The term "red terror" is interchangeable with both xCichlasoma festae, or uropthalmus.
To determine in a photo with any certainty whether male or female, the dorsal fin would need to be extended. Females have a dark area there.
Here are some uropthalmus in nature, there are many females that are obvious by the spot.
https://www.youtube.com/watch?v=Zb3v0VJTg5c
