Bob and Darren are right on the money-get rid of those suckers or they will give you trouble! Double trouble! Triple............. and so on.........
I have seen chocolate chip stars that consume these little guys no problem. If you know someone who has a CC starfish, see if you could rent it from them for a couple of days
All you have to do is place the star right ontop of the majano, and the next day-bam! all gone
cheers, Rich