I had posted a question about a week ago but for the last few days I have had some bad developments I could use some help with. Basically I have only two fish in my 220, a 10 in. male dempsey and a 6 in. female dovii. Recently the both of them have been displaying what I assume is breeding behavior, the male shaking, lip locking and ultimately the female laying eggs. Nothing has come of their attempts, but it has had me cleaning the tank more often when the eggs go bad. Anyway after the last cleaning I noticed that the tank was a bit colder than I had wanted it, I'm thinking one of my heaters took a crap, so I added another heater and have the tank going at about 78 degrees. Since that day I noticed that the dempsey has become ferocious with the dovii. He wont let her move without hammering her, so basically she has spent the last few days hiding as best as she can. Im not exactly sure what the issue is here but my obvious guess would be the temperature change has the dempsey acting up. Ive heard the heat increase will increase metabolism and aggression but he seems uncharacteristically fired up. I lowered the heater and dropped the tank down to the low 70's last night, assuming it would help, but when I got home from work today it was the same story, dovii hiding while the dempsey stayed on patrol. My only other guess is that she's holding out on him, which I would assume would provoke aggression, but I cant make her give it up to test my theory. If anyone can help I shed some light on the possible reasons why my dempsey has got the bloodlust I would very much appreciate it. I would hate to lose my dovii if there is something I can do to help.
if you added other cichlids they would have to be large already, and to add to that a jack dempsey and dovii are about as mean as they come - that being said there isn't a whole lot you could do other than a tank divider.