Translucent hitchhiker with a round mouth

[Tromni]

My nano tank is starting to mature and interesting things are starting to emerge. Some I recognize (aptaisia - sigh), and some I’ve been able to look up (cerith eggs were neat), but this one has me stumped.

it appeared at the base of a ricordia frag plug. It appears to be a translucent sack attached to the rock. But upon closer inspection, it has a round “mouth” with orange bumps surrounding the opening. If it fluoresces it’s too weak to see in my system. The “mouth” closes when my magnet scraper gets close, so it’s definitely alive.

Sorry for the potato phone pics. Hopefully someone has some ideas. Thanks in advance!

 

[Cali Reef Life]

I wanted to say a sponge but if it moves it could be white translucent colonial tunicates aka sea squirts. This a harmless filter feeder. Give it a look up online and see if it matches.

 

[WheatToast]

Looks like a Tunicate (the ability to rapidly close indicates it is not a sponge). These animals are harmless filter-feeders.

 

[Tromni]

This has to be right. I can see the “eject port” so to speak a little further back on the body. Just couldn’t find the right combo of search terms.

Thanks to you both!