Species Index

Acanthaster planci
(Linnaeus, 1758)

Common Name: Crown Of Thorns Starfish

Distribution: Relatively uncommon in the Solitary Islands Marine Park. Distributed across the Indo-Pacific, east Mexico and Galapagos Islands, India in the west. In Australia most records from the Queensland east coast and the Exmouth region of Western Australia.

Ecological Notes: Found wherever scleractinean corals are abundant. Sometimes reaches plague proportions and has been responsible for widespread decimation of corals in the Great Barrier Reef. Depth to at least 65 m.

Additional Notes: A voracious predator, feeding scars (whitened coral skeletons, top right in top photograph), often found in vicinity. Avoids sand and mud as the tube feet are unable to grip a soft subtrate and in areas of high water movement, sand can provide a barrier to movement between reef patches. Larvae feed on phytoplankton, and once developed into juvenile starfish they feed on encrusting algae. The starfish feeds on polyps of corals by everting its stomach and secreting enzymes and is referred to as a “corallivore”. A single starfish can graze ten square metres of coral yearly. Preferred coral species in the western Pacific include Acroporidae and Pocilliporidae families. Juvenile approximately 150 mm wide in bottom photograph. Sharp spines may cause painful wound. Grows to 550 – 600 mm.

References: CABI, 2018 Acanthaster planci. In: Invasive Species Compendium. Wallingford, UK: CAB International.