Parameters related with the development of the gonad. GSI (a), the ratio between the ovarian area (gray part of the bars) and the total area of the gonad (full bars) (b) and the cell and nuclear diameters of the oocytes throughout the second RC and at the beginning of the third (c). Data represent means ± SEM n = 10–18 fish/month (a), n = 3 fish/month (b) and n = 111–269 cell/stage (c). Different letters denote statistically significant differences between the groups according to a Waller-Duncan test. Sg, Spermatogenesis; S, spawning; PS, post-spawning; TI, testicular involution; NFD, no further development; G, gametogenesis.