can corals tell time?

rossthefishman · 07/22/2007, 08:21 PM

Today when i came home at around eight O'clock, my polyps were already fully retracted, and my rics were folding up. My lights usually go off before this time, but in this case, they were still on, yet the corals were still closed. Can they tell that it should be night time? what's your opinion?

LobsterOfJustice · 07/22/2007, 08:23 PM

Most definantly. They get used to a schedule and learn to anticipate regular events like a light cycle or feeding.

acrodave · 07/22/2007, 08:25 PM

fish will do the same

IslandCrow · 07/22/2007, 09:09 PM

Quote:

Most definantly. They get used to a schedule and learn to anticipate regular events like a light cycle or feeding.

What are you basing this statement on? I'm not saying you're wrong, but corals don't have a brain, so they don't really "get used" to "learn" anything. If I turn my lights off in the middle of the day, my Caulastrea and Trachyphyllia extend their feeding tentacles, so I'd say it's simply a response to the change in lighting for them, or possibly the reduction in activity from their zooxanthallae.

What type of corals are we talking about here? I can see them getting into a certain biorhythm with a regular lighting schedule, and I think that's what LobsterofJustice is probably getting at, but I think you ask a really good question, and I'm not so sure all corals are the same on that account.

Iron Maiden · 07/22/2007, 09:27 PM

recently my digital timer on my lights bit the dust. I had to manually turn my 10k's on and off. Most of the SP's in the tank still reacted to the timer schedule. They would retract on time whether I had turned the lights off or not.

ACBlinky · 07/22/2007, 09:51 PM

I think corals definitely become accustomed to a set photoperiod. They'll anticipate lights on and off, just as the fish will - I had a wrasse that used to find a place to sleep every night just before lights-out, and I notice that corals will retract at the same time each night even if the lights are accidentally left on (if the timers fail for instance). They may not have brains, but they do seem to react to events that occur at the same time every day.

UrbanSage · 07/22/2007, 10:45 PM

Quote:

Originally posted by IslandCrow
If I turn my lights off in the middle of the day, my Caulastrea and Trachyphyllia extend their feeding tentacles, so I'd say it's simply a response to the change in lighting for them, or possibly the reduction in activity from their zooxanthallae.

True, but backwards.
The curious part is when all the corals, clams and fish get ready for bed 10 minutes before lights off every day.
Maybe if we replace "learn" with "adapt"?

rkcca · 07/22/2007, 10:59 PM

Fish and corals absolutely know the light schedule when on timers. When I had large leathers and lots of LPS, they would start retracting just before lights out. It was really a dramatic change.

cloak · 07/23/2007, 01:13 AM

High tide, low tide. Corals without water.

dt90gt · 07/23/2007, 01:16 AM

I can look at my tanks at night, and figure that it is about 5-10 minutes from the lights turning off based on the look of the corals and all the fish hiding in the rockwork preparing to sleep. No dusk dawn setup, just 2x250w lights on and off.

Frick-n-Frags · 07/23/2007, 04:47 AM

Quote:

Originally posted by dt90gt
I can look at my tanks at night, and figure that it is about 5-10 minutes from the lights turning off based on the look of the corals and all the fish hiding in the rockwork preparing to sleep.

right on, my animals give the "10 minutes to store closing" heads up so you can get out of the tank before lights out.

whatever clock mechanism they have, it works really well once they get into a groove.

rossthefishman · 07/23/2007, 05:15 AM

It's polyps and shrooms doing it in my tank. But my clowns do the same thing, about ten minutes prior to lights out, you'll see them in the corner next to my mag float ready to sleep =).

CKreef · 07/23/2007, 06:35 AM

Watchmen gobies can tell time

Tang Salad · 07/23/2007, 07:08 AM

I'd be curious to know which biological mechanism within corals is able to keep track of time.

Any guesses?

hankthetank · 07/23/2007, 07:35 AM

Corals don't know anything.They do not possess the nervous system required for knowledge.They can adapt to stimuli(circadian rythym)as can plants.Does a coral know what time the lights will come on or does it adapt to the schedule imposed by the aquarist?If they could really tell time why would it take them so long to adapt if you change the light cycle?Wouldn't they change the next day to optimize their survival?Come on people!

skeeter-doc · 07/23/2007, 07:45 AM

Quote:

Originally posted by CKreef
Watchmen gobies can tell time

funny stuff!

rbursek · 07/23/2007, 12:59 PM

I do not know about time, but my LPS's sure know when the full moon is coming, they get huge starting about a week before.

