Something growing out of rock?

[Austin Weinerman]

So these little things have been on my live rock ever since I set my tank up about 3 months ago. They used to be completely brown with what looked like a little hair on top (obviously it wasn’t, I don’t know the proper name for these little fuzzy things). Recently, every single one in my tank has turned green and the little “fuzzy things” have developed into what looks like a polyp? It looks like I can even see a mouth on each one. My cleaner shrimp, hermit crabs, and snails crawl over them all the time and never seem to be bothered, but I am still curious about what they could be. Any thoughts?

 

[Mikedawg]

Palythoa zoanthids; be careful if you handle them - some degree of toxicity.

 

[Austin Weinerman]

Palythoa zoanthids; be careful if you handle them - some degree of toxicity.

Hmm, weird that they started growing out of no where. Or maybe it’s not as unusual as I think it is, haha. Thank you.

 

[KJ]

Colonial hydroids.

 

[cloak]

Colonial hydroids.

+1

 

[TheEngineer]

Colonial hydroids.

+2. Take the rock out if you can. They spread and are a pain to eradicate.

 

[Austin Weinerman]

Thank you everyone. After looking up pictures of green hydroids, I agree it is definitely that.

+2. Take the rock out if you can. They spread and are a pain to eradicate.

Unfortunately, they are on just about every piece of rock in my tank. Besides not looking too great, is there any risk in having them in my tank?

 

[Dalmatia]

....

 

[TheEngineer]

Best advice I can give you is this thread;

https://www.reef2reef.com/threads/here-it-is-fenbendazole-use-against-hydroids.214950/

 

[Mikedawg]

Yeah, more I look at your pick + 1 on hydroids. Some reefers use super glue to cover them up, inject with boiling water or lime juice, etc. Pretty much what they use to control aiptasia.

Good luck.