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Crown-of-thorns starfish (COTS for short) feed on coral. These spiky marine creatures occur naturally on reefs in the Indo Pacific region, including the Great Barrier Reef.

In normal numbers on healthy coral reefs, COTS are an important part of the ecosystem. They tend to eat the faster growing corals which gives the slower growing species a chance to catch up, enhancing the coral diversity of our reefs.

However, when the coral-eating starfish appear in outbreak proportions, the impact on coral reefs can be disastrous.

As part of the Tourism Industry Activation and Reef Protection Initiative, Red Cat Adventures has been awarded a permit to help eradicate any COTS that are found while doing the Reef Health Impact Surveys.



COTS are nocturnal by nature, and they can move at speeds of up to 20 metres an hour!

COTS prey on nearly all corals, and can eat their way through 10 square metres of it a year.

The COTS spikes or spines contain toxins that are poisonous to both humans and marine creatures.

It’s the world’s second largest starfish, reaching up to 1m!

They eat their coral prey by extruding their stomachs out from their bodies, covering the corals.

Like most starfish, if it loses one of its arms, a COTS can regrow a new one in around six months.

An adult Crown of Thorns Starfish can live up to 9 months without eating!



Master Reef Guide Cam Butler with the Crown of Thorns Starfish removed on a recent Reef Health Impact Survey trip

Above: Image courtesy of Living Oceans Foundation

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