Some marine species, such as broadcast spawners, coordinate the release of gametes on the full moon or a fixed number of days after it.

Judge as of 2025-09-24 against the scientific literature. True: peer-reviewed studies show that some marine species (e.g. reef-building corals or other broadcast spawners) time their mass gamete release by the lunar cycle, at or a fixed number of days after the full moon. Mostly true: lunar timing of spawning is well documented, but the usual cue is a different lunar phase or a combination of lunar and other cues, so 'on the full moon' is a small simplification. Mixed: the evidence ties spawning to the moon for only a few species, or the link is disputed. Mostly false: spawning is synchronised but the evidence shows the moon plays only a minor or unproven role. False: studies show no lunar timing of spawning in marine species.

Set before the research began.

1. E1 Synchronous spawnings of 105 scleractinian coral species on the Great Barrier Reef James Cook University ResearchOnline (article in Marine Biology, Babcock, R.C. et al.) · 1986

   “The mass spawning of corals took place on only a few nights of the year, between the full and lastquarter moon in late spring.”

2. E2 Synchronous spawnings of 105 scleractinian coral species on the Great Barrier Reef James Cook University ResearchOnline (article in Marine Biology, Babcock, R.C. et al.) · 1986

   “Lunar and diel cycles may provide cues for the synchronization of gamete release in these species.”

3. E3 Coral mass spawning predicted by rapid seasonal rise in ocean temperature - PMC PubMed Central (article in Proceedings of the Royal Society B, Keith, S.A. et al.) · 11 May 2016

   “over 130 species spawn in the week following the full moon in October or November”

4. E4 Coral mass spawning predicted by rapid seasonal rise in ocean temperature - PMC PubMed Central (article in Proceedings of the Royal Society B, Keith, S.A. et al.) · 11 May 2016

   “The most common hypothesis for corals states that environmental cues work at progressively finer scales to regulate: (i) the month of spawning, (ii) night of spawning (lunar cues, [20]) and (iii) the time of spawning (sunset)”

Peer-reviewed studies record lunar timing of coral mass spawning. On the Great Barrier Reef, spawning took place on a few nights between the full moon and the last-quarter moon (E1), and a 2016 paper reports over 130 species spawning in the week after the October or November full moon (E3). The same papers describe lunar and daily cycles as possible cues (E2), and the most common hypothesis has lunar cues setting the night, with other cues setting the month and the time of spawning (E4). So the evidence clearly supports lunar coordination. Spawning is reported in the days after the full moon, which Pinker allowed for; the papers describe the moon as one of several possible cues, so "on the full moon" is a slight simplification.