It was a first for us to actually witness a giant triton feeding on a Crown of Thorns at our Yadua Pinnacles dive site!
(Photograph courtesy of guest Gary Pile from the UK)
Some interesting information on the Crown of Thorns starfish and giant triton snail........
The crown of thorns starfish (COTS) Acanthaster planci is known for its incredible appetite for feeding on the flesh of live corals leaving white, dead coral skeletons behind it. COTS are a natural part of the ecosystem and COTS outbreaks are both good and bad. But how so?
Good only when the outbreak takes places at a gap of around 15 years. They just infest the areas and feed on the corals that grow faster and provide the opportunity for the slow-growing corals to regenerate. This allows proper balance. The problem occurs when these outbreaks happen in quick successions (that is, in less than 15 years). Since the corals do not get ample time to regenerate, coral reefs become endangered.
To make the situation even harder for the coral reefs, other factors like coral bleaching and cyclones occur. These factors are also known for destroying and killing the corals and make food supply short for the Crown of Thorns Starfish. For instance, the Staghorn Corals are their primary food source. However, when the food source is wiped out by these other factors, the COT start feeding on other corals which are not so fast growing. This creates a massive threat for the coral reefs.
The giant triton (Charonia tritonis) is named after the Greek god Triton (son of Poseidon and god of the sea). Due to the beauty of their shell, the giant triton has long been harvested from coral reefs, primarily for sale to shell collectors leaving a shortage of them in our seas. Their preference for feeding on COTS is well known.
COTS have a particularly well developed sense of smell and there is nothing more alarming to a COTS then the scent of a giant triton. Equally, there are few things more enticing for a giant triton than the scent of a COTS. Once detected, a COTS will be purposefully hunted down and devoured by a hungry giant triton.
Here at Deep Blue when we notice an unusually large amount of COTS on our snorkel or dive sites, we have clean ups to try and help save our coral reefs.