Hitchhiker ID red tentacles

[TimHazekamp]

I have no idea what this tentacle like Hydra type creature is on the glass of my QT. Been on there a few weeks. It crawls around very slowly. I have another smaller one further down, and have seen before on the sandbed surface of my display tank before too. This one is maybe 1/2 inch long. Anyone have any idea if it is ok to leave it be?

 

[Josh_boss]

Wow! I’m curious too! It’s actually really nice, but scary if you don’t know what it’s capable of. I’ll wait for some answers

 

[jeffchapok]

If you hadn't said it was moving, I would have said it's a sponge. But I'm not aware of any sponge that moves.

 

[35ppt]

Redacted

 

[TimHazekamp]

Foraminiferan, very cool! Feeds on bacteria and other small particulate material.

I've not heard of that one before. Interesting, sounds safe to leave alone.