Common Sea Star

Common Sea Star
Asterias forbesi

common vs northern sea star

The above picture depicts two types of sea stars that are common to tide pools in New England and Atlantic Canada.  The one on the left that is circled is the common sea star.  The one on the right is the Northern Sea Star.  The easiest way to tell the difference is the orange “dot” on the top of the common sea star.  The Northern Sea Star also has this dot, but it is more of a pale yellow color.    This dot is the madreporite, a structure used to regulate the amount of water coming into their water vascular system that powers all the tube feet on the other side.

common sea stay madreporite common sea star tube feet

Where to Find Sea Stars: docks, rocks, and by themselves in a sandy tide pool between sand flats.

common sea star 1
A common sea star in a tide pool between the sand flats in the Northumberland Strait. (Nova Scotia) (August 1st, 2013)

common sea star 2

Leave a Reply

Your email address will not be published. Required fields are marked *


Biodiversity Exposed