internal bio-clock?

[dzhuo]

Hi,
I want to know if fish,coral and other invert. have internal bio-clock or not? For example, if they are used (either in the ocean or in another tank) to light for a certain hours during the day (say 9am to 9pm everyday), will I be giving them a lot of stree if I decided to ligh my tank from say 12pm - 12am? Will the fish, coral, invert. etc adjust to the new lighting hours?

thanks!
david

[matrixnyc]

I think the Bio-Clock or Biological Clock only relates to Mating and feeding cycles, Notice I said "I Think" :)

I am sure you can adjust the times of lighting slightly each day to get the LiveStock used to the new times.

It is probably similar to how humans get Jet Lag. But if you do it a little each day, you should see no adverse effect.

Just my opinion, based on what I picked up over the years of watching Nature and Science Shows :)

[dzhuo]

Thanks for the info. That's what I think too but definitely want to confirm with the more experienced reefers here.

thanks!
david

[phistio]

perhaps it's not needed...but i personally light longer hours in the winter...two reasons...

winters here are summers in the southern hemisphere...most of my species originate in the south pacific...i try to create a natural light cyclye for them...

also, as daylight decreases here, and temperature drops...the extra lighting is also for esthetics...in my opinion, my tank looks best when there's not a whole lot of surrounding light...so i try and take advantage of the loss of daylight...

now...the real question is...do your fish know when it's supposed to be dark, and when it's suppossed to be light??? i dunno...i too would think they would adapt...but i'm not certain on this either...

but think of this...if the species did come from the south pacific...it's light there while it's dark here...so, if you are lighting from 12am to 12 pm...then you're actually accomadating for their "bio-clock". (if they have one)

[dzhuo]

I think they should be fine especially for the fish. They might be streed a little bit the first few days but I think they will adjust well after that. I am more worry about the coral as they are more sensitive to the change in their immedate env.

btw, I am planning to light my tank from noon-midnight, not from midnight-noon

thanks!
david

[phistio]

sorry for the misunderstanding...

again, i don't think there should be any problem...great question though...can't say i haven't thought about it myself...

[ssgibby]

I may be wrong, I think some spawn during lunar cycles.

[BigE]

I'd agree they adjust to the new lighting pattern after some time. I used to have a large hippo tang that knew the timing of the lights and about 15 mins. before lights out he would start swimming up and down the tank making waves on the surface of the water.

[sebae0]

i would have to say that there is some kind of biological clock there, but they adapt to our tanks and our lighting schedule. there are alot of corals that do spawn at specific lunar cycles and time of the year. seen that on discovery