IslandCrow · 07/23/2007, 08:46 PM

I don't know if any actual research has been done into this. I do agree that certain corals get into a certain "rhythm". I think the question goes deeper than that. I run my lights 10:00 A.M. to 10:00 P.M. That hardly mirrors the environment where they were first spawned. Something has to trigger the response to the light, and I don't think comparing them to fish is very accurate. A fish can anticipate, and I guess certain watchman gobies can even tell time. Corals, however cannot see (as far as we know), so again I go back to my guess that it has to do with the zooxanthallae either directly or indirectly.

By the way, does anyone have any non photosynthetic corals that react in one way or another to a lighting schedule? I don't own any myself.

rossthefishman · 07/24/2007, 05:35 AM

But if it is in fact a reaction due to less activity of the zooxanthallae, then we would not be seeing any change in activity before a few minutes after lights out. But many people notice a change in their corals well before the lights go out, when the zooxanthallea would still be active. can they by chance have some kind of memory? or they simply get enough light for the day, and decide to retract?

Frick-n-Frags · 07/24/2007, 07:05 AM

they definitely have a programmable, hate to call it memory, time scheduling mechanism.

think about this: nobody runs their tank lights the identical amount of time, yet all the animals figure it out(or become impressed with it somehow - no they can't "think", "tell" "feel" come on, let's get beyond the obvious here)

Scuba_Steve · 07/24/2007, 07:18 AM

Isnt nature a wonderful thing? Sometimes science just cant explain certain things (Im not saying the reason for this in particular hasnt been proven somewhere).

Subliminal · 07/24/2007, 07:48 AM

At 8:30 my clowns put on their PJs and nessel into their BTA. I read them a story, and they go to sleep.

It's all very exciting.

07/22/2007, 08:21 PM	#1
rossthefishman Registered Member Join Date: Aug 2006 Location: Bluefield West Virginia Posts: 175	can corals tell time? Today when i came home at around eight O'clock, my polyps were already fully retracted, and my rics were folding up. My lights usually go off before this time, but in this case, they were still on, yet the corals were still closed. Can they tell that it should be night time? what's your opinion?

07/22/2007, 08:23 PM	#2
LobsterOfJustice Recovering Detritophobe Join Date: Jan 2004 Location: Cary, NC Posts: 7,443	Most definantly. They get used to a schedule and learn to anticipate regular events like a light cycle or feeding. __________________ If it's worth doing, it's worth doing right. I remember when zoanthids were called things like "green" and "orange" and not "reverse gorilla nipple." Current Tank Info: 180g reef with all the bells and whistles

07/22/2007, 08:25 PM	#3
acrodave REEF NERD Join Date: Nov 2006 Location: maryville tn-- work in knoxville Posts: 4,187	fish will do the same __________________ Peace,Dave Superman puts on Tim Tebow pajamas when he goes to bed The Heisman as a sophomore nuff said Less technology more biology Tattoos are the only art you can take to the grave Current Tank Info: 26gal bow,20gal mantis tank/fuge150wHQI,20k AB Seio 620 maxijet1200x's 2 on a wave maker. all sps

07/22/2007, 09:27 PM	#5
Iron Maiden Registered Member Join Date: May 2007 Location: Texas Posts: 79	recently my digital timer on my lights bit the dust. I had to manually turn my 10k's on and off. Most of the SP's in the tank still reacted to the timer schedule. They would retract on time whether I had turned the lights off or not. __________________ "Here's to you Mr. way too proud of Texas guy". Current Tank Info: 125gal reef with 2 yellow tangs, 1 skunk clown, 7 lemon damsels, 4 pink smiths damsels, 1 scooter blenny, 1 banded coral shrimp, sally lightfoot, 2 hermit crabs, 4 gigantic turbos, 2 anemoneis, and corals.

07/22/2007, 09:51 PM	#6
ACBlinky Premium Member Join Date: May 2005 Location: Peterborough, ON, Canada Posts: 4,954 Blog Entries: 20	I think corals definitely become accustomed to a set photoperiod. They'll anticipate lights on and off, just as the fish will - I had a wrasse that used to find a place to sleep every night just before lights-out, and I notice that corals will retract at the same time each night even if the lights are accidentally left on (if the timers fail for instance). They may not have brains, but they do seem to react to events that occur at the same time every day. __________________ "The cure for anything is salt water: sweat, tears, or the sea." - Isak Dinesen Current Tank Info: 150g mixed reef, 30g sump/refugium, LED lighting, 100lbs LR, coral beauty, flame angel, blue & yellow tangs, gobies, damsels, 6-line wrasse, lawnmower blenny, dottyback, clown pair, rabbitfish, shrimp, crabs, CUC.

07/22/2007, 10:59 PM	#8
rkcca Registered Member Join Date: Jan 2007 Location: OC, So Cal Posts: 236	Fish and corals absolutely know the light schedule when on timers. When I had large leathers and lots of LPS, they would start retracting just before lights out. It was really a dramatic change.

