The white clamp (Protothaca asperrima) is a bivalve which supports a intensive capture by inhabitants of Bique beach, Arraiján, Panama. In order to understand the reproductive behavior of the population of this species was carried a study on that beach from 1995 to 1996 to determine the reproduction of this specie. Each month 20 individuals were collected, measuring its biomass and gonadal development by histology. Our results show that this species has a continual and asynchronic

reproductive cycle with two maximal spawning seasons, the higher one in January and the other one, smaller, in November, related to statistically with temperature and salinity Both seasons fit with the higher individual biomass. Therefore, it suggests that this specie has two spawning period in Bique beach which is not related statistically with temperature and salinity.