In recent years, significant progress on spawning induction in captive bluefin tuna (BFT, Thunnus thynnus), has been achieved providing the basis for the species’ domestication (Mylonas et al., 2007, 2010). To further promote the development of a self-sustained BFT aquaculture, we investigated pubertal development in BFT reared from an immature stage in captivity. Therefore, our major objectives were to evaluate maturational status of the brain-pituitary-gonadal (BPG) axis, and its responsiveness to exogenous hormones. Special emphasis was given to characterize the KiSS/GPR54 system that constitutes the trigger of puberty onset, and the gonadotropins follicle stimulating hormone (FSH) and luteinizing hormone (LH) that act as central regulators of gonadal development and gamete maturation.