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  #1  
Old 12/18/2007, 09:00 PM
xroads xroads is offline
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Why Blue Light?

Blue/Antinic light seems to make the colors pop more.

Why?

Has anyone tried using red, yellow, orange lights?
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  #2  
Old 12/18/2007, 10:20 PM
Scythanith Scythanith is offline
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Maybe some pigments flouresce on the UV (purple, blue, etc) side of the light spectrum, making them "pop"? Some/most (???) marine life cannot see colours on the IR (red, yellow, orange, etc) side of the spectrum since it's naturally filtered out by seawater. The deeper you go the less red light can penetrate into the water... that's why there are more red fish the deeper you go, they seem invisible to most animals since red light isn't represented well. So maybe for corals to stand out they need to utilize the blue spectrum...maybe?

At lest this will stir the pot.

Scott
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  #3  
Old 12/18/2007, 11:29 PM
REEF-n-Chicago REEF-n-Chicago is offline
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Everything Ive heard/read states that it is mostly for our pleasure only. The blue light makes everything look pretty! I do see what scythanith is saying about utilizing the blue spectrum and this might have some basis but I haven't heard much about it so.......
  #4  
Old 12/19/2007, 01:34 AM
steven_dean17 steven_dean17 is offline
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Scythanith is correct, the blue side of the spectrum is what is utilized by sea life. Red side is reflected off the surfface(for the most part) and this is why you get burned so qiuckly when your swimming.
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  #5  
Old 12/19/2007, 10:01 AM
Flint&Eric Flint&Eric is offline
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Quote:
Originally posted by steven_dean17
Scythanith is correct, the blue side of the spectrum is what is utilized by sea life. Red side is reflected off the surfface(for the most part) and this is why you get burned so qiuckly when your swimming.
being utilized and making colors pop are two different things i'd suggest reading dana's articles in advanced aquarist. there is a 3 part series that goes in depth on this subject...
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  #6  
Old 12/19/2007, 10:51 AM
A.T.T.R A.T.T.R is offline
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isnt it like plants. using the RED and the BLUE spectrum for growth
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  #7  
Old 12/19/2007, 10:33 PM
MCsaxmaster MCsaxmaster is offline
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Wow, okey dokey there's a tad of misinformation above.

The zooxanthellae in corals use chlorophyll a as their primary light harvesting pigment, but have a variety of other accessory pigments which absorb and transfer light energy to chl a. Chl a absorbs strongly in the blue and red portions of the light spectrum. Chl c2 used by dinoflagellates absorbs strongest in the blue/cyan and red/orange, extending the range a bit. They also have several other pigments that absorb between the red and blue (~650 - 500 nm). All of this has absolutely nothing to do with coral coloration unless you're talking about brownish shades. Zooxanthellae, with their various pigments absorbing in the above wavelengths, look brown.

Corals produce a variety of colorful proteins. None of these have anything to do with blocking UV and do not interact with UV at all. Please for the love of goodness do not equate coral pigments to UV light--there is no relation between the two. Some of these pigments likely protect zooxanthellae from too much light by absorbing it and either reflecting it or fluorescing. Others probably have a function completely separate from their effects on light, but nonetheless they just so happen to absorb/reflect/fluoresce.

Many fluorescent pigments are some derivation of green fluorescent protein, GFP, and GFP absorbs in the blue. If you change the structure of the protein a bit you can modify its absorption wavelengths and emission wavelengths. So, normal GFP absorbs in the blue and fluoresces green. Modify it a bit and it will absorb in the cyan and fluoresce yellow. Lots of non-fluorescent proteins are similar to GFP in structure too. If they absorb in the green (and reflect blue and red) they look purple. If they absorb in the green and red they look blue. If they absorb in the blue and green they look red. You get the idea.

Chris
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  #8  
Old 12/20/2007, 12:02 AM
barjam barjam is offline
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http://www.mbari.org/staff/ryjo/cosmos/Cabs.html

To visualize what MCsaxmaster is saying.
  #9  
Old 12/21/2007, 09:48 AM
killagoby killagoby is offline
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One of the coolest things I've ever seen was when I took a submarine ride in Hawaii. I have a tribal tatoo band around my arm that is red and black and around 3 inches thick. When we got down deep enough the water had filtered all of the red out of the color spectrum. My band looked solid black.
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  #10  
Old 12/24/2007, 11:50 AM
stony_corals stony_corals is offline
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Quote:
Originally posted by MCsaxmaster
Wow, okey dokey there's a tad of misinformation above.

