How can you tell a koi is pregnant?

You can tell a koi is pregnant, or "gravid," by observing its physical appearance. A pregnant koi will have a noticeably swollen abdomen, often appearing round or bulging, especially as it nears spawning time. Additionally, during the breeding season, you may notice the koi behaving more actively or swimming near the surface, and males may chase them, indicating they are ready to spawn.