Asterina's eating coraline!?!

So i noticed some asterina in my tank a few months ago and read up on them.Since then i havnt noticed any on my corals so wasnt worried.
Last week i noticed one sitting in the middle of a spot of coraline on the glass.It has since moved away but left dead white spots on my coraline.
Are these things constantly killing coraline that they sit on?

 

Some eat coralline and some eat whatever they get off your rocks.

 

I have read that they can eat coraline. I have a ton in my tank and have a never ending supply of coraline, so I haven't noticed an issue.

 

You need a ton of them to make a dent in your coralline.

 

Thanks guys.I guess i just wasnt expecting it.Does anyone manually remove these guys and if so how do you go about it.I was thinking Loong tweezers...

 

If you want to remove them that could be an effective way.

 

But they are so cute!! They one of my favorite things in my tank!

 

Wait till you have thousands of them, they are not so cute then.

I have harvested mine by the hundreds every so often. Can't stand it anymore. I've been trying to get a Harlequin locally, but no one has one.

Never knew they ate coraline. That would make a lot of sense. Mine started dying off with white spots. Don't really care cause I don't really want to scrape coraline all the time either.

 

I occasionally see mine do this. I also see them crawling over coral bases. never hurt anything.

 

The store down on East Hampden usually has harlequins in stock.