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Fishery Bulletin 115(2) 
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Figure 4 
Total numbers of courtship-associated sounds (CASs) produced by black grouper 
{Mycteroperca bonaci) per hour summed during entire deployment at 3 spawning 
sites: (A) Riley’s Hump off southern Florida and, in Puerto Rico, (B) Bajo de Sico 
and (C) Mona Island. Hourly totals are summed from days of increased spawn¬ 
ing activity. All times are in local Atlantic Standard Time (-4GMT). 
temperatures are a seasonal controlling factor for the 
formation of spawning aggregations of black grouper. 
The CAS rate increased significantly between the 
last quarter moon and the new moon at all 3 sites (Fig. 
3). Between the last quarter and new moon, moonrise 
occurs after sunset. Furthermore, during these lunar 
stages, CAS production peaked during late afternoon 
hours (Fig. 4). More than half of ail CASs produced 
over the 3 years at Mona Island occurred within a 2-h 
period around sunset. At Riley’s Hump, almost half 
