Does anyone have any ideas on this? I'm completely baffled. I disagree with ZTL listing it as a Marbled Torpedo; it looks relatively numbfish-like to me (although I've never seen a numbfish).
Are we looking at the wrong order? Position of the dorsal fins and the shape of the tail is unusual for Torpediniformes, but not for Rajiformes. I know there are major age-related differences in Torpediniformes that for the most part haven't been properly documented; do juveniles ever have dorsal fins and tail like this? It's perhaps also worth keeping in mind that new species of Torpediniformes are described every few years and it is likely that quite a few undescribed species remain.
I saw these rays again today. They do seem to have matured a bit. I'll post photos when I'm home.
Apparently there may have been at least four in the tank when we visited in October VC! Today I saw 2 clearly, with what could have been the edge of the disc of a third.