My catfish is suddenly BALLOONING and listless, please help!

[fishkeeper07]

My 7" catfish (synodontis nigriventris, I think) has suddenly become huge and is very low energy. There is a "chunk" of off white fleshy growth that narrows into a strip which runs down his(her?) underbelly. He has stopped feeding, which is very unusual for him as he is the most active feeder in my tank. His belly and center mass seems to have ballooned about 50% in the last 48 hours. The rest of the fish in the tank seem fine. I have had this fish for over 4 years. In the last 6 months he has gone from being a recluse to being very active and dominating the tank, but isn't aggressive, just large and quick.

He is also doing this weird thing where his is positioning himself at the front of the tank vertically on top of the gravel, as if he is "standing" on his tail fin.

I have had no new additions to my 50 gallon freshwater tank in over a year. I do 20% weekly water changes. As the tank has been very stable I have stopped testing the water parameters, I'll check them tomorrow when I get my kit out of storage. The tank is not overstocked.

I just dosed the tank with Melafix tonight after noticing the underbelly growth.

Please help, this guy is my favorite fish and the star of my tank, I'd really hate to lose him.

Thank you!

 

[V227]

My guess is that your Syno is very constipated, resulting in swim bladder problems. There are several remedies listed online.

 

[fishkeeper07]

Thank you for your advice, unfortunately my favourite fish didn’t make the night. I’m amazed how quickly this all happened. I wish I could have done something sooner, my tank isn’t the same without him. I’ll have to make sure I include more fibre in my feeding.

 

[V227]

Considering your catfish passed so quickly, the actual problem was most likely "Bloat". There is no known single cause agent for the condition, but the end result is a swollen gut full of lethal bacteria. There really was nothing you could have done to save the fish.
Ive read that in a severely constipated fish, the compacted waste creates a very good environment for lethal bacteria to grow.
The only good thing about losing a prized fish is that you get to go back to the fish store and buy another.

 

[fishkeeper07]

Thanks so much for reassuring me nothing could be done towards the end. I know what to look for now going forward.

My prized syno will be missed but I am excited about the silver lining of finding a new one.