What are these red threads looking stuff grown on my zoas?

[Mightyfish]

Noticed fair a bit of these red threads looking stuff growing on my zoas. Does anyone know what it is? Do they cause any damage?

 

[Puffyluv]

Not sure of the name of this algae...have seen it before, though. It can get out of control...but it doesn't look as if it is bothering those particular zoas any more than the sponges growing around them...

If your tank is too small for a tang, I believe that mexican turbos eat it, probably emerald crabs, too.

 

[lhm nole]

Better be careful it can grow rapidly and choke out lights to your zoas lucky for me all my tangs eat it .. Have bought a few colonies covered in it and in less than 24 hours my tangs have eaten it all

 

[Piper27]

Looks like red turf algae, get a few Mexican turbo snails and show them the affected spot. They will mow it down in no time.