I bought a 130 gallon yesterday and one fish may be sick

[Mark K]

One of the fish has an "S" shape to it. I tried searching, but the results were conflicting.

The tank was filthy and not well taken care of. I will change that. Here are a couple pics of the fish. What do you think.

 

[piranhaman00]

Im pretty sure that is a genetic mutation that can occur from inbreeding. Cant recall exactly but I remember finding information about it when I noticed it a lot in goldfish tanks.

 

[Rocksor]

That could also be the result of poor water parameters. I would just euthanize the fish.

 

[Mark K]

A mutation or bad water damage sounds much better than a disease. I thank you for your help.

 

[robham777]

Could be genetic or an old injury, but fish TB can also cause spinal deformities. You should remove the fish to be safe.

https://www.petcha.com/common-tropical-fish-diseases/

"If a fish has a bent or curved spine, it is most likely infected with a Gram-positive mycobacteria (Mycobacterium marinum or M. fortuitum). This is commonly referred to as fish tuberculosis, piscine tuberculosis, acid-fast disease or granuloma disease. ... Remove any fish that appear affected."

 

[Mark K]

The fish is dead.