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Fish don’t sleep???

Magnum Man

Magnum Man

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I woke this morning, early, before my aquarium lights started coming on…. Pretty much pitch dark… In the faintest glow of a night light across the room, I could see the silver body’s of the Tin Foil Barbs circling in the tank… I’m sure they are at rest, but even sea sharks shut down, but these guys don’t seem to fully shut down… they are “normal” and have grown to adulthood, in the aquarium… I can’t remember sitting in the dark here for a long time, but the tanks being in the basement, it is really dark down here, just the one very dim night light across the room…

Maybe their internal clock tells them the lights will start coming on soon???

While I was typing this, the 1st back ground ( dimmest ) light came on, in another tank… everyone else is sleeping, but not the tin foils, they were just circling in the center of their tank…
 
4 heavily stocked tanks down here… I suspect some of the catfish are more nocturnal, naturally, and adjust to aquarium life, where they get fed, when its light… Cory’s and Plecos, for example, are moving, as fast as I can see them, after the lights start coming on… I couldn’t really "see" the tin foils, but the glinting of the night light, off their silver bodies, as they circled in the tank… some fish sleep in for an hour or more after the tank lights come on… African tetras are moving at 1st light, most South American tetras slowly start coming out, well after the lights are fully on…
 
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I've seen some interesting things while night diving on reefs and freshwater lakes. Some species are in a dormant-like state where you can fin past them and they don't acknowledge the presence of a monster wearing a BCD and air tank! Others move away indicating they are not completely asleep. Interestingly, I have noticed that within some species, the adults will go into a 'REM' sort of state but the juveniles of that species were moving. What is most fascinating is shallow diving with a full moon. All sorts of activity. Great topic @Magnum Man.
 
The standard way of catching very smart Cichlids is lights off in a dark room, with a net and a flashlight. It can save you from uprooting plants.

I love pencil fish, because at night, they have totally different colour patterns. It's really cool, like having 2 types of fish in one body.
 
A bunch of times I've found nurse sharks resting on the bottom. No forward movement at all. They are really cool. I have read (never seen) about a couple of other sharks that can rest without forward movement too. They suck water into their mouths and out the gills.
 
I think most sharks do rest, it was just my understanding, that they "park" in areas of higher water flow... that, & I'm sure fish breath while they sleep, just like we do... although perhaps less evolved species maybe need the flow, to assist in breathing...
 
Sounds like quite a scene with your Tin Foil Barbs this morning. It's cool how they keep moving even in the dark. Maybe their internal clock does know when the lights are about to come on. Fish are fascinating like that! Love how you've set up your basement tank haven.
Magnum Man said:
I woke this morning, early, before my aquarium lights started coming on…. Pretty much pitch dark… In the faintest glow of a night light across the room, I could see the silver body’s of the Tin Foil Barbs circling in the tank… I’m sure they are at rest, but even sea sharks shut down, but these guys don’t seem to fully shut down… they are “normal” and have grown to adulthood, in the aquarium… I can’t remember sitting in the dark here for a long time, but the tanks being in the basement, it is really dark down here, just the one very dim night light across the room…

Maybe their internal clock tells them the lights will start coming on soon???

While I was typing this, the 1st back ground ( dimmest ) light came on, in another tank… everyone else is sleeping, but not the tin foils, they were just circling in the center of their tank…
Click to expand...
 
Archerfish said:
I've seen some interesting things while night diving on reefs and freshwater lakes. Some species are in a dormant-like state where you can fin past them and they don't acknowledge the presence of a monster wearing a BCD and air tank! Others move away indicating they are not completely asleep. Interestingly, I have noticed that within some species, the adults will go into a 'REM' sort of state but the juveniles of that species were moving. What is most fascinating is shallow diving with a full moon. All sorts of activity. Great topic @Magnum Man.
Click to expand...
The way nature works, every animal has to have some defense mechanism in order for the species not to go to extinction. Sleeping or resting requires adaptive behaviors based on survival.

I like how fish get used to a certain food, and then when you try to switch it up, they won't eat it. That shows some conscious thought processes too.
 
GaryE said:
I love pencil fish, because at night, they have totally different colour patterns. It's really cool, like having 2 types of fish in one body.
Click to expand...
I’m planning on getting some pencil fish but I had never heard of this! What does it look like?
 
JackGulley said:
I’m planning on getting some pencil fish but I had never heard of this! What does it look like?
Click to expand...
Here is a good writeup on the pencil fish types and their care.
www.fishlaboratory.com

Pencil Fish: Ultimate Care Guide - Fish Laboratory

If you’re looking for species of fish that are unique and small but somewhat difficult to care for: consider the Pencil Fish. A Pencil Fish is actually the
www.fishlaboratory.com www.fishlaboratory.com
 
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My new Betta, Patches, definitely sleeps. When lights are turned off, she heads into her “Tiki Head” bedroom. She stays in there all night.
And when I turn on the room lights and tank lights in the morning, she comes out quickly looking for me to serve her breakfast.
IMG_3553.jpeg
 
JackGulley said:
I’m planning on getting some pencil fish but I had never heard of this! What does it look like?
Click to expand...
I'm guilty of generalizing. Not all species get the colour differences at night. The best I had was marginatum, which seems to be showing up again after vanishing. It once was a bread and butter pencilfish. trifasciatus too.
 
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