Crown-of-Thorns starfish
The Crown-of-Thorns starfish (Acanthaster planci) is a large and striking starfish known for its unique feeding habits and its role in coral reef ecosystems. It preys on hard, stony coral polyps and derives its name from the venomous, thorn-like spines that cover its upper surface, resembling the biblical crown of thorns. As one of the largest starfish species in the world, it boasts a wide Indo-Pacific distribution. While it is most commonly found around Australia, it also inhabits tropical and subtropical waters, from the Red Sea and the East African coast across the Indian Ocean to the Pacific Ocean, reaching as far as the west coast of Central America. Wherever coral reefs or hard coral communities thrive, this species can often be found.
The adult Crown-of-Thorns is a corallivorous predator, primarily feeding on reef coral polyps, encrusting sessile invertebrates, and even dead organic material. It uses its numerous tube feet, located in distinct ambulacral grooves on its underside, to climb over coral colonies. With its flexible body, it closely conforms to the coral's surface, including the intricate structures of branching corals. To feed, it extrudes its stomach through its mouth, spreading it over the coral's surface to a diameter matching its own. The stomach secretes digestive enzymes that break down the coral tissue, allowing the starfish to absorb the liquefied nutrients. Remarkably, a single Crown-of-Thorns starfish can consume up to six square meters of living coral reef in a year.