what's wrong with koi-u-chi???

Question

ok, my butterfly koi's front fin(don't remember what you'd call it so, lets just say its one you'd concidered to be a fish' arm.

anyway that fin is stiff like a board and he seems to keep it close to his side.thats vthe only thing that seems to be wrong.

so does it sound like some kind of disase?which one(s)

or do you think he just injured it?
do you know of anything that could help it get better?

its been like this for over a week

Answer 1

Sounds like an injury, this happens quite often in koi. Especially if you have more than one and it is breeding season.

Clamped fins are usually more than one and it is as was mentioned an environmental issue.

Honestly, how large is your koi and is it in a tank or in a pond? If he is in a tank it could be his tank is too small for him to swim properly and he damaged his fin.

I would watch him for a while, if he is eating and not showing any other signs of outward disease let him be. Remember koi need a high protein and fiber diet with low fats. Lots of veggies. Also, be sure the water isn't too warm. Watch him for a while longer. Feel free to email me with questions.

Answer 2

It sounds as though your describing what we would call clamped fins, although this would be unusual to only have the one. Other than a posssible injury (if he's regularly using the other fins), it usually indicates that there's something wrong in his environment.

If this is a fish that's been kept in an aquarium, my first thought would be the water quality. Do you have a way of measuring the ammonia, nitrite, nitrate, and pH? You might want to do this if he's in a small pond as well. If you don't have a way of testing this, and you haven't done a water change recently, I'f first suggest changing about 25-35% of his water, and doing this again tomorrow. If there's a chemical buildup, this should take care of it to the point you'll notice some improvement.

If his behavior doesn't change, and the fin doesn't show obvious signs of injury, he may have parasites. This can be treated with non-iodized salt, starting at about 1 teaspoon per gallon of water and increasing it to two tablespoons per gallon over a few days.