Sabi

Found these under rock here in the local waters. What is it, does anyone have an idea?

Emory

Hi Sabi! Welcome back to fishlore! We have not met, so "hi!"

That looks like a clump of earthworms. I don't believe they would be living in the water though. They can for a short time. Had the water level recently risen?

Lucy

I really can't be sure, but they look like earth worms.

Sabi

In the sea??

Emory

huh.... no clue then. Sorry.

Lucy

Oh, sorry, you had said waters...I was thinking lake or pond.
I hope someone can identify it for you.

cerianthus

Could be sort of bristle worm which can be commonly found on/in the uncured live rock on the market. This can be delicacy for certain fish as we use worms (sand worm, blood worm) to catch fish in the ocean. Yummy! LOL
If using for reef, definitely put the rock in F/W to remove all the worms, not knowing exactly what it is.

Rbacchiega

hard to tell, but I would lean more towards flatworms...bristle worms are more often than not noticably bristley...(is that even a word!?)

Sabi

Hehe i didnt take the rock. No way was i going to put those slimy creaturtes in!
Well they did have spikey things.