Saw what i think is a starfish this morning but it only has 4 arms... I dont think its asterina.. any ideas.. thanks. oh its about the size of my thumbnail.
Asterina can have 3, 4, 6 or more arms. They may or may not be a problem, depending on which species it is (I don't think they can be identified to species).
Asterina rip themselves into pieces to multiply, with each piece (as small as one arm with part of the central disk) growing new arms to become a full star.