GoodTr8s

Mike

The symptoms you describe make it sound like dropsy or pop-eye. These conditions are usually brought about by poor water quality or bacteria from recently introduced fish.? Before you use any medications, try to improve the quality of the water with water changes over the next week and see if the condition improves. If it doesn't, then try medication. An anti-bacterial such as Maracyn-Two can be used to treat them. I would recommend using a quarantine tank for treatment because the medication may kill off the beneficial bacteria in your tank as well, causing it to re-cycle.

More info:
http://www.fishlore.com/QuarantineTankSetup.htm
http://www.fishlore.com/Disease.htm