Who’s this?

[Hunna’s Stunnas]

The last few weeks, I’ve noticed this thing stretching off the rock covered in my King Kong Yumas, into the sandbed. I only see it in the mornings, before the lights come on. The first few weeks it would retract the second I would shine light onto it. Now, it just chills and keeps doing what it’s doing. I’ve only ever seen the single arm/body, and only from this particular rock. Even after moving sides of the tank the rock is on. Any idea what it could be?

 

[1112-425XL]

Looks like a micro brittle star tentacle. Is the photo magnified?

 

[EeyoreIsMySpiritAnimal]

The last few weeks, I’ve noticed this thing stretching off the rock covered in my King Kong Yumas, into the sandbed. I only see it in the mornings, before the lights come on. The first few weeks it would retract the second I would shine light onto it. Now, it just chills and keeps doing what it’s doing. I’ve only ever seen the single arm/body, and only from this particular rock. Even after moving sides of the tank the rock is on. Any idea what it could be?

Is it rigid or wiggly?

 

[EeyoreIsMySpiritAnimal]

Possibly a baby peanut worm?
@ISpeakForTheSeas

 

[Hunna’s Stunnas]

Is it rigid or wiggly?

Wiggly. If it was larger, I’d imagine it was something like a tiger’s tail cucumber or something. But it’s tiny. Only a few inches long fully stretched out, and the thickness of lead in a #2 pencil roughly.

 

[Solo McReefer]

Spoon worm

Sticky hand

 

[EeyoreIsMySpiritAnimal]

Wiggly. If it was larger, I’d imagine it was something like a tiger’s tail cucumber or something. But it’s tiny. Only a few inches long fully stretched out, and the thickness of lead in a #2 pencil roughly.

Interesting. If you've only seen one and it has been living in the same place for more than a day, it's probably not a brittle star arm.

I would lean toward it being harmless though... does it grab at food?

 

[Hunna’s Stunnas]

Interesting. If you've only seen one and it has been living in the same place for more than a day, it's probably not a brittle star arm.

I would lean toward it being harmless though... does it grab at food?

Your suggestion of a baby peanut worm may be it. Quick google search results in similar images.

 

[ISpeakForTheSeas]

Possibly a baby peanut worm?
@ISpeakForTheSeas

Yeah, that's a peanut worm (Sipuncula); spoon worms (Echiura) are fairly similar, but their stretchy parts (the proboscis) are flattened rather than tubular or branch into two parts the ends.