The zooxanthellae in corals use chlorophyll a as their primary light harvesting pigment, but have a variety of other accessory pigments which absorb and transfer light energy to chl a. Chl a absorbs strongly in the blue and red portions of the light spectrum. Chl c2 used by dinoflagellates absorbs strongest in the blue/cyan and red/orange, extending the range a bit. They also have several other pigments that absorb between the red and blue (~650 - 500 nm). All of this has absolutely nothing to do with coral coloration unless you're talking about brownish shades. Zooxanthellae, with their various pigments absorbing in the above wavelengths, look brown.

Corals produce a variety of colorful proteins. None of these have anything to do with blocking UV and do not interact with UV at all. Please for the love of goodness do not equate coral pigments to UV light--there is no relation between the two. Some of these pigments likely protect zooxanthellae from too much light by absorbing it and either reflecting it or fluorescing. Others probably have a function completely separate from their effects on light, but nonetheless they just so happen to absorb/reflect/fluoresce.

Many fluorescent pigments are some derivation of green fluorescent protein, GFP, and GFP absorbs in the blue. If you change the structure of the protein a bit you can modify its absorption wavelengths and emission wavelengths. So, normal GFP absorbs in the blue and fluoresces green. Modify it a bit and it will absorb in the cyan and fluoresce yellow. Lots of non-fluorescent proteins are similar to GFP in structure too. If they absorb in the green (and reflect blue and red) they look purple. If they absorb in the green and red they look blue. If they absorb in the blue and green they look red. You get the idea.

Chris
RC should sticky this... This may reduce the "what bulbs to make my colors pop" or "how can I color up my corals"...
  #11  
Old 12/25/2007, 10:06 AM
reefmutt reefmutt is offline
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MCsaxmaster, that was very concise and informative.
One Question I have, though:
How is Zooxanthellae actually pronounced??
thanks!
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  #12  
Old 12/25/2007, 01:12 PM
greenbean36191 greenbean36191 is offline
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zoh-zan-thel-ee
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  #13  
Old 12/26/2007, 11:19 AM
samtheman samtheman is offline
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Quote:
Originally posted by MCsaxmaster
Wow, okey dokey there's a tad of misinformation above.

The zooxanthellae in corals use chlorophyll a as their primary light harvesting pigment, but have a variety of other accessory pigments which absorb and transfer light energy to chl a. Chl a absorbs strongly in the blue and red portions of the light spectrum. Chl c2 used by dinoflagellates absorbs strongest in the blue/cyan and red/orange, extending the range a bit. They also have several other pigments that absorb between the red and blue (~650 - 500 nm). All of this has absolutely nothing to do with coral coloration unless you're talking about brownish shades. Zooxanthellae, with their various pigments absorbing in the above wavelengths, look brown.

Corals produce a variety of colorful proteins. None of these have anything to do with blocking UV and do not interact with UV at all. Please for the love of goodness do not equate coral pigments to UV light--there is no relation between the two. Some of these pigments likely protect zooxanthellae from too much light by absorbing it and either reflecting it or fluorescing. Others probably have a function completely separate from their effects on light, but nonetheless they just so happen to absorb/reflect/fluoresce.

Many fluorescent pigments are some derivation of green fluorescent protein, GFP, and GFP absorbs in the blue. If you change the structure of the protein a bit you can modify its absorption wavelengths and emission wavelengths. So, normal GFP absorbs in the blue and fluoresces green. Modify it a bit and it will absorb in the cyan and fluoresce yellow. Lots of non-fluorescent proteins are similar to GFP in structure too. If they absorb in the green (and reflect blue and red) they look purple. If they absorb in the green and red they look blue. If they absorb in the blue and green they look red. You get the idea.

Chris
Why then do greenhouse growers who use non-UV blocking glazing, not have to use supplemental lightning? Those with UV blocking glazing utilize metal halides to get their corals to "color-up" before sale. Are both groups nuts or what?
  #14  
Old 12/26/2007, 10:36 PM
MCsaxmaster MCsaxmaster is offline
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Quote:
Originally posted by samtheman
Why then do greenhouse growers who use non-UV blocking glazing, not have to use supplemental lightning? Those with UV blocking glazing utilize metal halides to get their corals to "color-up" before sale. Are both groups nuts or what?
If it takes supplemental lighting in a greenhouse to get the corals to become colorful, then they aren't getting enough visible light. UV light has nothing to do with it. If folks with UV-blocking glass need more supplemental lighting than those without UV-shields then either the UV shield is blocking out a lot of light (e.g., frosting the glass) or it is coincidental. Most of these pigments absorb very little UV light, and there is no reason to think that they are produced to absorb any of the tiny amount of UV that they might. There simply is no relation between UV and the production or expression of pretty coral pigments. Unfortunately, thinking that there is some sort of relationship could certainly lead to a lot of dead corals overexposed to UV that did nothing but harm.

