Fish behavior

[Jonna]

I have the lights in the pond on a timer and I haven't reset it for DST so they are on till 1am.  I just went out there and snuck up on the fish, if they see me they wake up and come begging.  All the Wakin were asleep, lined up like a mothball fleet of submarines, tails to the current.  The 3 koi were zooming around like bad neighbors who play loud music all night, running in between the Wakin, brushing them with their tails, making them have to readjust so their tails were aligned to the current.  I thought it was really funny.  Do koi sleep?  Clearly the Wakin like their down time but are the lights keeping the koi awake?

[the Julles]

Fish need sleep in order to recharge their bodies and battereis, just like people do.  They can probably sleep with the lights on, but sleep is always better when it's dark - so the body can produce those sleep harmones, of which I forget the name right now.

I don't think koi sleep as much or as deeply as other fish.  I know that mine do some mighty mysterious things during the dark hours.  I have some floating baskets in the pond, to house plants and keep their roots safe from the koi.  Not infrequently, in the morning, I will find that a koi has jumped high and far enough to land himself inside one of these baskets.  This has never happened during the daylight.  So, whether they're playing or catching night-bugs or just getting exercise, there is a lot going on at night that doesn't happen during the day.