Studies On Calcification And Metabolism Of Sinonovacula Constricta

The purpose of this study was to estimate the effects of p H,temperature and algae concentration on the energy budget of the clam Sinonovacula constricta.Adult clams were exposed to various treatments under three p H-values,three temperature-values and three algae concentration conditions.The ingestion,respiration,defecation,excretion of S.constricta was detected.The results indicated that:1.The effect of p H-values on the ingestion,respiration,defection,excreation of S.constricta had been studied at p H7.6,p H7.9 and p H8.2.The results showed that: In 23? seawater,with p H declining,S.constricta fed less Isochrysis galbana.And the respiration and defection rate also was declined.The temperature was 23 ? and the p H was 7.6,7.9 and 8.2.The results showed that the feeding rate,oxygen consumption rate,ammonia excretion rate and defecation rate decreased with the decrease of p H in the range of p H7.6 8.2.The calcification rate of the S.constricta decreased with the decrease of p H,and reached the lowest value of 0.19 ± 0.02?mol at p H7.6,and the calcination rate of the S.constricta decreased at 0.033 ± 0.002 mg·g^-1·h^-1.2.The effects of elevated temperature on the energy budget of the clam S.constricta.Adult clams were exposed to three-levels temperature treatments.The ingestion,respiration,defecation,excretion of S.constricta was detected.The results showed that: The feeding energy showed a peak change and the respiration energy and excretion energy showed slowly increased.In the range of 15²3?,the feeding energy of S.constricta increased significantly with the increase of temperature in the temperature of 23?,feeding energy reached the maximum value of 46.30J·h-1·g-1.When the temperature exceeded 23?,the feeding energy decreased,but the excretion energy continued to rise slowly.At 15 ?,the feeding energy,respiration energy and excretion energy of the S.constricta are reached the lowest.At in 23?,the maximum rate of feeding energy reached the highest.The calcification rate of S.constricta increased first and then decreased in the range of 15?³1?,in 15²3?,the calcification rate of S.constricta increased,and reached the maximum value of 0.34±0.06?mol·g^-1·h^-1 at 23?,in the range of 23³1?,the calcification rate of S.constricta decreased.3.Within the algae concentration range?3.0×105³.0×105 cells·m L-1?,the feeding energy,respiration energy and excretion energy of S.constricta had been studies.The results show that,the carbon source obtained by S.constricta were mainly consumed through breathing,and then they were directly discharged as dejection,with a small part being discharged by excretion.And the remaining carbon was mainly used for growth and development.One-way ANOVA showed that,the ingestion rate was significantly influenced by algae concentration?p<0.05?.In 3.0×105 cells·m L-1 algae concentration,the ingestion rate rached the maximum,and the oxygen rate ammonia excretion rate reached the maximum.