About snails eating starfish and starfish eating coral?

Question

A friend was telling me about a starfish that is detsroying the great barrier reef because the snails that eat the starfish have been overcollected foir food. Is this right? I didn't think snails ate starfish.

Answer 1

Your friend is correct. The starfish in question is a large spiny species called the Crown of Thorns (Acanthaster planci). It can reach 3 feet in diameter. Most snails don't eat starfish, but one does, namely the Pacific Triton (Charonia tritonis). It would be bad enough if these large snails actually were overcollected for food. But that is not the case. They have been overcollected primarily for their large and beautiful shells, which are sold in gift shops and tourist shops all over the world, as decorative items. The species is now protected in many areas, including the Great Barrier Reef, and is now making a successful comeback.

Here’s a pic of the Crown of Thorns:

http://ryanphotographic.com/images/JPEGS/Acanthaster%20planci%20Crown-of-thorns.jpg

Here’s the living snail attacking a Crown of Thorns:

http://members.cox.net/arniesdca/shells/charoniaOnCrownofTh.jpg

And here’s a picture of the triton shell:

http://www.conchking.com/Pacific%20Trtons.jpg

.

Answer 2

I haven't heard that. But we are raping the sea of it's coral at a fast rate. So maybe they are turning to other food sourse.