IIRC, RES should have a tiny red spot on the ear tab on at least some of them. HBG, check for larger than normal mouths and yellowish tinted margins on the anal/caudal/dorsal fins. Standard BG will not have any blueish mottling/streaks on their cheeks either.
I've seen so many fish that I usually don't have to look for specific things to determine the species. I just know what it is. You made me think a bit there!
Sort of like you reading this. You don't have to think about each word, sound it out and figure out what each word means to be able to read the forum, right?
