fan worm

Hi everyone! I recently noticed a fan worm hitchhiker attached to the back of my trochus snail. It’s built a little sand tube, and while I’m happy to have a free fan worm, I’m concerned that if it keeps growing, it might start affecting the snail’s ability to move around and eat. Has anyone...

found this little thing on my aussie live rock i’m curing and have no clue what it is but it looks super cool (it’s tiny)