Is this a starfish and reef safe?

[Gore15]

Hi. I picked some live rocks and there are two being similar to this and a l0 cm long many legged brown worm. 
 

I am wondering if this is a starfish of some sort and safe to put into my tank?

 

thank you. 

[jambon]

Brittle starfish and a great addition.. they hide most of the time cleaning up detritus and uneaten food... 

[Gore15]

Thank you. I let it into the tank and it went directly to the hideout of the pistol shrimp. Now it is disappeared completely. I have a bad feeling about it.

 

There was another ?starfish? more or less similar to this one but in white color. I saw it once and didnt manage to catch it. I hope it is another ok sea faring addition to the tank.

 

Also there was this very very tiny snail which I let it into the tank as well (I have a nano tank). I assumed that it is tiny and it is a snail so it is safe to let it in.

[Tired]

Those are both micro brittle stars. The striped one is sometimes called a "black" micro brittle, even though it's striped. They get about 2-3" across, including the legs. They may breed in your tank, and are great scavengers, completely harmless to life in your tank. You'll see them reach their arms out if they smell food. 

 

White micro brittle stars stay about 1.5" across, and will definitely breed in your tank. They're great scavengers as well, with the same habits. You want both of them in! They're good guys. Tiny scavengers great at getting into crevices and eating detritus. 

 

The snail was probably something harmless, but in future, it's best to get a picture of snails and ask what they are. There are a few harmful varieties. Wild guess: look up collonista snails and see if they match. 

[Gore15]

I hope I have not invited an invasive snail into my tank. Will see if I can spot it and then make photos and keep it in plastic bag. And thank you very much for being so quick in helping.

[Tired]

You're welcome. If you spot the snail again, you can put it in a cup of tank water, set the cup away from the tank, and get a picture for an ID. Don't float the cup (or a bag) with the snail in the tank, as it may crawl out and back into the tank. I had a flatworm I had captured do that. 

 

The snail is probably harmless, but it's good to be sure. If it's a collonista snail like I'm guessing, it's completely harmless. They don't do much for the tank because they're so small, but they multiply and will remain present, and I personally like them. I like the patterns.