Pacific oyster broodstocks in hatcheries are kept in optimum conditions so the production of large amounts of high quality eggs and sperm can be achieved. Pacific oyster females are very fecund, and individuals of 70-100 g live weight can produce 50-80 million eggs in a single spawn. Broodstock adults are held in tanks at 20-22 °C, supplied with cultured algae and with salinities of 25-32 ppt. These individuals can be induced to spawn by thermal shock treatment. Yet, the eggs from a small sample of females (about six) are more commonly stripped from the gonads using Pasteur pipettes and fertilized by sperm from a similar number of males.