How Long Will A Fish Survive In The Dark

[STD]

My filter on my FW tank is a sump 3/4 filled with ceramic rings

Just had a look in it an saw a tiny plecostomus that I thought had died a couple of months ago

I'm not sure what to do about it as catching it would be a pig

I suspect it's been in there for a while

How long do you think it will survive in there as it isnt lit ?

 

[chr15_8]

fish dont need light to survive. ive seen somewhere they prefer the dark.
but if its needs algea for its diet etc im no help

chris

 

[n3ont3tra]

Actually, fish do need light to survive. There's a link on it somewhere... I can't seem to find it, though. >.< It doesn't need to be top-of-the line metal halides or anything, just a little sunlight will do. But they do need SOME light.

 

[afishdude]

fish need light for the same reasons we do, our skins need it to produce vitamin D.

 

[chr15_8]

opps looks like im wrong

when you say sunlight can it be indirect sunglight? will have a look for the article im thinking of tommorow when i get back form work

chris

 

[pica_nuttalli]

mostly, fish need a day-night cycle for optimal health. thus leaving the lights on all the time is not good for them either.

indirect lighting is good enough for the most part, but it's better to have *some* direct lighting.

 

[melz]

fish need a light to be on for 10hours a day , to little light makes them ill and to much light could also make them ill,

 

[darkwolf29a]

I would catch it, and make sure that it can't find it's way back there again.

Fish do need light to maintain their cycles, just like you do.

It may be a PITA, but you should catch the little guy.

 

[Jules H-T]

It may be a PITA, but you should catch the little guy.

Too right, you can't leave it in there! Get the rings out one by one if necessary and rescue the little fish!

 

[STD]

I would catch it, and make sure that it can't find it's way back there again.

Fish do need light to maintain their cycles, just like you do.

It may be a PITA, but you should catch the little guy.

yup your right

If I take out all the media but keep it under water will it be OK?

Don't want to kill off my filtration

 

[ibbledibble]

drain some tank water into a bucket or something, transfer the media straight into that and just try and get it all done as quickly as possible. hopefully should be fine.

 

[STD]

drain some tank water into a bucket or something, transfer the media straight into that and just try and get it all done as quickly as possible. hopefully should be fine.

Not so easy I'm afraid

The sump is about 70litres and a very tight fit in the cabinet so emtying it is a pain

 

[Darkstar]

I've never read any article suggesting fish wil get ill with too little light or that they require if for vitamin D production....so some scientific evidence here would be appreciated.

Other than providing a daily cycle for them there is very little need for light. The main reason for light is so you can see them.
Considering some of the blackwater rivers where a lot of fish comes from have little or no light at all reaching the bottom I find the above statements very doubtful indeed.

 

[CFC]

Can someone explain how a nocturnal catfish or knife fish (or any other nocturnal reclusive fish for that matter) that spends the daylight hours hidden in a cave manages to survive if it is so important for fish to have light?

I have fish that spend their entire lives buried in sand with only their eyes showing and others that i have seen so rarely that i forget i have them in the tanks, they are also kept in unlit tanks on the bottom rows of my racks but they have been alive for years, surely they should be dead. Explain to me how it is that most people with large fish houses have their tanks lit by room lighting only but dont have tanks of dead fish?

Also if the fish require UV light to synthesis vitamin D then that means that any tank with a glass cover is useless as glass absorbs UV light, ever wondered why you dont get a sun tan through your windscreen or from sitting at a desk near the window?

I'm sure that there are SOME fish species in the world which have lighting requirements, but as far as i am aware and have experienced none of the popular fish in the hobby do. This is probably commercial propaganda started by one of the lighting manufacturers to scare people into buying expensive aquarium lighting.

 

[Catfish Jack]

just think about some of those cave species of fish, they go their whole life without any light.