A. megaptera or A. piaroa?

[SpeckledJellyfish]

This male was sold to me as Piaroa, but I finally saw his dorsal fin today. It looks more like Megaptera to me, however his coloration doesn't match any of the Megaptera pictures I can find. For those familiar with either of these, which do you think this male is?

(Sorry the pictures aren't great - I swear he knows I'm trying and is just lurking in the worst spots! If you click on the photos they come into focus at least.)

 

[Frank Hättich]

Only the first photo is helpful and it strongly points towards megaptera.

 

[SpeckledJellyfish]

Only the first photo is helpful and it strongly points towards megaptera.

My thought as well. I'm well versed in the differences of the dorsal fin structure but wasn't sure if there are any other indicators on the body that might be helpful.