Abstract: The objective of this study is to determine the optimum ecological conditions for the cultivation of clam Meretrix meretrix, and to provide basic data for the habitat selection and suitability evaluations of artificial restocking of this species. The burrowing behavior of spat was observed under different temperature, salinity and sediment conditions. The results showed that the burrowing behavior of the clam into the soft sediment could be divided into three periods: preparation, burrowing and terminal. The burrowing period was involved in stretching foot, stacking shell and burrowing into the sand. The spat with shell length of 1.0 cm had longer preparation period (46.1 min) and digging time (7.6 min), while the spat with shell length of 2.0 cm had shorter preparation period (18.6 min) and digging time (4.0 min). Sandy sediment with little clay content was the best substrate for the spat of M. meretrix, and the most appropriate burrowing temperature for M. meretrix was 15-25 ℃. Moreover, the burrowing rate of the spats at 15-25 ℃ was greater than 80%, and the burrowing depth decreased with increasing the water temperature. The most suitable salinity for the spat of M. meretrix was 26. Burrowing behavior of the spat was impeded at salinity higher or lower than 26. In conclusion, our results suggest that it is better to artificially restock the spats with the shell length of 2 cm in the sandy sediment of the area when the water temperature is at 15-25 ℃ and the salinity reaches 26. Effectiveness of artificial restocking of M. meretrix could be significantly improved in this way.

Key words: soil organic carbon mineralization rate, soil enzyme kinetic parameter, temperature sensitivity.