7 arm starfish id?

[ezhoops]

Well I wish I had a picture of it but its about 1/2inch in size and its completely white. Should I be concerned, I have a reef tank? Its not a stringy arm (brittle star type) its got a thick body with thick arms.

 

[SushiGirl]

Likely an asterina star.

 

[ezhoops]

is that good

 

[jayelblock]

Well, that depends. They reproduce very quickly by splitting, so you can have a tank full in very short order. While they don't eat coral for the most part (although some types do if they get hungry enough according to this article), they can irritate your corals if they cover them in great enough numbers. Also, they do eat coralline algae, which some people find to be a negative aspect.

I've got a bunch in my 10g, and I find them amusing. Some have 4 arms, some have more, and I enjoy looking at them. Having said that, I've got a few more than I care for, so I've made arrangements to borrow a pair of harlequin shrimp from my LFS if they get too much more out of hand.