, cryopreservation techniques are used so that gametes of threatened species can be preserved in viable and fertile condition for long periods . This is categorized as an ex situ (off site) conservation approach, which involves taking threatened organisms or their genetic material out of their natural habitats to be protected and given special care . The sources explicitly list the cryopreservation of gametes as an advanced method of ex situ conservation, distinguishing it from in situ (on-site) methods that protect the entire natural habitat .