Is this some kind of star fish?

I bought a peppermint shrimp and 3 blue leg hermit crabs and I think this little guy hitchhiked in with them! is it a starfish of some kind because I was planning on buying one anyway!

ps sorry for the pic but the lights weren't on yet and he has since disappeared!

 

Asterina: Many different types. Some can be an issue secondary to excess population growth. A few among the bunch eat corals. I usually keep them until they prove me wrong.

 

I have them and they never bother anything. I had a chocolate chip starfish for a while in my reef tank and it left my corals alone but ate most of those asterina starfish

 

Thank you for the info! I just found an old thread on here telling how they eat coral so im a lil worried now ! any natural predators safe for reefs that you can reccomend ?

 

What are you hoping for the predators to eat?

Hermits are predatory when the need, or a handy meal arises (they're opportunistic omnivores), and while peps really aren't predatory, they will indeed finish off dying critters.

 

There are many types of Asternia, most are harmless algae eaters, some prefer coralline algae. I would not worry about one Asternia, nor would I buy one type of critter with the hopes that it will eat another most likely harmless critter.
A lot of harmless hitch hikers will pop up as your tank becomes established, fretting over them is pointless.