My koi is continuously opening and closing its mouth... It is breathing rapidly and also its not able to eat.As it tries to eat due to continuously opening and closing the mouth it spits out the food.This abnormal behavior was seen since 5 days back.Before that it used to eat food and also breath normally. I have other fish in my tank and none of them breaths in such a way.I have also checked water parameters and have also done partial water change but it didn't help me.I also tried to see if it had pebble or pea sized rock stuck in its throat but I found nothing.
I am worried for my fish and appreciate any help.