James Guest is currently persuing a PhD, working on reproduction of corals.

Mass synchronous spawning is a remarkable phenomenon that is unique to marine invertebrates. There are very few reports of mass coral spawning from low latitude reefs and it has been suggested that this phenomenon may be absent or significantly reduced close to the equator. Sampling of the coral genus Acropora to determine their reproductive state was conducted at the southern most reef off Singapore (Pulau Satumu, 1° 10'N 103° 45'E), on March 21st 2002 (eight days before the full moon).

From 22 different Acropora species, 15 (68%) had at least one colony with mature eggs, 48.5 % of colonies had mature eggs (pigmented), 10 % had immature eggs (un-pigmented), and the remaining 41.5 % had no visible eggs (n=112). On the 3rd, 4th and 5th nights after the full moon between 8 and 10pm we observed synchronous spawning of corals. At least 18 different coral species from 10 genera and 5 families were observed releasing gametes over the three nights. This is the first time multi-specific spawning of corals has been observed in Singapore. These observations demonstrate that this phenomenon can indeed be a characteristic of equatorial coral reefs.