| The subjects of this thesis was conducted in the effects of such environmental factors as starvation, temperature and salinity on the Meretrix meretrix clam's energy metabolism and the feeding physiology and energy balance of clams in modeling runing water system in different quarters.1. The effects of temperature on energy balance of three kinds(shell length from 26.16cm to 51.50cm)of clams was studied in march 2009. The temperature gradient was set in 18℃,22℃,26℃and 30℃respectively and the indexes measured were oxygen consumption rate and ammonia excretion rate. The results indicated that the oxygen consumption rate rose along with temperature during 18℃～30℃and so did the ammonia excretion during 18℃-26℃which reached maximum at 26℃and declined as the temperature rose. The temperature had a siganificant effect on the clam's oxygen consumption and ammonia excretion(P<0.01). The oxygen consumption rate presented no sign of decline which indicated that the dendurance temperature of clams is over 30℃. The clam's O/N value rose significantly during 26℃～30℃, which indicated that clams'metabolism varied intensively. The average respiration value of clams of three different specifications were 6.31 during 26℃～30℃, which was much higher than 2.28 during 18℃～22℃and 3.43 during 22℃～26℃. This indicated that clams were much more adapted to the temperature gradient from 18℃to 26℃, and the smaller size may be more adaptive to a higher temperature.2. The study of effects of salinity on three different specifications of clams'energy metabolism was carried in may 2009. The subjects were divided into two groups-----24h mutation group and cultivation group. The salinity set in the expriment were 11, 16, 21, 26, 31 and 36. The index mensurated were oxygen consumption and ammonia excretion. The results indicated that the salinity over 36 exceeds the clam's endurance range. The oxygen consumption rate of mutation group decreased with the rose of salinity , reaching minimum at 21℃, and the oxygen consumption rate rose along with the salinity from 21 to 36. The ammonia excretion rate decreased with the salinity rose from 11 to 31. During the 24h mutation, salinity had a distinct effects on the oxygen consumption rate(P<0.05)and a especially distinct effect on the ammonia excretion(P<0.01). The oxygen consumption rate and ammonia excretion rate of the cultivation group had two different trends: the oxygen consumption rate and ammonia excretion rate of bigger size rose along with the salinity, reaching maximum at 21, and decreased with the salinity rose which differentiated distinctively(P<0.01). The oxygen consumption rate and ammonia excretion rate of clams of small and middle size had a trend of rise-decrease-rise-decrease with the rose of salnity. The difference of oxygen consumption rate and ammonia excretion rate was indistinctive at the salinity from 11 to 26(P>0.05)while the oxygen consumption rate differetiated distinctively when the salinity was below 16 or over 26 (P<0.05)and the ammonia rexcretion rate varied distinctively (P<0.01),which indicated that clams were adaptive to seawater of salinity from 11 to 26 and the most adaptive salinity was at about 21. When the salinity varied, clams might adapt to the environmental change in short trem based on their internal sysytem but the normal metabolism, growth and breed would be affected once their endurance range was exceeded for a long term.3. The study of effcts of long term starvation on clams'energy metalbolism was carried from October to November 2008. The starvation timing were 1d, 3d, 5d, 7d, 10d, 13d, 20d, 27d, 35d and the indexes measured were oxygen consumption rate and ammonia excretion rate. The results indicated that starvation had distinctive effects on both oxygen consumption rate and ammonia excretion rate(P<0.01). The oxygen consumption rates of clams of three different specifications rose along with the time duration from 1 to 7 days and decreased with the time duration after 7 days. The ammonia excretion rate rose along with the time duration from 1 to 7 days and, after 10 days, the oxygen consumption rate decreased with the time duration. The increase of O/N value with time duration indicated that clams's energy were mainly provided by protein and fat at the beginning of starvation and, without enough food and protein consumed, fat and carbocyclic become main energy as time expanded. The study found simutaneously that clams of big size were much more adaptive to starvation han clams of smaller size.4. The measuration of food intake parameter of clams of three specifications was conducted by modeling loacl running water system in August and November 2008. The estimation of clams'carbon balance was based on energy balance principle. The results indicated that specification had a comparatively large effects on food intake carbon, manure carbon, respiration carbon, excretion carbon and growth carbon. Generally , under same condition, the larger the specification of clams were, the smaller the food intake carbon per kilogram dehydrated clam meat were at unit time, while the absolute value of food intake carbon, manure carbon, respiration carbon, excretion carbon and growth carbon in August was much more higher than that of same clams of specifications in November. The allocation proportion of manure energy and growth energy were directly proportional to specifications while that of respiration energy and excretion energy were inversely proportional to specifications.
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