Jack Dempsey (sick???)

[mindi]

I have a Jack Dempsey fish that I've had for approx. 1 yr (along with a Red Oscar) in a 60 gal tank. My JD is approx 5 - 6 inches long now. My Oscar is 8-9 inches. My Oscar just laid eggs about a week or two ago, but they obviously did not hatch. Now, my Jack Dempsey is acting very strange. It is laying upside down on the rocks (mouth on the rocks, tail straight up in the air), or sideways on the rocks. I also haven't seen it eat for about two to three days. It frequently has his mouth open for long periods of time. There is a bulge (bubble-like, sticking out almost 1/3 to 1/2 inch) around the hole on the belly (don't know whether this is the anus or whatever the other part is called). Could it be getting ready to lay eggs also? Or could it possibly be sick? I don't know what the pH is, but I change the water (25% during vacuuming) every week or two. Have a Penguin 330 filter, and the water temp is typically 77-78* (submersible heater to keep temp constant). Thanks for any information you can give me.

 

[mindi]

Update - FYI
After all the research that I did. I think he had Malawi Bloat and Popeye, possibly something else. He died last night. My Oscar had just quit eating yesterday, and had also gotten popeye, with a white something or other on his eyes. I treated the tank with anti-biotics and a pH balance tablet. My Oscar is back to eating this morning, and his eyes have cleared up slightly (still see some white stuff, but not as much). I cleaned the tank, vacuumed etc, and changed the filters prior to adding the antibiotics and pH stuff, tank temp is 77*F. Any other suggestions on what I should be doing/watch for, etc. I know I have to add the anti-biotics on days 1, 3, & 5. Thanks.