ABSTRACT
Among the 15 tuna species (Scombridae, Thunnini) found worldwide, bluefin tunas grow to be the largest (Collette et al. 2001). The angling record for the heaviest tuna is 679 kg for an Atlantic bluefin tuna (Thunnus thynnus) caught off Nova Scotia in 1979 (Collette and Nauen 1983). The heaviest documented Pacific bluefin (Thunnus orientalis) and southern bluefin (Thunnus maccoyii) are 555 kg and 260 kg respectively (Foreman and Ishizuka 1990; Nakamura 1990). Given the large body size of these animals, the question arises: how fast do they grow, what is their life-span and at what size or age do they start to reproduce?
