They don't... koi use a two chamber swim bladder that keeps them upright and vertically balanced. At times they will gulp air to refill a bladder. They can live with a damaged bladder fairly fine but they tend to sink more but not flop over. read more
I have had koi that have developed issues, some cured if it was an infection or blockage and other never recovered. I have taken fish apart (necropsy) to asses the condition of that bladder. read more
Ron Sterbenz, Avid Japanese Show Koi Collector, Founder of the Upper Midwest Koi Club Answered Apr 20, 2016 ยท Author has 340 answers and 570.2k answer views Wow - these answers, don't poke it with a needle. read more
One of my Koi is laying on his side - his gills are moving as does his mouth. This happened 24 hours ago - we pulled him - Answered by a verified Pet Specialist We use cookies to give you the best possible experience on our website. read more