First and foremost:
What size is your tank? 2 gallon
What temperature is your tank? 85 degrees F
Does your tank have a filter? No
Does your tank have an air stone or other type of aeration? No
Is your tank heated? Yes
What tank mates does your betta fish live with? None
What type of food do you feed your betta fish? Betta pellets and dried bloodworms
How often do you feed your betta fish? Once a day
How often do you perform a water change? Once a week
What percentage of the water do you change when you perform a water change? Full
What type of additives do you add to the water when you perform a water change? Aquarium salt, Aqua Safe Plus
Have you tested your water? If so, what are the following parameters? No.
Symptoms and Treatment
How has your betta fish's appearance changed? Yes.
How has your betta fish's behavior changed? No.
When did you start noticing the symptoms? About two months ago.
Have you started treating your fish? If so, how? No.
Does your fish have any history of being ill? Ich and fin rot, both resolved.
How old is your fish (approximately)? About a year old.
Okay, so now that that's over with...
Chibi got a big lump on his left side about two months ago. It was perfectly round, and only on the left side. He showed zero change in behavior, no difficulty getting around, still super active, etc. Eating fine, swimming fine, still getting mad at anyone who wants to look in his tank (flaring), etc. I did some research and decided it was likely a tumor. Needless to say, I was very sad. But since he didn't seem to be suffering, I figured I'd just let him live out his life until things really started to change.
Then one day I went to feed him and it was gone completely. Now, I feed him daily. So this literally happened overnight. I was completely thrown off. But hey!! At least it wasn't a tumor.
It's been about three weeks since it disappeared, and this morning it looks like it's coming back again. It's not as big, but it's getting there, and I'm sure soon it will be the same size as it was.
I guess my question is...what is it?! And how can I get rid of it for good? He doesn't seem uncomfortable at all, but I obviously can't ask him how he's feeling.
I thought he was constipated at first, but since it was only on one side it seemed that that was not the answer. Now I'm thinking that's maybe what it is.
Any ideas would be awesome. Thank you!!