not to dissagree with john himself. but the jaw on a aro can be affected throughout the lifespan of the aro. when younger, if he's a lil jumper when he freaks out, his jaw appearence can be physically changed. smashing feeders n hitting the glass multiple times in a life time. so many possibilities.
maybe its good enough of a concept to give you an idea, but i don't see this being a guarantee in any kind of way. i have 3 aros, and all 3 are different in every kind of way.
my biggest aro has a bigger lower jaw, but short lil lower trailerfins n very broad body. meilings aro has a nice big lower jaw, but really long trailer fins. very broad body as well. then my last one has a small lower jaw, but very long lower trailer fins and kinda slender compared to the other two.
i still don't see a way to sex an aro by its appearance.
but bderick. yours aros look amazing, they've grown so well and look so healthy. big thumbs up bro! u got the 350gal up n running already? i'd be moving them badboys like soon lol, bigboys don't play when they try to jump out dude but ur far from new, u don't need me saying that lol