What's this tube creature?

[lowwall]

Seen in the shallows at Blue Heron Bridge on Christmas Eve. It's around 1.5 ft/.5m long.

Also there's a 2 second video of it moving at https://photos.app.goo.gl/BhZXbpew2xPHdLo79

 

[tursiops]

Looks like a Ribbon Worm.

 

[lowwall]

Thanks. I guess it had just swallowed something big.

 

[ThatDogDontHunt]

Could it be a Beaded Sea Cucumber?

They look very different squished up vs stretched out.

 

[cgills]

Thinking perhaps a Phylum Sipuncula or Peanut Worm..given length and longitude lines?

 

[tursiops]

Thinking perhaps a Phylum Sipuncula or Peanut Worm..given length and longitude lines?

I could find no species registry that mentioned peanut worms longer than 20cm.

 

[lowwall]

It was definitely in the 1-2' range. We watched it for a full minute from a few feet away. The instructor (my son was doing his OW class) didn't have any idea what it was.

 

[cgills]

I could find no species registry that mentioned peanut worms longer than 20cm.

Tha'ts true Ribbon worms definitely longer, but body shape generally flatter as well/? At least those I have observed diving .

 

[tursiops]

Tha'ts true Ribbon worms definitely longer, but body shape generally flatter as well/? At least those I have observed diving .

Here is a page from Humann, Deloach, Wilk: Reef Creature ID, Tropical Western Atlantic, showing some unidentified ribbon worms. I don't think they are always flat!

 

[lowwall]

I think it had just eaten something which could account for the shape. It was writhing around and contracting and expanding body segments. Looked like a special effect from a horror movie.