07/23/2007, 01:13 AM	#9
cloak Moved On Join Date: Jul 2000 Location: Stockton, CA Posts: 14,854	High tide, low tide. Corals without water.

07/23/2007, 01:16 AM	#10
dt90gt Registered Member Join Date: Apr 2005 Location: Huntington Beach Posts: 134	I can look at my tanks at night, and figure that it is about 5-10 minutes from the lights turning off based on the look of the corals and all the fish hiding in the rockwork preparing to sleep. No dusk dawn setup, just 2x250w lights on and off.

07/23/2007, 05:15 AM	#12
rossthefishman Registered Member Join Date: Aug 2006 Location: Bluefield West Virginia Posts: 175	It's polyps and shrooms doing it in my tank. But my clowns do the same thing, about ten minutes prior to lights out, you'll see them in the corner next to my mag float ready to sleep =).

07/23/2007, 06:35 AM	#13
CKreef Registered Member Join Date: Jan 2006 Location: Ashland City Posts: 1,614	Watchmen gobies can tell time

07/23/2007, 07:08 AM	#14
Tang Salad Algae skeptic Join Date: Oct 2006 Location: 78702 Posts: 3,098	I'd be curious to know which biological mechanism within corals is able to keep track of time. Any guesses? __________________ Your algae is not special. Current Tank Info: TBD ADA 120-P SPS NLPS

07/23/2007, 07:35 AM	#15
hankthetank Moved On Join Date: Jun 2007 Posts: 161	Corals don't know anything.They do not possess the nervous system required for knowledge.They can adapt to stimuli(circadian rythym)as can plants.Does a coral know what time the lights will come on or does it adapt to the schedule imposed by the aquarist?If they could really tell time why would it take them so long to adapt if you change the light cycle?Wouldn't they change the next day to optimize their survival?Come on people!

07/23/2007, 12:59 PM	#17
rbursek Moved On Join Date: Jun 2006 Location: germantown,wi Posts: 2,339	I do not know about time, but my LPS's sure know when the full moon is coming, they get huge starting about a week before.

07/23/2007, 08:46 PM	#18
IslandCrow Reef Monkey Join Date: Sep 2005 Location: Rockledge, Fl Posts: 5,759	I don't know if any actual research has been done into this. I do agree that certain corals get into a certain "rhythm". I think the question goes deeper than that. I run my lights 10:00 A.M. to 10:00 P.M. That hardly mirrors the environment where they were first spawned. Something has to trigger the response to the light, and I don't think comparing them to fish is very accurate. A fish can anticipate, and I guess certain watchman gobies can even tell time. Corals, however cannot see (as far as we know), so again I go back to my guess that it has to do with the zooxanthallae either directly or indirectly. By the way, does anyone have any non photosynthetic corals that react in one way or another to a lighting schedule? I don't own any myself. __________________ All opinions in the above message should be taken with 35 ppt salt. -Mike C. Current Tank Info: I have a reef screen saver on my phone, does that count?

07/24/2007, 05:35 AM	#19
rossthefishman Registered Member Join Date: Aug 2006 Location: Bluefield West Virginia Posts: 175	But if it is in fact a reaction due to less activity of the zooxanthallae, then we would not be seeing any change in activity before a few minutes after lights out. But many people notice a change in their corals well before the lights go out, when the zooxanthallea would still be active. can they by chance have some kind of memory? or they simply get enough light for the day, and decide to retract?

07/24/2007, 07:05 AM	#20
Frick-n-Frags Registered Member Join Date: Oct 2000 Location: north central OH Posts: 10,740	they definitely have a programmable, hate to call it memory, time scheduling mechanism. think about this: nobody runs their tank lights the identical amount of time, yet all the animals figure it out(or become impressed with it somehow - no they can't "think", "tell" "feel" come on, let's get beyond the obvious here) __________________ Only Dead fish swim with the current. Current Tank Info: 2 50 gal tanks, sump, still BB

07/24/2007, 07:18 AM	#21
Scuba_Steve Premium Member Join Date: Mar 2005 Location: Pooler, Ga Posts: 1,342	Isnt nature a wonderful thing? Sometimes science just cant explain certain things (Im not saying the reason for this in particular hasnt been proven somewhere). __________________ 40g DIY AIO. DT Size is 27"x18"x17" SCA-301 skimmer, DIY ATS 4"x4" 1 cube setup, Ocean Revive 120w LED, Quiet One 3000, Jager 150w TBS Rock

07/24/2007, 07:48 AM	#22
Subliminal Registered Member Join Date: Mar 2007 Location: Princeton, NJ Posts: 322	At 8:30 my clowns put on their PJs and nessel into their BTA. I read them a story, and they go to sleep. It's all very exciting.