Any idea what this is?

Ivan75 · Dec 17, 2016

I thought this was just a snail that had gotten down below the sand line. However, the "top" side of this thing is flexible. As you can see it moved away from the glass, it twisted it's body.

SandJ · Dec 17, 2016

Polyclad flatworm? Found a picture of this one and it said it eats mollusk.

Dtfnemo · Dec 17, 2016

Looks like a clam, I am not sure

Ann_A · Dec 17, 2016

M guess would be either a flatworm of some kind (not sure whether a polyclad or some other type), or a sea slug, not necessarily a nudibranch specifically.

Having had a leopard flatworm hitchhike into my tank (picture posted by SandJ is of a leopard flatworm), I can tell you it's definitely not that specific species but it could be a related polyclad.

Regardless of what it is though, I hope you can pull it out if you have not already done so, at least until it can be positively identified.

stevo01 · Dec 17, 2016

In the other thread you made about this, lionfish lair suggested it may be a chiton.

Ann_A · Dec 18, 2016

stevo01 said:
In the other thread you made about this, lionfish lair suggested it may be a chiton.

That is a very good suggestion actually. The underside shown in the first photo does resemble the underside of a chiton more than anything I've thought of so far. The clearly defined foot in the photo is not present in most sea slugs or flatworms that I am aware of.

Ivan75 · Dec 18, 2016

I am new to the forum & figured I would be able to go in and delete the first post from the general group, & leave this in the hitchhiker thread. Sorry for the double post.

SandJ · Dec 18, 2016

stevo01 said:
In the other thread you made about this, lionfish lair suggested it may be a chiton.

I thought it looked like a chiton (or even a limpet from the bottom), but in the second picture it looks like the part that would be the chitons top (hard part) is bending like it is soft and fleshy.

Tahoe61 · Dec 18, 2016

The valves (look like plates) are not a rigid structure, they allow for bending .

Maritimer · Dec 18, 2016

I'll add one more voice to the chiton chorus ... total good-guys!

Yours looks pretty cool, with that red up top . . .

~Bruce, who has only one chiton that he knows of, and has only seen it one time!

stevo01 · Dec 18, 2016

Ivan75 said:
I am new to the forum & figured I would be able to go in and delete the first post from the general group, & leave this in the hitchhiker thread. Sorry for the double post.

I think your first post asking for an ID was a great first post! It was ok to post it where you did, but as you have found there is a specific board for ID'ing critters too

Welcome to R2R and looking forward to seeing your tank thread.