Spawning spectacle

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Every year in September and October, about 5 to 7 days after the full moon, during the evening hours the Caribbean sea fills up with billions of reproductive cells produced by the reef building corals that make our reefs so special. This spectacular process is one of the wonders of the natural world. Only recently, scientists have been able to unravel a fraction of the mystery behind ‘the ways of the corals’. During such a spawning event, fertilization of the eggs take place within the ‘reproductive soup’. After a while, free swimming larvae will emerge from the eggs in a search for the perfect spot to colonize. When this spot has been identified, a larva will cement itself to the chosen substrate, after which a-sexual reproduction (cloning) will become the driving factor behind the construction of the multi-chambered coral colonies our reefs are well known for. Unfortunately, scientists are alarmed by the fact that the success of settlement has gone down dramatically over the last two decades. The reason? Mostly nutrient enrichment of coastal waters (from human waste), inducing excess growth of algae.

The first video shows the spawning behavior of the boulder star coral (Montastrea annularis), the second is of the massive starlet coral (Siderastrea siderea) and the third of the great star coral (Montastrea cavernosa). The videos have no audio track.

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