Ah, sorry, I should have clarified, but I was rushing too much - I meant specifics on where the different kinds of teeth are in the mouth (though I don't know if they'd be able to easily do so with a live specimen), as the placement of the teeth can be used to differentiate some species (though thinking about it this morning, I doubt that'd be necessary at all given the unique patterning).
Anyway, I'll keep looking and see if I can find a match here.
E. anatina (the currently recognized species) is found in both the Mediterranean and the Eastern Atlantic; depending on which source you consult, it may list one or the other or both.
Yeah, my thoughts were potentially a hybrid of E. anatina (/E. sanctaehelenae) and something else, but it is unlikely (and again, I feel pretty confident that I've stumbled onto a picture of this species before at some point and just can't remember where).