Multispecies spawning of scleractinian corals in nonreefal coral communities of northern Taiwan (northwestern Pacific Ocean)

Abstract

There is a large body of information on sexual reproduction in scleractinian corals, but regional gaps remain, especially in nonreefal coral communities. This study documented the reproductive patterns of 54 coral species in 23 genera and 8 families (41 hermaphroditic spawners, 10 gonochoric spawners, 2 hermaphroditic brooders, and 1 gonochoric brooder) in northern Taiwan by field observations and histological analysis, which indicated that they predominantly spawned in August while fewer spawned in July, September, and October. Based on the field observations, 50 species in 21 genera and 7 families spawned between 20:00 and 22:00 hrs for 5–8 consecutive nights after the full moon in July and August from 2013 to 2016. The spawning patterns varied profoundly in species and colony number from 2014 to 2016: 19 species (42 colonies) in 2014, 6 species (20 colonies) in 2015, and 33 species (120 colonies) in 2016. Most merulinid and lobophyllid corals were observed to spawn consistently over the three years, particularly Favites pentagona, and corals splitly spawned within the colony. Five coral species spawned bimonthly. Three brooding corals (Pocillopora damicornis, Stylophora pistillata, and Porites lichen) also sexually reproduced between summer and early fall. Through this study, we obtained a better understanding of spatial and temporal patterns of the sexual reproduction of corals in nonreefal coral communities. Furthermore, this research may have broader biogeological implications for the northwestern Pacific Ocean region.