Koi Tail Section Bent upwards what is wrong???

[Giovanni]

Koi tail section is bent upwards at the spine, took it out my pond because I thought it was dead, but it is still alive for about 2 weeks now in an aquarium. it seems to be suffering though and showing no signs of recovery. Anyone know what this is, and what to do???? HELP!!!

 

[Giovanni]

Also Can't swim. No Signs of Parasites or disease. All other fish in pond ok, and Cloud minnows in Aquarium ok.

 

[WaterGardener]

Sorry to say this, but from what I understand, that "C" shape is indicative of a dying fish.

As for the bent tail, it could have been an injury of some kind or caused by an electrical charge to the water, like a lightening strike or a pump problem if the pump is in the pond. It's not uncommon that only one fish shows visible signs.

Could possibly be fish tuberculosis. Be sure to wear gloves when handling the fish since that can be transmitted to humans. Not with the symptoms we think of with human tuberculosis though. It's caused by a mycobacterium.

Also, could possibly be nitrite poisoning. Check your water parameters.