Mercenaria mercenaria is a bigger shellfish with high value,longer life cycle,fast growth,power adaptability,and wide adapt rang for temperature and salinity.Its age and growth were studied based on 286 samples caught from northern New York,USA.The results showed that: there were two fast growth periods,spring and autumn,and two slow growth periods,winter and summer,in a year for this clam.Two annual rings,the winter ring and summer ring,were formed when the growth was very slow or stop.The age rang of parent clam was 3-6.The relationship between shell height and body weight could be expressed as W=2.8961×10-4L3.0024.The von Bertallanffy growth equation,Lt=79.17[1-e-0.51（t+0.01）],Wt=145.22[1-e-0.51（t+0.01）]3,was used to describe the growth of this clam.The body weight growth inflection age was 2.15.It is thought that the clam culture has a bright future as the seeds breeding and culture has been succeed in Shandong Province.
