The Instituto Español de Oceanografía (IEO) began a research project with tuna fish, with the objective of obtaining stocks of several species and determine their capacity to reach sexual maturity and spawn under captivity in on-land facilities. During the last two years, several experiences have been carried out to establish the viability of maintaining stocks of different tuna fish in captivity (Thunnus thynnus, T. albacares, and T. obesus), in ponds located in on-land culture facilities, Centro Oceanográfico de Canarias in Tenerife. This study has been carried out with three fish stocks in 1997 (July to December) and 1998-1999 (August to February) in circular tanks of 50 m3 (7 m diameter), 250 m3 (13 m diameter) and race way tanks of 500 m3 (40 m length). Information has been obtained about the characteristics that the facilities should have for acclimatization and stocking of tuna, as well as to optimize manipulations of fish.