Duck skeletal muscle acylphosphatase: Primary structure

The complete amino acid sequence of duck skeletal muscle acylphosphatase is presented. The sequence was studied by the manual Edman degradation of the complete series of tryptic peptides and the amino acid composition of peptic peptides. The NH₂-terminus is acetylated, and the polypeptide consists of 102 amino acid residues. The sequence is compared with other known acylphosphatases from the skeletal muscle of several vertebrate species.     

Environmental and Socioeconomic Constraints to the Development of Freshwater Fish Aquaculture in China

In this article, we provide an overview, on freshwater fish aquaculture in P.R. China, with special emphasis on pond fish culture. We describe the history, ecology (trophic structure and species reared), and technological aspects (including inputs/outputs, yields, labor productivity, and fossil energy use) of freshwater fish production and analyze its role in relation to the socioeconomic context. We discuss the prospects for intensification of production. In China, freshwater fish aquaculture has always been closely linked to cultivation of crops and animal husbandry, that is, feed inputs are in the form of agricultural wastes. The close integration with the farming system at large results in an efficient use of nutrients, low environmental loading, and little dependence on fossil energy inputs. About 7 to 9 different fish species, mainly herbivores, are kept in the same pond and efforts are made to maintain as much as possible the natural mechanisms of matter regulation and energy flows within the pond ecosystem. However, ecological compatibility is paid for by relatively low productivity, both per hectare of waterbody and per hour of labor input. If the throughput of freshwater fish production per unit of area and labor are to be dramatically increased, the equilibrium of the traditional integrated system will be difficult to maintain.