| In recent years, raft bivalve culture in shallow sea in China has inflicted heavy losses due to unreasonable exploitation. It is necessary to explore culture capacity and culture patterns by means of theory and practice. Not only the ingestion activity, absorption efficiency of A. japonicus on biodeposition but also the excretion activity of A. japonicus were studied in this paper through indoor experiment and in-situ determination. Meanwhile, the growth performance of A. japonicus in polyculture system of A japonicus and bivalves in shallow sea were compared, new-style patterns and capacity of A. japonicus culture were determined.From April to June of 2001, A. japonicus were cultured in indoor breeding tanks in Institute of Oceanography, Chinese Academy of Sciences under the condition of natural seawater temperature, fed on biodeposition. Ingestion rate, absorption rate, oxygen consume rate, and ammonia excrete rate of A. japonicus were determined regularly. The mainly results are as follows:1. The weight gains for A. japonicus is significant when fed on biodeposition. The individual mean weight increased more than 1.5 times in two months and the instantaneous growth rate reached about 2-fold. The average ingestion rates(g/g.h) of A. japonicus on biodepositon were 0.00324, 0.00648and 0.00959 respectively for macro-, meso- and micro-of A. japonicus under the mean water temperature of 13.2-22.3 *C. The results above indicate that biodeposition, feedstuff of A. japonicus, played an important role in the growth of A. japonicus and it is important for A. japonicus cultured in indoors and enhanced in the sea.2. The average absorption rates of A. japonicus on biodepositon are 7.32%, 13.49% and 17.61% for macro-, meso- and micro-size A. japonicus. Highest absorption rates of macro-size of A. japonicus were 15.32% at the temperature of 15.13C.The highest absorption rates of meso- and micro- of A japonicus were 20.35% and 23.00% respectively under the temperature of 17.36C. Absorption and utilization of biodeposition by A. japonicus reduced the content of organic matter in the bottom , and restrained the accumulation and production of deleterious substances.3. The intensity of A. japonicus respiratory metabolize can be expressed by oxygen consume rate .When the temperature of water is 13.2C, 15.13C, 17.36C, 20.2C, 22.3 C,the regress average of the weight of A. japonicus. (W) and the absolutely mean oxygen consume rates(R) conform to the equation R^aW1", inwhich a:0.020-0.02109,mean is0.1155,b:0.4407~1.0690, mean 0.7549.As a while, the oxygen consume of A. japonicus. grows with the growth of temperature,the variation of temperature has a little affection on oxygen consume rate of the small ,on the the other hand the oxygen consume rate of big and middle A. japonicus. has a big change, and get the max under the temperature of 20.2'C.4.The excretion of A. japonicus. Is mainly expressed by ammonia excrete rates .under the different temperature , the relation of weight of A. japonicus. (W)and the absolutely mean ammonia excrete rates (A) can be expressed by regress equation : A=aWb, the mean value of a, b are5.794and 0.3932,respectively, The correlation of the equation is between 0.9664 and 0.9968.The mean ammonia excrete rates increases when temperature increases. The affection of the temperature on different A. japonicus. has some discrepancy, The max of ammonia excrete rates of big and middle A. japonicus can be attain when temperature is 17.36癈, and the highest of excrete rates were 2.417 and 4.863.5. The biodeposition. Ingestion rate, absorption rate, oxygen consume rate, and ammonia excrete rate of big and middle A. japonicus has a patent change after aestivation,but aestivation has a little affection on the growth and metabolize of small size of A. japonicus.From August 2001 to April 2002, Polyculture of A. japonicus and bay scallop, polyculture of A. japonicus and pacific oyster were conducted in Sishiliwan Bay in Yantai. The environmental status in culture area and growth of... |
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