Crown of Thorns Starfish Information

Crown of thorn starfish (Acanthaster planci ) are coral-eating starfish located in and around the Pacific Ocean. Though potentially invasive and detrimental to coral populations, crown of thorns starfish help maintain coral reef balance, keeping fast-growing coral in check.

Shape

Crown of thorns starfish have a central disk to which seven to 23 arms are attached. The arms have 2-inch long poisonous spines, set on the starfish's aboral side (the side opposite its mouth). Crown of thorn starfish can grow to approximately 20 inches across.

Coloration

Crown of thorn starfish's coloring ranges from yellow spines and a green body to a purple-blue body with red tipped spines. Coloration tendencies depending on location have been noted.

Feeding Habits

Smaller crown of thorns starfish (8 inches across or less) usually feed at night while larger crown of thorns starfish (larger than 15.75 inches across) usually feed during the day.

Reproduction

Crown of thorn starfish are either male or female and reproduce once a year during midsummer. The starfish release sperm or eggs into the water via their central disk.

Location

Crown of thorns starfish span from the west coast of America to the western part of the Indian Ocean. They can also be found in the Red Sea.

Consideration

The wounds that the crown of thorns starfish causes with its spines are slow healing and painful.

References

• CRC Reef Research Centre: Starfish on the Great Barrier Reef
• University of Salzburg: Acanthaster Planci
• Invasive Species Specialist Group: Global Invasive Species Data List