Curious....

[Wendie]

Each day I turn the lights on in the tanks anywhere from 6am to 8am. You will see a fish every now and then dart about in the lower tank which contains small clowns, darios, a pleco and polka dot loaches. They start coming out later in the afternoon but I haven't checked the times.

Another tank contains some baby bristlenoses, three yo yo's and a couple clowns. The baby bristlenoses are out constantly. However, you will not see a single loach until 2:30pm - est - when the first yo yo makes an appearance. By 3pm they are all out chasing each other around and checking things out. By 9pm the clowns retire for the night. All activity slowly tapers off. You can actually set your clocks by them. The same thing applies to the smaller fish in the lower tank.

In a third tank in another room, I have to feed them before 9pm because the clowns have all disappeared for the night by then.

[angelfish83]

Fish have excellent internal clocks. Down to within five minutes. its scary.

If I set the lights 10 minutes later than usual, about 10 minutes before the lights turn off my bleeding hearts all swarm together and move to the back left corner and go to sleep, whether the light is off or not- they just know its bed time.

My Bolivian Rams will do this too.

I can't set anything by my (Polkadot??) loaches though- but its hilarious to watch them sleep sideways on top of eachother...

[Wendie]

My polka dots seem to sleep in the pleco cave. Every now and then the sand comes flying out the entrance followed by the loaches when he gets annoyed enough.

I have one Yo Yo and one clown loach that sleep together under a bridge. The others have their own cave complex or inside a log. I have a corner cave that one Yo Yo uses. He sleeps on the upper shelf and a couple black kuhlis sleep on another ledge.

It's embarrassing with the absence of fish in the tank during most of the day. If someone asks I usually say come back at 3pm. I still don't understand why they don't come out in the morning.