Update information on the spawning of yellowfin tuna, Thunnus albacares, in the western central Atlantic
Arocha, F.; Lee, D.W.; Marcano, L.A.; Marcano, J.S.
International Commission for the Conservation of Atlantic Tunas Collective Volume of Scientific Papers 52: 167-176
Information on the spawning of yellowfin tuna (Thunnus albacares) from the western central Atlantic is updated from data collected in 1999. Spawning was analyzed based on oocyte development from ovary samples collected. Of the 133 ovaries used in the updated analysis, 1.5% (2 ovaries) of the sampled specimens were considered mature inactive, 2.3 % (3 ovaries) were considered maturing, 50.4% (67 ovaries) were identified as mature, 12% (16 ovaries) were considered ripe, 31.5% (42 ovaries) were identified as ready-to-spawn, and 2.3% (3 ovaries) were in spawned condition. Average batch fecundity for yellowfin tuna was estimated to be 2.1H106 oocytes (n=6), which ranged from 1.2H106 for a 132 cm FL (31.8 kg DWT) to 4.0H106 for a 142 cm FL (42.7 kg DWT) female. The average cost of a single spawning is about 0.83% of body weight. Spawning continues to take place in the Gulf of Mexico between May and August and in the southeastern Caribbean Sea between July and September.