Rock Hitchhikers...good or bad?

Any ideas? We are new to this...so far things are going well, but I've got a coupla hitchhikers on the live rock and not sure if good or bad. See photos. The critter with the polyp-like head has three or four buddies on the same rock. The white (pineapple sponge??) thing is solo...his buddy disappeared recently.

 

their button polyps, good coral hitchhikers

 

+1 to above post. Some kind of zoa or button polyps. Congrats on the good hikers!

 

i have the same button polyps and they get bout the size of a quater

 

yeah dont worry bout those hitch hikers. IMO if you want to be safe of hitch-hikers such as pistol or mantis shrimp put the LR in saltwater and raise the salinity all the way to that of completely unnatural salt, maybe about 1.032-1.040 or whatever the hell you can raise it to so the inverts or bad hitchhikers can die

 

More pics of hitchhikers...

Hi guys...I got some better pics of the polyps. I know they are button polyps, but I'm wondering if anyone can give me a more specific ID. Also, I've noticed this reddish "stalk" right near the largest of the button polyps. It appears to be growing to me...you can see it in a couple of these pics...any ideas on that?

Thanks again!!!

 

The reddish stalk is a vermitid snail. Harmless but can be a pest. Best ID is Protopalythoa sp.

 

@2in10...a snail that doesn't move? It's been in the same spot for days...hadn't moved even a mm. Thanks for the ID on the polyps.

 

Yes, they send out mucus streamers to capture food and then reel them in.

 

Aaaaah...thanks...as a matter of fact I had a pic that seemed to show one of these streamers. I didn't know what it was.