Within the framework of the SELFDOTT project, captive-reared bluefin tuna (Thunnus thynnus) maintained in captivity since 2007 in Cartagena (Spain) produced massive spawning during the natural period for this species in the Mediterranean Sea (June-July). The fish were induced with GnRHa implants in 2008 and 2009. In 2008 no spawnings were detected. From 2009, massive spawnings occurred being spontaneous (without hormone implants) in 2010 and 2011. The total egg collection was 140 million in 2009, 60 million in 2010 and 160 million in 2011.7º Programa Marco de la Unión Europea, “Food, Agriculture, Fisheries and Biotechnology" del Proyecto SELFDOTT (From capture based to SELF-sustained aquaculture and Domestication Of bluefin tuna, Thunnus thynnus)” GA 212797