Wow....something happened today that may have made my mind up that the fish in my first post is a male.
As I said, the fish in the second picture was just acquired yesterday and was new to the tank, and is slightly smaller than my original green terror in the first picture.
I left for most of the day today, and when I turned the tank light on tonight to find the second green terror was TORN TO SHREDS by the green terror in my first post. It was alive but not doing well...and I also noted it was pooping white & stringy (parasite). I put it out of its misery (this is hard to do by the way) as I did not want it to suffer any more or get my other fish sick.
Judging by this behavior...I'm really leaning toward male.