Echinodermata · echinoderms

Crown-of-thorns starfish

Acanthaster planci

Acanthasteridae · crown-of-thorns starsIUCN: Not evaluated
Crown-of-thorns starfish
Photo: John Hepburn · CC BY 4.0 · Wikimedia Commons · resized

A venomous, many-armed sea star that eats living coral.

Fun factIts outbreaks have destroyed large areas of the Great Barrier Reef.

Waters
Indo-Pacific
Depth zone
Coral reefs
Diet
Coral polyps
Size
Up to 80 cm

Classification

Echinodermata › Asteroidea › Acanthasteridae

  1. Kingdom Animalia animals
    • Many-celled organisms that eat other living things for energy (heterotrophs)
    • Cells have no cell walls
    • Most can move at some stage of life
  2. Clade Bilateria bilateral animals
    • Body has a left and right side that mirror each other (bilateral symmetry)
    • Head end with concentrated nerves; three tissue layers
    • Includes about 99% of all living animal species
  3. Clade Deuterostomia deuterostomes
    • In the embryo, the first opening becomes the anus and the mouth forms second
    • Includes echinoderms and chordates
  4. Phylum Echinodermata echinoderms
    • Adults usually have five-part radial symmetry
    • Water-vascular system powers tiny tube feet
    • Skeleton of limestone plates (ossicles) in the skin
  5. Class Asteroidea sea stars
    • Sea stars: usually five or more arms joined broadly to a central disc
    • Tube feet on the underside of each arm
    • Many push their stomach out to digest prey
  6. Family Acanthasteridae crown-of-thorns stars
    • Crown-of-thorns stars: many arms covered in venomous spines
    • Feed on live coral
  7. Genus Acanthaster
    • Species in the same genus are very close relatives and often look alike.
  8. Species Acanthaster planci Crown-of-thorns starfish

Closest relatives in the guide