DeMarfini et al.: Body sizes at maturation and at sex change, and spawning seasonality and sex ratio of Hyporthodus quernus 
129 
Figure 3 
Photomicrographs of select representative gonads illustrating key reproductive stages of 
Hawaiian grouper ( Hyporthodus quernus). (A) Vestigial bisexual, 333 mm total length 
(TL); ( B ) immature bisexual, 495 mm TL; (C) mature female, 624 mm TL; (D) transi- 
tional (female-male) mature fish, 913 mm TL; (E) mature male, 820 mm TL; and (F) 
mature male, 919 mm TL. CN = chromatin nucleolar oogonium; PN=perinucleolar oocyte; 
PT=previtellogenic oocyte; VT=vitellogenic oocyte; HYD= hydrated oocyte; POF= postovula- 
tory follicle; SC = spermatocytes (Sertoli nurse cells); SG = spermatogonia; SZ = spermatozoa 
in sperm duct; SM = smooth muscle; BB = gamma-stage atretic “brown body”; LU = lumen. 
Black scale bars: 100 pm. 
GSI s produced qualitatively similar results (Fig. 6) but 
the statistical clarity of monthly patterns improved 
when based on the more precise body-size-corrected 
RGIs. 
The proportional incidence of active spawners, in- 
cluding “imminent” females ready to spawn (ovaries 
containing hydrated oocytes), recently spawned fish 
(ovaries containing recognizable [i.e. , less-than-several- 
days-old; Fitzhugh and Hettler, 1995] postovulatory 
follicles), or both, also indicated a main February-June 
period of spawning with a peak in March (Fig. 7). 
Eleven (16%) of these 68 active spawners were cap- 
tured outside of the February-June period (Fig. 7); 
nine of the 11 fish (caught during September-January) 
exceeded median body size at female maturity (range 
550-833 mm). Adult female gonads averaged 1.35 and 
1.15% of GFBW during the February-June peak and 
throughout the year, respectively (Fig. 6). Adult male 
gonads exhibited no seasonal change in weight and 
averaged 0.23% of GFBW throughout the year (Fig. 6). 
