What is this?

[Crocpete]

Found this on top of the sandbed after a major tank cleaning. I know I have a few bristleworms so maybe this is a piece of one that came off? It’s sctually moving! Freaked out the kids. Also that other circular thing, very thin like maybe a piece of a shell? Any help appreciated!

 

[Fin]

May be a nudi. Hard to tell with my eyesight and those pice. #Reefsquad

 

[Crocpete]

Slightly better pic

 

[Lovemyreef2015]

Looks like a piece of a bristle worm

 

[KJ]

Bristleworm.

 

[Lovemyreef2015]

The circle is the trapdoor of a snail

 

[saltyhog]

Could the round flat object be the operculum of a small snail? Hard to say on the mobile guy? #reefsquad

 

[KJ]

The circle is the trapdoor of a snail

+1

 

[Crocpete]

Wow, great thanks for the quick responses & info! Do all snails have trapdoors or just some? I only have ceriths, nerites, and nassarius.

 

[Crabs McJones]

Looks like a chunk of a bristleworm