Here's what I've got...
I started with 5 cons and 5 firemouths a couple of months ago in a 55. I've been hoping to get a breeding pair of both and take back the others. All of the fish were very young when I got them, all about an inch or so.
I took two male cons back last week which left one male and two females.
Kept all five firemouths because no pairs have formed. All fish are growing like crazy except for one female con.
Bought more rock and rearranged the tank two nights ago. The next day a pair of cons hooked up. They are now very, very dark and very, very aggressive. At the same time this was happening, my firemouths gained incredible colors. They were nice before, but I can't believe the red on their stomachs. The firemouths are now getting chased by the cons, and fighting with each other. They square off with flared gills and turn almost black.
It is interesting that not much was happening in regards to pairs forming until I added more rocks/caves and rearranged the entire tank. My cons paired up almost instantly after the new setup was in place.
One thing about my con pair, they play with each other constantly
. They swim thru caves and small cracks in the rocks. I have a feeling they are looking for a place to spawn. You can really tell when they pair up, they curl up against each other. Also, my male used to chase the female and she would take off to the other side of the tank. Once paired, she darts and stops, then chases him, they go back and forth. My ten year old son can't get over how much fun these fish are...neither can I!
I hope to quickly pair/sex two of the firemouths and take the others back. I may have two pairs forming, but have to wait and see.
If you are thinking about cons, go for it. I have another tank that I will try to use the fry as feeders. I also made an informal agreement with my local fish store to take some in for credit. They are very cooperative, especially since their main caretaker is a former student of mine
One of my neighbors is also going to take some fry for feeders.
I will get some updated pics posted soon, here are a few older ones. Good luck, I look forward to hearing what you decide.