Found this guy the other day swaying in the current. I gave him a piece of brine shrimp to see if there was a reaction and it appears to be trying to eat it. The owner of my LFS who is also an active Biologist said he hasn't seen anything like it.
There is also a video of it here:
https://www.youtube.com/watch?v=d285iBzP2J4
It's pretty small currently but seems to be able to contract it's size based on the video. If I had to guess I would say it's around 1/2 - 3/4". It also hasn't moved since I noticed it so I'm assuming it's not very mobile like a traditional worm (if it is a worm at all).
There is also a video of it here:
https://www.youtube.com/watch?v=d285iBzP2J4
It's pretty small currently but seems to be able to contract it's size based on the video. If I had to guess I would say it's around 1/2 - 3/4". It also hasn't moved since I noticed it so I'm assuming it's not very mobile like a traditional worm (if it is a worm at all).