I have had this Red Devil for 4 years now. I first got it with another one, and raised them together. Initially both fish were about the size of a US quarter. This fish grew MUCH faster than its tankmate, and ultimately killed it and any other tankmates it has had. Now this fish is about 8.5 inches long. While I know that males are larger than females, what I do not know is how large they can get relative to one another. Also, I understand that males get a nuchal bump, but I was unable to find at approximately what age this really blooms. This fish here has had the beginnings of one for a long time now. The fins also seem more pointed which from my understanding is indicative of a male, along with the more rapid growth. But, I am really not certain, thus this topic. Maybe someone with more experience can tell. And yes, "The Big One" is the fish's name......for an obvious reason =P.