An 8-week growth trial was conducted to determine dietary arginine requirement for juvenile Pacific white shrimp Litopenaeus vannamei （Boone） with an initial average body weight of 0.47 g reared in low-salinity wat...An 8-week growth trial was conducted to determine dietary arginine requirement for juvenile Pacific white shrimp Litopenaeus vannamei （Boone） with an initial average body weight of 0.47 g reared in low-salinity water （0.50-1.50 g L-1）. Six isonitrogenous and isoenergetic semipurified diets （crude protein 360 g/kg and gross energy 19.70 kJ/g） were formulated with fish meal and wheat gluten as the intact protein source.展开更多
Four experimental diets were fed to turbet to examine the effect of fish bydrolyside and ultra filtered fish hydrolysafe on growth performate feed utilization and growth regulation using diets low in dietary fish meal...Four experimental diets were fed to turbet to examine the effect of fish bydrolyside and ultra filtered fish hydrolysafe on growth performate feed utilization and growth regulation using diets low in dietary fish meal inclusion. Diets A, B contained 3.7%,1.2% fish hydrolysate to replace fish meal respectively and the fish hydrolysate in two diets was ultra filtered to keep low molecular weight compounds. The diets A,展开更多
Although China has established more than 600 wetland nature reserves, conservation gaps still exist for many species, especially for freshwater fishes. Underlying this problem is the fact that top-level planning is mi...Although China has established more than 600 wetland nature reserves, conservation gaps still exist for many species, especially for freshwater fishes. Underlying this problem is the fact that top-level planning is missing in the construction of nature reserves. To promote the development of nature reserves for fishes, this study took the middle and lower reaches of the Yangtze River basin(MLYRB) as an example to carry out top-level reserve network planning for fishes using approaches of systematic conservation planning. Typical fish species living in freshwater habitats were defined and considered in the planning. Based on sample data collected from large quantities of literatures, continuous distribution patterns of 142 fishes were obtained with species distribution modeling and subsequent processing, and the distributions of another eleven species were artificially designated. With the distribution pattern of species, Marxan was used to carry out conservation planning. To obtain ideal solutions with representativeness, persistence, and efficiency, parameters were set with careful consideration regarding existing wetland reserves, human disturbances, hydrological connectivity, and representation targets of species. Marxan produced the selection frequency of planning units(PUs) and a best solution. Selection frequency indicates the relative protection importance of a PU. The best solution is a representative of ideal fish reserve networks. Both of the PUs with high selection frequency and those in the best solution have low proportions included in existing wetland nature reserves, suggesting that there are significant conservation gaps for fish species in MLYRB. The best solution could serve as a reference for establishing a fish reserve network in the MLYRB. There is great flexibility for replacing selected PUs in the solution, and such flexibility facilitates the implementation of the solution in reality in case of unexpected obstacles. Further, we suggested adopting a freshwater management framework in the implementation of such solution.展开更多
文摘An 8-week growth trial was conducted to determine dietary arginine requirement for juvenile Pacific white shrimp Litopenaeus vannamei （Boone） with an initial average body weight of 0.47 g reared in low-salinity water （0.50-1.50 g L-1）. Six isonitrogenous and isoenergetic semipurified diets （crude protein 360 g/kg and gross energy 19.70 kJ/g） were formulated with fish meal and wheat gluten as the intact protein source.
文摘Four experimental diets were fed to turbet to examine the effect of fish bydrolyside and ultra filtered fish hydrolysafe on growth performate feed utilization and growth regulation using diets low in dietary fish meal inclusion. Diets A, B contained 3.7%,1.2% fish hydrolysate to replace fish meal respectively and the fish hydrolysate in two diets was ultra filtered to keep low molecular weight compounds. The diets A,
基金supported by fund of State Forestry Administration of China-United Nations Development Program/Global Environment Facility(83911 NP-2014-007)
文摘Although China has established more than 600 wetland nature reserves, conservation gaps still exist for many species, especially for freshwater fishes. Underlying this problem is the fact that top-level planning is missing in the construction of nature reserves. To promote the development of nature reserves for fishes, this study took the middle and lower reaches of the Yangtze River basin(MLYRB) as an example to carry out top-level reserve network planning for fishes using approaches of systematic conservation planning. Typical fish species living in freshwater habitats were defined and considered in the planning. Based on sample data collected from large quantities of literatures, continuous distribution patterns of 142 fishes were obtained with species distribution modeling and subsequent processing, and the distributions of another eleven species were artificially designated. With the distribution pattern of species, Marxan was used to carry out conservation planning. To obtain ideal solutions with representativeness, persistence, and efficiency, parameters were set with careful consideration regarding existing wetland reserves, human disturbances, hydrological connectivity, and representation targets of species. Marxan produced the selection frequency of planning units(PUs) and a best solution. Selection frequency indicates the relative protection importance of a PU. The best solution is a representative of ideal fish reserve networks. Both of the PUs with high selection frequency and those in the best solution have low proportions included in existing wetland nature reserves, suggesting that there are significant conservation gaps for fish species in MLYRB. The best solution could serve as a reference for establishing a fish reserve network in the MLYRB. There is great flexibility for replacing selected PUs in the solution, and such flexibility facilitates the implementation of the solution in reality in case of unexpected obstacles. Further, we suggested adopting a freshwater management framework in the implementation of such solution.
