Possibly a flatworm? Help id please

[impur]

Did a WC on my little cube yesterday and saw this guy on the glass. I have not seen a flatworm like this before, any ideas on an ID?

TIA!

 

[cloak]

I think it might be a nudibranch, as opposed to a flatworm. Lets see what others think.

 

[impur]

Hmmm well it definitely does not have any cerata, I'm not sure if there are nudibranchs without cerata?

 

[Calappidae]

Looks pretty flat to me with no antenna either.

 

[pagojoe]

There are plenty of nudibranchs without cerata, but I can't see enough detail to be sure whether it's a flatworm or nudibranch. If it's a flatworm, it's one of the species that mimic nudibranchs (there are a bunch that do). It does look like it has horns or rhinophores, but I can't tell from the pics whether it has an external gill on the dorsum.



Don

 

[impur]

There are plenty of nudibranchs without cerata, but I can't see enough detail to be sure whether it's a flatworm or nudibranch. If it's a flatworm, it's one of the species that mimic nudibranchs (there are a bunch that do). It does look like it has horns or rhinophores, but I can't tell from the pics whether it has an external gill on the dorsum.



Don

Thanks for the info Don!