Please help identify

[Kirstin]

Hello, I noticed this critter yesterday. It is very filmy, seem to have spots, and cup shaped. When I moved my light to get a better picture it retracted into the sand. It’s about 1/4“ tall and 1/2“ across.

 

[sfin52]

Looks like a sponge

 

[Kirstin]

It does not have any tentacle. I can’t get a clearer picture. It is a single cup, pale yellow

 

[Kirstin]

Looks like a sponge

Do sponges retract like feather dusters or Aiptasia?

 

[sfin52]

No

 

[Kirstin]

No

This completly disappeared when I moved the light. It is translucent yellow. It moves in the current. It’s really hard to get a good picture. It is just behind the piece of rock

 

[Bbfishb81]

Might be a type of feather worm. Hard to tell in pics

 

[samnaz]

Feather duster