My betta has become listless
This is one of my most active fish.
I have had him since May/June and he is usually always swimming and exploring his tank(5 gallon). He eats well and has always seemed healthy.
Friday morning I noticed that he was in a corner of his tank at the bottom and has been there ever since. He is kept in my bedroom where the a/c is turned on at night when the weather dictates. I thought he may have become too chilly,though the thermomitor always read 76,so I turned his heater on to warm the water. He did seem to respond to that change. He swam a bit and finally stayed at the top of the tank for awhile before finally retreating to his cave which is where he has been all night as well as today.
What's wrong here? Is my poor fish dying or is he just 'resting'?
Thanks for any advice.