• If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • You already know Dokkio is an AI-powered assistant to organize & manage your digital files & messages. Very soon, Dokkio will support Outlook as well as One Drive. Check it out today!


Crown-of-Thorns Seastar

Page history last edited by Blythe 10 years, 8 months ago

 Crown of Thorns Seastar

Blythe M


The Acanthaster planci, also known as the Crown on Thornes Seastar is a kind of dangerous starfish. It is know for eating coral, preferably the Coral Polyp. Commonly found in the Indian and Pacific Oceans this Seastar can grow up to 80 cm with up to 21 arms, and a typical Starfish only has 5-7 arms. This starfish has pointy venomous spikes that with one touch can seriously harm any human or sea creature. Varying in colors, it can be grey and green with some red but in the warmer oceans some species can be bright blue or purple. The Crown of Thorns Seastar is in the Echinoderm classification.


 1. 2.3.



The Crown of Thorns Seastar lives on the Great Barrier Reef. The reef is home to its main diet of coral. It also gives the Seastar shelter and protects them when they are young. There are over 400 different species of coral living on this reef. The Crown of Thorns Seastar is only one of the 1500 different species living on this reef. These species include, the Tiger Shark, Angelfish ButterflyfishSeahorse and the Sea Anemone


Great Barrier Reef:



Predator Adaptations:

The Crown of Thorns Seastar hunt using there sense of smell because they dont have eyes. Once a smell that they wish to hunt is detected, the seastar brings itself over to the smell (commonly the Coral Polyp). Since the seastars mouth is on the oral surface or the underside of their body, the Crown of Thornes covers the prey by pushing out its stomach from inside its body. Once the seastars stomach has made the prey into a gooey liquid, the liquid is slowly devoured into its body. 


Prey Adaptations:

The Crown of Thorns Seastar is prey to Giant Triton Snails, Painted-Prawns, Green Triggerfish and the Napoleon wrasse. Predators arent such a threat to the seastar due to its spikey body.



Symbiotic Interactions :

The symbiotic interactions for the Crown of Thorns Seastar is parasitism. When the seastar smells food that they wish to eat they harm the coral so the coral gets harmed but the seastar gets a meal. 


Similar Species: Blue Linckia Sea Star


Both seastars live on the Great Barrier Reef and both sea stars can turn to a bright blue color. 



The blue seastar eats meat such as clam mean while the crown of thornes seastar only eats coral. 






"Crown of Thorns." Crown of Thorns.

ReefED, n.d. web May 2013.


2.Crown-of-Thorns Starfish. Photograph.

 Encyclopædia Britannica Image Quest. 

Web. 23 May 2013.http://quest.eb.com/images/139_1902006

3.Crown-of-thorns Starfish, Acanthaster Planci, New Caledonia. Photograph. 

Encyclopædia Britannica Image Quest. Web. 23 May 2013.


4. Crown-of-thorns Starfish, Acanthaster Planci, New Caledonia. Photograph. 

Encyclopædia Britannica Image Quest. Web. 23 May 2013.


5. Great Barrier Reef. Photography. 

Encyclopædia Britannica Image Quest. Web. 23 May 2013


6. Information for Predator Adaptations: 

John G "Crown of Thornes Sea Star" Shedd (the World's Aquarium)  John G 2013 n.d. web May 29 2013

7. Prey Adaptations Information and symbiotic interactions and similarities and differences information

Haley Davis (Lead Author);John Bruno (Topic Editor) "Crown-of-thorn sea star". In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth January 19, 2008; Last revised Date September 20, 2010; Retrieved May 29, 2013 <http://www.eoearth.org/article/Crown-of-thorn_sea_star?topic=49513>













Comments (0)

You don't have permission to comment on this page.