Is it true that koi sleep and how do their sleeping patterns work? - #21837

I am really curious about how koi fish behave when it comes to sleeping. So, I’ve got this small pond in my backyard and I've been keeping koi for about a year now. At first, I thought they were just always swimming around, but I've noticed they seem to have these moments where they kinda just hover still at the bottom of the pond. It's gotten me wondering, do koi sleep? I mean, they can’t exactly close their eyes, right? Sometimes I watch them in the late afternoon and they look like they’re totally chillin’ out, just hanging. It’s fascinating! The other day, I was sitting by the pond, and I noticed one of my koi was just chilling there, not really moving much at all. I thought, do koi sleep right then? Or are they just taking a break? I also read somewhere that koi can actually rest and sometimes stay hidden among plants or rocks during certain times. But it raises a couple of questions for me. If they do sleep, does it happen more at night or during the day? And how long do they actually sleep for? Like, can they be disturbed, or do they wake up really easy? I worry sometimes because, to be honest, I’m not sure I’m providing the best environment. I’m always afraid something’s wrong if they’re just floating there and not swimming around. It makes me wonder, are they sleeping well enough, or is this just what they do? And, do koi sleep the same way that other fish or animals do? Is it even sleep? Also, I noticed that their colors look a bit more vibrant after what I think is their resting time, so does that mean they’re actually sleeping or just being lazy? Any insights about koi sleeping habits would be super helpful. How can I tell if they're getting enough rest? Is there a way to make them more comfy for sleeping? Thanks a lot!