Chris
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  #15  
Old 12/27/2007, 12:17 PM
samtheman samtheman is offline
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Quote:
Originally posted by MCsaxmaster
If it takes supplemental lighting in a greenhouse to get the corals to become colorful, then they aren't getting enough visible light. UV light has nothing to do with it. If folks with UV-blocking glass need more supplemental lighting than those without UV-shields then either the UV shield is blocking out a lot of light (e.g., frosting the glass) or it is coincidental. Most of these pigments absorb very little UV light, and there is no reason to think that they are produced to absorb any of the tiny amount of UV that they might. There simply is no relation between UV and the production or expression of pretty coral pigments. Unfortunately, thinking that there is some sort of relationship could certainly lead to a lot of dead corals overexposed to UV that did nothing but harm.

Chris
Gosh,

Why not get with Anthony Calfo and straighten him out on this. He and other professionals who raise coral might have different experienc then you. How long have you been growing them?
  #16  
Old 12/27/2007, 02:56 PM
musty baby musty baby is offline
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MCsaxmaster, do you happen to know of literature stating that the presence/intensity of UV light has no effect on pigment production/concentration?
  #17  
Old 12/27/2007, 03:20 PM
barjam barjam is offline
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There have been multiple articles that state UV does very little.

http://www.advancedaquarist.com/2007/2/aafeature#h2

http://www.reefs.org/library/aquariu...98/1298_2.html

Quote:
Some hobbyists may be surprised that we did not include ultraviolet radiation (UV) as a factor. We have measured UV energy in dozens of aquaria and have reached the conclusion that high doses of UV energy do not play a role in making corals turn purple, red, blue, etc. We have noted that green fluorescent pigments may be produced under conditions of higher UV energy (about 30 microwatts per square centimeter per second).
Dana Riddle

MCsaxmaster isn't pulling this out of his hat, this is common knowledge in the hobby. Of course common knowledge isn't alway correct.
  #18  
Old 12/27/2007, 06:40 PM
MCsaxmaster MCsaxmaster is offline
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Quote:
Originally posted by samtheman
Gosh,

Why not get with Anthony Calfo and straighten him out on this. He and other professionals who raise coral might have different experienc then you. How long have you been growing them?
I've never spoken with Anthony about this. I'd be happy to talk with him and anyone about this topic though.

Experience growing corals does not make GFP-like proteins absorb significant amounts of UV. Experience in this case is completely meaningless. We are talking about a measurable physical property. Likewise, a person could have thousands of hours of flight time, but there is no way they are going to get a plane without wings to fly. A person can grow corals for decades, but that doesn't mean that GFP-like proteins are produced to deal with UV. They are not.

I've been growing corals for a bit more than 7 years now.

Chris
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  #19  
Old 12/27/2007, 06:46 PM
MCsaxmaster MCsaxmaster is offline
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Quote:
Originally posted by ryansholl
MCsaxmaster, do you happen to know of literature stating that the presence/intensity of UV light has no effect on pigment production/concentration?
Essentially all of it suggests that these proteins don't have a role in shielding against UV. They simply don't absorb much UV, hence they physically cannot work as a UV screen. The pigments also tend to vary with the amount of visible light, not necessarily UV, though the two may covary in the field.

The one exception may be GFP which looks to be related to reducing oxidative stress, and just so happens to fluoresce green. In other words, the fact that it interacts with light is a harmless side effect of its structure. GFP doesn't absorb significant amounts of UV, so it isn't acting as a UV shield, but it does tend to be expressed more in organisms undergoing oxidative stress and in many non-photosynthetic organisms. It was recently found in Amphioxis, for example.

See work by Salih, Dove, Kawaguti, etc.

Chris
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  #20  
Old 12/27/2007, 07:45 PM
samtheman samtheman is offline
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http://forum.marinedepot.com/Topic33101-13-4.aspx

The folks having trouble with browning corals did not do their homework. The problem is their sheeting or glazing (not to mention that apparent lack of understanding for principal mechanisms for coral pigmentation). There is no easy answer here either... their expectations in a GH are about as unrealistic as their expectations in aquaria when they mix corals from drastically different parts of the reef. There is no way you can expect a Euphylliid from 60ft that mfgs FPs to capture/retain weak light to be as colorful in the same tank as an Acroporid from 10 ft of water that mfgs FPs to reflect light. It may be impossible to get both to have optimal color under standardized lighting (UV blocked no less).

There is no secret why blue bubble corals turn brown under bright(er) aquarium lights... and why electric colored shallow water sps turn brown under weaker captive lighting (UV blocking and total light altering/reducing) sheeting for the GH in this case.

