced cyclonic gyre in the northern gulf was favorable to the existence of the BGCWM. However, the coverage area of the BGCWM was increased slightly without the force of the tidal harmonics. When the model was driven by the monthly averaged surface forcing, the circulation structure was changed to some extent, and the coverage area of the BGCWM almost extended outwards 100%, implying the circulation and water mass in the Beibu Gulf had strong responses to the temporal resolution of the surface forces.展开更多
A phylogenetic hypothesis for the Asian newts of the Tylototriton asperrimus group was generated using data from two mitochondrial fragments including COI and the ND1-ND2 regions. Four distinct clades （A, B, C, D） w...A phylogenetic hypothesis for the Asian newts of the Tylototriton asperrimus group was generated using data from two mitochondrial fragments including COI and the ND1-ND2 regions. Four distinct clades （A, B, C, D） were resolved with high nodal support within this monophyletic group. Clade A included T. asperrimus, T. hainanensis, T. notialis, ＂T. vietnamensis＂, and two unnamed salamander populations from Vietnam. Clade A, constituted the sister group of clades B ＋ C. Newly identified clade C likely represents a new cryptic species. Clade C was the sister group of T. wenxianensis. The true 7： vietnamensis exclusively constituted clade D. Our results bring into question some previous taxonomic decisions, and a revision is required. This study illustrates the necessity to include samples from type localities in taxonomic studies, and highlights the importance of fine-grained geographical sampling.展开更多
文摘It has been classed 856 species of the mollusks which belong to 120 families and five classes living in western coast of the Tonkin Gulf. The class Gastropod was the most abundant, with 449 species, the Bivalve with 368 species, the Scaphopoda with 10 species, the Cephalopods with 19 species and the Amphineura with eight species. Standing stock was estimated about 366,749 tons, that annually caught 80,000 tons. The causes of the resource depletion were human and natural, but the human factors played a key role. The fundamental orientations for developing the resources include： exploiting during harvest seasons, planning suitable aquaculture, moderate exploitation so the resources can restore themselves, combining exploitation and conservation.
基金The Guangxi Natural Science Foundation under contract No.2012GXNSFEA053001the program of"The Beibu Gulf forecast circulation system construction and its application to the coastal pollution transport"
文摘In the past 20 a, the gulf-scale circulation in the Beibu Gulf has been commonly accepted to be driven by a wind stress or density gradient. However, using three sensitive experiments based on a three-dimensional baroclinic model that was verified by observations, the formation mechanisms were revealed： the circula- tion in the northern Beibu Gulf was triggered by the monsoon wind throughout a year; whereas the southern gulf circulation was driven by the monsoon wind and South China Sea （SCS） circulation in winter and sum- mer, respectively. The force of heat flux and tidal harmonics had a strong effect on the circulation strength and range, as well as the local circulation structures, but these factors did not influence the major circulation structure in the Beibu Gulf. On the other hand, the Beibu Gulf Cold Water Mass （BGCWM） would disappear without the force of heat flux because the seasonal thermocline layer was generated by the input of heat so that the vertical mixing between the upper hot water and lower cold water was blocked. In addition, the wind-induced cyclonic gyre in the northern gulf was favorable to the existence of the BGCWM. However, the coverage area of the BGCWM was increased slightly without the force of the tidal harmonics. When the model was driven by the monthly averaged surface forcing, the circulation structure was changed to some extent, and the coverage area of the BGCWM almost extended outwards 100%, implying the circulation and water mass in the Beibu Gulf had strong responses to the temporal resolution of the surface forces.
基金supported by grants from the Ministry of Science and Technology of China(MOST Grant 2011FY120200)the National Natural Science Foundation of China(31090100,30870281)+1 种基金the Chinese Academy of Sciences(KSCX2-YW-Z-0807,KSCX2-EW-Z-2)the Bureau of Science and Technology of Yunnan province
文摘A phylogenetic hypothesis for the Asian newts of the Tylototriton asperrimus group was generated using data from two mitochondrial fragments including COI and the ND1-ND2 regions. Four distinct clades （A, B, C, D） were resolved with high nodal support within this monophyletic group. Clade A included T. asperrimus, T. hainanensis, T. notialis, ＂T. vietnamensis＂, and two unnamed salamander populations from Vietnam. Clade A, constituted the sister group of clades B ＋ C. Newly identified clade C likely represents a new cryptic species. Clade C was the sister group of T. wenxianensis. The true 7： vietnamensis exclusively constituted clade D. Our results bring into question some previous taxonomic decisions, and a revision is required. This study illustrates the necessity to include samples from type localities in taxonomic studies, and highlights the importance of fine-grained geographical sampling.
