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Name: K Omogo
Status: Student
Grade:  9-12
Location: IL
Country: United States
Date: July 2008


Question:
My science book states that a cut up starfish can regrow into more starfish. I want more information. Can an arm regenerate a whole new starfish? I have trouble believing this.



Replies:
Starfish, also known as sea stars, (they are not fish) are capable of regenerating even one arm into a whole new body. This is only possible if the arm includes part of the central disc. If you cut off only the tip of an arm, that tip will not regenerate, but the animal will grow another arm. I have seen a single arm nearly 8 inches long with small 1/2 inch arms growing off of it, it will eventually become a whole new sea star. If you cut a sea star in quarters, right down the center, each piece will grow into a whole new sea star. I do not know how many pieces one can cut any one starfish into and still have each regenerate. As long as a piece has part of the central disk, it should regenerate into a whole organism. But if you cut a starfish in half, and then let it grow into an whole one before cutting it in half again, one should be able to do that indefinitely.

Jim Murray



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