Please help ID - no idea!

[RubyRed]

We moved our live rock around and found this hiding in the back. It moves slowly and seems to change shapes, peanut and apple shapes.

Any ideas?

 

[RubyRed]

My wife describes it as " like a gel apple with red moving parts inside and a long tail like thing."

 

[RubyRed]

The part on left opens up and sand comes out. Better photo...

 

[ktomminello]

Looks like a sea cucumber or sea slug to me...

 

[RubyRed]

I've been looking through photos of sea slugs, sea cucumbers, sea squirts/tunicates, sponges, and anything else I can think of... Nothing really seems to match. But there are tons of varieties of each - who knows of I will find a match.

Anyone else have a guess? It seems like a filter feeder, so I'm assuming that its beneficial. The tank is 29g and is 3-4 months old.

 

[Leonardo7689]

peanut worm??? Try to google it and let us know what you think

 

[Leedowlrods]

I'd go with a peanut worm too

 

[AbsoluteFaye]

When I had my sea hare, a spot on too opened up and sans came out. Could possibly be a type of sea hare.... So weird looking though.

 

[RubyRed]

Thanks for the suggestions! After a lot of googling, I found a peanut worm photo that has similar coloring and texture to what we have in our tank. Also, it stretches out several inches and doesn't have the sea hare "rabbit ears".

So, I'm going with it being a Peanut Worm for now unless we observe something to the contrary.

Thanks to everyone who helped! This really had us stumped!