Sleeping fish

[Endgame319]

Have you ever caught your fish sleeping when you turn the lights on in the morning? I notice that my tiger barbs sleep vertically, with their nose pointed toward the ground. It was kinda weird the first time I saw it. The serpaes just sorta sit in the corner and lose their color. And my cae's stripes fade and all these spots appear, its sorta weird... What about you guys?

 

[Menagerie]

The few times I caught them napping--their coloring was off. I must admit--the tank lights are on until I go to bed and the sun rises way before I get up.... The fish are always up while I am!

 

[TankGirl]

Here are some more thoughts on this topic:
http://aquariumadvice.com/viewtopic.php?t=18994&highlight=sleeping+fish

 

[tkos]

My cories tend to sleep on plant leaves facing upside down. Very odd but cute. My flying fox is always white first thing in the morning and when the light comes on so does his colour.

 

[jasno999]

YEah my tetras always lose their color at night it is very interesting. I never see the guppies asleep but I know they do sit on the gavle and relax at night. But my crab and shrimp are most likley active at night so they probably bump into a fish every now and then to wake them up.


Why do fish lose color when it is dark out?

 

[purplestarfish]

i've seen it too. My tiger barbs fade away their stripes, but the kuhlis and the clown loach keep theirs (proly due to their nocturnal nature). I actually know why they lose their colors! - at night, if a neon tetra shone its neon lights, it would be easy pickings for any lurking predators to find and finish off. Therefore, it fades them away. As for fish like tiger barbs, they fade away their stripes, which would otherwise (in the day) enable them to blend in between the reeds they live in (kind of like tiger stripes that blend into their landscape). I think when it's night, everything is uniformly dark, so the broken patterns of light and dark would also be distracting, whereas if they are all light, they merely look like dapples in the water. (You may be able to tell that I don't know as much about the stripes as I do about the flourescence . . . but that's my best guess. cheesy grin: )

 

[Christmasfish]

Expanding on Puples post:
It probably uses some portion of their metabolising energy to keep proper color... that would be why they fade when ill too. that is why ultra colorful fish are literally the picture of health. They can afford to be at full display because the energy cost is less when they are fat and happy.
It wouldn't make survival sense to use energy keeping up a color that can't be seen at night or while resting except as a brighter spot in the murk for a predator to target. that would be like sleeping in make-up ^_^. And we all see what that does for the morning!
Especially it would be waste for the fish at dark in the color spectrums that are unseen at night anyway.

 

[Todd2]

My danios always sleep near the surface and my cories are usually sleeping were I can't see them.