Koi, or nishikigoi, are ornamental carp from Japan. They are very popular as pets in aquariums and small ponds. They are often deemed to bring good fortune so taking good care of them is important. Koi fill their swim bladders by swallowing air and forcing that air into the swim bladder to rise to the surface. Pet stores and even aquatic veterinarians have people ask them about "swim bladder disease". Most often it isn't a diseased swim bladder at all, there is something in the fish's environment that is causing a problem with the swim bladder. Left untreated the fish could suffer. See if you can match changes in the fishes swim bladder to the behavior you might see. (3 points) Stays on the surface and can't swim well or hide. Sinks to the bottom and can't fill the swim bladder or feed The koi is stressed by dirty water with too much waste and too many nitrates, the swim bladder can't empty correctly. The koi eats food or insects that are too large, blocking the air intake. The koi has a parasitic infection, like a worm, that prevents air from entering the swim bladder.

1 answer

Based on the provided information, we can match the changes in the fish's swim bladder to its behavior:

  1. Stays on the surface and can't swim well or hide: This behavior could be due to the koi eating food or insects that are too large, blocking the air intake. If the koi is unable to fill its swim bladder properly, it might struggle to maintain its buoyancy and stay submerged.

  2. Sinks to the bottom and can't fill the swim bladder or feed: This behavior likely indicates that the koi is stressed by dirty water with too much waste and too many nitrates. The poor water quality negatively affects the koi's ability to function normally, including the proper functioning of the swim bladder.

  3. The koi has a parasitic infection, like a worm, that prevents air from entering the swim bladder: This could correlate with a general lethargy or abnormal swimming behavior, as the parasitic infection can inhibit the koi's ability to effectively manage its swim bladder and maintain buoyancy.

So, in summary:

  • Stays on the surface and can't swim well or hide: Koi eats food that is too large, blocking air intake.
  • Sinks to the bottom and can't fill the swim bladder or feed: Koi is stressed by dirty water with too much waste and nitrates.
  • Koi has a parasitic infection: Prevents air from entering the swim bladder, leading to abnormal swimming behavior.