Ontogenetic and temperature-dependent changes in tolerance to hypoxia and hydrogen sulfide during the early life stages of the Manila clam Ruditapes philippinarum.

Wind-induced upwelling of hypoxic waters containing hydrogen sulfide (HS) sometimes causes mass mortalities of aquatic organisms inhabiting coastal areas, including the hypoxia-tolerant Manila clam Ruditapes philippinarum. We examined the tolerance of Manila clam to HS under controlled laboratory conditions. Larvae and juveniles obtained by artificial fertilization or from a wild population were exposed to normoxic or to hypoxic water with or without un-ionized HS (concentrations, 0.