Characteristic of population biology of the “sepetang” clam has been studied in
Dumai mangrove ecosystem from November 2010 to October 2011. This research
was to study the patterns of the population growth, mortality and recruitment of
the clam P. acutidens. Sampling was monthlyfrom plot 1 m x 1 m quadratic
transects. The result showed that growth pattern of P. acutidens was negative
allometric with asymptotic length (L∞) 92.71 mm.The annual growth coefficient
(K) and total mortalitywere 0.59 and 1.87 per year, respectively. The natural
mortality was probably related to environmental condition. The recruitment
occurred every month, the peaks occurred on April (15.93%) and August
(13.16%).