Curious what this worm is?

[Tub Life]

Saw this on the glass, lights were off. It looked like a thin grey earthworm.

Scooped it out and not quite sure what it is. Doesn't look like the bristleworms I've dealt with iver the past decades.

 

[Tub Life]

 

[ISpeakForTheSeas]

Saw this on the glass, lights were off. It looked like a thin grey earthworm.

Scooped it out and not quite sure what it is. Doesn't look like the bristleworms I've dealt with iver the past decades.

This one's probably not a keeper - it's either an Oenonid worm or a Lumbrinerid worm.

For Oenonid worms:

these worms tend to feed on mollusks (bivalves - clams, oysters, mussels, etc. - and snails)

For Lumbrinerid worms:

To quote about their diet:
"most lumbrinerids are carnivores on both sessile and motile prey, with a few herbivorous and subsurface deposit-feeding exceptions"*

The carnivorous ones tend to eat things like bivalves, snails, other worms, brittle starfish, and occasionally Heart Urchins (Spatangoida). The herbivorous ones feed on diatoms, sea grass, etc.

*Source:
Diet of Worms Emended: An Update of Polychaete Feeding Guilds - Appendix A - Family-by-Family Review
(The paper)
https://www.annualreviews.org/content/journals/10.1146/annurev-marine-010814-020007 (The link you can download the Appendix from)

Diet of Worms Emended: An Update of Polychaete Feeding Guilds | Annual Reviews

Polychaetes are common in most marine habitats and dominate many infaunal communities. Functional guild classification based on taxonomic identity and morphology has linked community structure to ecological function. The functional guilds now include osmotrophic siboglinids as well as...

www.annualreviews.org

For your specific worm:
I don't see a peristomial notch or any eyespots on the ventral (underside) of the head, so the other thing I can think to ask is: does it have three little tentacles tucked up under the ring of flesh right behind its four eyes on the top of its head?

If so, I expect microscope pics of the bristles would reveal both normal bristles as well as hooded hooks, and that would mean this worm is Oenone fulgida.

 

[Tub Life]

This one's probably not a keeper - it's either an Oenonid worm or a Lumbrinerid worm.

For Oenonid worms:

For Lumbrinerid worms:


For your specific worm:
I don't see a peristomial notch or any eyespots on the ventral (underside) of the head, so the other thing I can think to ask is: does it have three little tentacles tucked up under the ring of flesh right behind its four eyes on the top of its head?

If so, I expect microscope pics of the bristles would reveal both normal bristles as well as hooded hooks, and that would mean this worm is Oenone fulgida.

I did not see any tentacles near its head.
My Ritteri ate the worm for a snack.

Thank you for sharing your wealth of information!