Spots on live rock??

[emeraldeyes_bc]

I just got this live rock from the LFS and it has these bright green spots. Should I be concerned? Is it bad for my tank? (Hopefully you can see it)

It also came with a little brown furry crab... From what I understand this is a bad guy yes??

 

[emeraldeyes_bc]

And the red too, here's a better picture of the red (sorry, i'm a newb and soooooo afraid to introduce something bad)

And do I need to do anything to them before I put them in??? (The tank is 3 days into cycle, nothing live yet)

 

[glb]

I'm not sure what that is. I thought sponge at first but when I zoomed in I saw that they had little branches. Hopefully someone with more experience will be able to id it.


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12g Nanoreef. Zooanthids, Ricordia, Star Polyps and two clownfish. CF Lighting, 75% actinic blue, 25% 10,000k white.

 

[emeraldeyes_bc]

Yes, they definitely have little branches or arms.

And I managed to get the crab out of the rock. This is a bad guy to have right?? Brown, hairy, and black claw tips?? (Gorilla crab??)

 

[Mike J.]

Does the crab have cupped claws? If yes, it is a Mithrax crab and it is a good guy. The red things are foraminiferans and they are very good. The green stuff I can't see - probably algae.

 

[Mike J.]

Does your crab has claws like this? This is a shed of a crab I have in my reef. Actually I have two of them and they have never bothered anything. And, they keep the bubble algae completely under control.

IMO they are very good crabs.