I can attest to just about his entire statement as I have one of each in my tank :o)
My Linkia star is a good algae eater.. however I did just catch him stripping some newly purchased Culerpa right to the stem!
I have a banded serpent star that is rarely seen... other than his legs that is. He's a great comic relief in the tank... I always see just his legs sticking out from under the LR
, like it was dropped on him in a cartoon!
I also have a long spine sea urchin.. he's huge! His body is about 3 inches in diameter but his spines give him an over all 9-10 inch diameter... He does eat a lot of algae which is good but he does take up a lot of space in the tank as well as feasts regularly on my Culerpa... I've had some here mention they can be tough on anenomes and corals as their spines can ofter inadvertantly puncture the anenomes and corals. I think i'll be getting rid of him soon... which does sadden me he was one of the first inhabitants of my tank... Spike, is his name... Spike is just neat :o(