Question: A friend told me that state Fish and Wildlife fish hatcheries are now producing and stocking triploid fish. Is this true?

Answer: Yes! These vivacious, catchable, sterilized rainbow trout are produced by California Department of Fish and Wildlife (CDFW) fish hatcheries. Triploid fish have an extra set of chromosomes (3N) as a result of pressure treatment, combined with carefully monitored temperature and time precision during egg fertilization. The resulting fish are sterile, making them a more ecologically sound option for recreational fishing in many waters across the State. The fish perform for anglers like a diploid (fertile) fish, many grow larger than the fertile diploids, and they are increasingly being produced in other states for recreational stocking throughout the country.