The matter is made worse by these cheap hobby greenhouses having really poor quality sheeting/glazing.

The folks with brown corals frankly got what they paid for (low investment in their education... low investment in their facility). I mean that literally... not as a slight (please don't take it out of context - to all).

.

Anthony Calfo
  #21  
Old 12/27/2007, 09:56 PM
billsreef billsreef is offline
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Quote:
There is no secret why blue bubble corals turn brown under bright(er) aquarium lights... and why electric colored shallow water sps turn brown under weaker captive lighting (UV blocking and total light altering/reducing) sheeting for the GH in this case.
The operative part of this is "total light altering/reducing". The zooxanthellae are brown. In the case of the bubble coral from a low light, i.e. little zoox's present, transferred to high light...the coral in brighter lighting is now growing more zoox's, hence the brown coloring. In the case of the "electric" sps, shallow water very bright lighting calls for a small numbers of zoox's. When it's placed in deeper water/lower light, it grows more zoox's to make up for the lower photosynthetic production of the individual zoox's.
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  #22  
Old 12/28/2007, 12:29 AM
MCsaxmaster MCsaxmaster is offline
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Quote:
Originally posted by samtheman
http://forum.marinedepot.com/Topic33101-13-4.aspx

The folks having trouble with browning corals did not do their homework. The problem is their sheeting or glazing (not to mention that apparent lack of understanding for principal mechanisms for coral pigmentation). There is no easy answer here either... their expectations in a GH are about as unrealistic as their expectations in aquaria when they mix corals from drastically different parts of the reef. There is no way you can expect a Euphylliid from 60ft that mfgs FPs to capture/retain weak light to be as colorful in the same tank as an Acroporid from 10 ft of water that mfgs FPs to reflect light. It may be impossible to get both to have optimal color under standardized lighting (UV blocked no less).

There is no secret why blue bubble corals turn brown under bright(er) aquarium lights... and why electric colored shallow water sps turn brown under weaker captive lighting (UV blocking and total light altering/reducing) sheeting for the GH in this case.

The matter is made worse by these cheap hobby greenhouses having really poor quality sheeting/glazing.

The folks with brown corals frankly got what they paid for (low investment in their education... low investment in their facility). I mean that literally... not as a slight (please don't take it out of context - to all).

.

Anthony Calfo
Indeed, some kinds of glass may be more or less ideal for use in a greenhouse intended to grow corals. Personally, I'd look for something with good light transmission and probably some ability to block UV.

Anthony is a wonderful aquarist and I have great respect for him, but the suggestion that UV intensity is important in promoting colorful pigment production in corals is simply incorrect. It seems he is making that suggestion here, and all I can say is that all the available data sharply disagree. These pigments aren't produced to deal with UV light nor does UV induce their production. Many fluorescent and non-fluorescent GFP-like proteins vary in production with incident PAR, not with UV. GFP doesn't show much correlation with light intensity or necessarily UV, and seems to have functions completely seperate from the fact that it interacts with light.

Chris
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Last edited by MCsaxmaster; 12/28/2007 at 12:37 AM.
  #23  
Old 12/28/2007, 12:34 AM
MCsaxmaster MCsaxmaster is offline
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Quote:
Originally posted by billsreef
The operative part of this is "total light altering/reducing". The zooxanthellae are brown. In the case of the bubble coral from a low light, i.e. little zoox's present, transferred to high light...the coral in brighter lighting is now growing more zoox's, hence the brown coloring. In the case of the "electric" sps, shallow water very bright lighting calls for a small numbers of zoox's. When it's placed in deeper water/lower light, it grows more zoox's to make up for the lower photosynthetic production of the individual zoox's.
Zoox. density shows no significant variation over a large range of depths (and hence light intensity). Zoox. density tends to vary with N availability, not light availability. Instead, in lower light the zoox. produce more and/or larger photosystems, so the zoox. that are there appear darker. A coral in shallow water and another colony of the same species in deep water will tend to have the same zoox. density in the tissue, but the pigment density (and hence pigment per zooxanthella) will be higher in deeper water. At all but extremely low light intensities (light intensities below which zoox. can survive) an increase in light should lead to a reduction of pigment density, not an increase.

Chris
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  #24  
Old 12/28/2007, 11:43 AM
samtheman samtheman is offline
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So all the money spent on non-UV blocking glazing is a hoax then?
  #25  
Old 12/28/2007, 06:00 PM
MCsaxmaster MCsaxmaster is offline
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I couldn't say. I can say that the UV is not benefitting a person by causing the corals to produce more colorful proteins though (possibly with the exception of GFP, but that isn't even straightforward).

Chris
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