Sexual reproduction in Porites divaricata (Le Sueur, 1820) was studied over a one year period (August, 2012 to August, 2013) in a shallow water (~2m depth) carbonate bank (also described as marginal) habitat at Rodriguez Key, a small island located 1.44 km off the east coast of Key Largo. Porites divaricata is a brooding, gonochoric species with peak reproductive output (planula release) occurring in March and at least a smaller event in May. This species showed an overall female to male sex ratio of 3.5:1. However, during peak reproduction, the sex ratio was 1.2:1. Spawning (sperm release) most likely occurred in late February when 78% of all oocytes and 84% of all spermaries were in stage IV of development. The largest output of stage IV eggs (n=164) occurred at this time, and these oocytes also had the second largest average individual oocyte volume (3.34x10-3 mm3, n = 79) compared to those from other sample dates. The largest average egg volume (3.79x10-3 mm3, n = 8) occurred in May, but with fewer eggs present (n=13). Population surveys showed P. divaricata densities of 7.4 and 17.7 colonies m-² at Site 1 and 2, respectively. Temperature data documented that SSTs were highly variable in the seagrass/coral habitat at site 2 (primary collection site), ranging from 13.1 to 34.9°C, with an average temperature of 25.9°C. Corals at Rodriquez Key are exposed to temperatures much higher (+3.8°C) during the summer and much lower (-8.2°C) in winter compared to corals living at a nearby bank reef (Molasses Reef). This is the first comprehensive reproductive study performed on Porites divaricata and may provide valuable information to the ongoing debate concerning the taxonomic relationships among P. divaricata, P. porites, and P. furcata.

Reproductive characters of the elliptical star coral Dichocoenia stokesi (Cnidaria: Scleractinia) were investigated based in histological examination of tissues collected in southeastern Florida between September 1999 and September 2000. The study population was predominantly gonochoric with a small incidence of hermaphroditism. Dichocoenia stokesi exhibits intermediate egg size (312.2 ± 40.4μm; mean ± SD) compared with other scleractinian species, suggesting a moderately lecithotrophic larval stage. Although spawning was not directly observed in this study, two separate spawning events per year are inferred from histological slide analyses; the first in late August or early September, and the second in early October. Sea water temperature was significantly positively correlated with female gonadal development in D. stokesi, whereas insolation was significantly inversely correlated with gonadal development. A recent epizootic of White Plague Type II in south Florida appears to be skewing local D. stokesi populations toward smaller - and potentially less fecund - colony sizes, although colony size and fecundity were not correlated in this study. The mean fecundity of the study population is estimated as 1138.1 eggs cm-2 yr-1.