Tuesday, April 27, 2010
I know most starfish have 5 arms but can they have more?
Starfish come in lots of different varieties, one recent count numbered the species in this class at about 1500! So, to answer your question, some starfish have more than five arms, in fact one, the Helicoilaster has 50 arms which all radiate from the central body part.
In addition to arms in multiples of five, many echinoderms have the remarkable ablitity to regenerate lost arms. In some cases, lost arms have been observed to regenerate a second complete sea star.