Are "Low Light Corals" A Myth?

[Donovan Joannes]

So is that why my shrooms looked like....

I am getting the same problem... Wait!. It is not a problem. Congrats, you have bouncy yuma. Thanks to your light. :D

 

[saltyfilmfolks]

After watching Dana Riddle's video regarding the porites in the tide pool, I'm thinking "high" light corals don't exist.

It might be worth while to watch more documentarys and look at reefs where corals come out of the water. Or are in just a couple feet of water and stay submerged.
One of my questions on high light corals is , clams that live at in only a few feet of water share the same zooalnthelene algaes, yet don't appear to have a photo inhibition point. But that's for another thread.

 

[Nano sapiens]

I had the same thing with a pink yuma. Was neat until it finally had enough and turned into a blob of brown goo...so beware of too much light :)

 

[Nano sapiens]

It might be worth while to watch more documentarys and look at reefs where corals come out of the water. Or are in just a couple feet of water and stay submerged.
One of my questions on high light corals is , clams that live at in only a few feet of water share the same zooalnthelene algaes, yet don't appear to have a photo inhibition point. But that's for another thread.

The relatively thick clam mantle and pigments may play a protective role...or so it has been theorized.

 

[saltyfilmfolks]

The relatively thick clam mantle and pigments may play a protective role...or so it has been theorized.

I think they should send US to go look.

 

[Donovan Joannes]

I had the same thing with a pink yuma. Was neat until it finally had enough and turned into a blob of brown goo...so beware of too much light :)

I found out my mushrooms will detached itself and move somewhere else with the flow if they are not happy. Some will move a couple of inches away from light as well.

I have 3 different blasto that acting the same (detaching itself or the next offspring doesn't stick to anything but simply waving to the waves until it separated from mother colony).

Too intense might kill them, but slightly higher should be okay.

Edit: Picture showing babies of yuma from single mother. They seems to like the higher lights.

 

[hart24601]

The relatively thick clam mantle and pigments may play a protective role...or so it has been theorized.

And they can close when they get enough light. I kept blue Maxima's for years under quite intense led light and by the end of the photoperiod they gradually closed unless I ran the lights at lower intensity.

 

[hart24601]

I would suspect surface area/volume ratio starts coming into play as well for nutrients/light and heat absorption and dispersion/flow tolerance. How much more volume (flesh so to speak) dose a single poly of lobo, acan, trachy have compared to an acro per polyp? What does this do to the above nutrients/light and heat absorption and dispersion/flow tolerance? These are questions we do not know, but I wouldn't be shocked if there is relation to light tolerance before damage occurs.

I forgot to to add when I posted this that extra light energy is dissipated as heat. It's one reason I suggest we talk about the flow past a particular coral when we talk about par and bleaching.

I suspect "meaty" coral with a lot of tissue volume (or mass) simply are unable to manage heat as well compared to a coral like acros that have very little tissue compared to their surface area. Which makes it harder for those fleshy corals to handle intense lighting.

 

[saltyfilmfolks]

I forgot to to add when I posted this that extra light energy is dissipated as heat. It's one reason I suggest we talk about the flow past a particular coral when we talk about par and bleaching.

I suspect "meaty" coral with a lot of tissue volume (or mass) simply are unable to manage heat as well compared to a coral like acros that have very little tissue compared to their surface area.

THAT is an interesting point.

 

[Dana Riddle]

Just as some plants prefer 'shade' or 'sun', different zooxanthellate clades have preferences for the amount of light they receive - it has to do with their ability to process absorbed photons. Many point to corals being exposed at low tide to prove corals can thrive in high light environments. The truth of the matter is that these corals are in a stressful environment and are coping as best they can in a number of ways (protective xanthophylls, reflective and/or fluorescent pigments, mycosporine amino acids. etc.) Ironically, these photos often show Acropora specimens that contain Clade C zooxanthellate which have relatively low photosaturation points. There is a high fidelity in the coral/zoox relationship and these captive dinoflagellates have a limited ability to adapt (that is, process photons.) During my 18 years in Hawaii, I studied the reefs there and realized many corals/zoox will tolerate high light but must be able to adequately photosynthesize during periods of rain/cloudiness and high surf when the ocean looks like milk due to entrapped air bubbles, brown due to terrestrial runoff during heavy rain, high turbidity from suspended particles (marine snow), and so on.

 

[Duraticate]

Are your shrooms spreading or staying like one frag?

They spread

 

[Duraticate]

So is that why my shrooms looked like....

Sadly they didnt stay that way....

 

[Dana Riddle]

Energy dissipation is via non-radiant means, so it really isn't heat.

 

[GoVols]

Sadly they didnt stay that way....[/ATTACH]

:(

 

[Scott.h]

Just as some plants prefer 'shade' or 'sun', different zooxanthellate clades have preferences for the amount of light they receive - it has to do with their ability to process absorbed photons. Many point to corals being exposed at low tide to prove corals can thrive in high light environments. The truth of the matter is that these corals are in a stressful environment and are coping as best they can in a number of ways (protective xanthophylls, reflective and/or fluorescent pigments, mycosporine amino acids. etc.) Ironically, these photos often show Acropora specimens that contain Clade C zooxanthellate which have relatively low photosaturation points. There is a high fidelity in the coral/zoox relationship and these captive dinoflagellates have a limited ability to adapt (that is, process photons.) During my 18 years in Hawaii, I studied the reefs there and realized many corals/zoox will tolerate high light but must be able to adequately photosynthesize during periods of rain/cloudiness and high surf when the ocean looks like milk due to entrapped air bubbles, brown due to terrestrial runoff during heavy rain, high turbidity from suspended particles (marine snow), and so on.

How extreme of variations occur from one species of acropora to another with this? Is there a way for us to identify the clade c, or is it only trial by error?

 

[Dana Riddle]

See here for a listing of zooxanthellate clades by coral genus hosts. http://www.advancedaquarist.com/2016/2/aafeature

 

[saltyfilmfolks]

Just as some plants prefer 'shade' or 'sun', different zooxanthellate clades have preferences for the amount of light they receive - it has to do with their ability to process absorbed photons. Many point to corals being exposed at low tide to prove corals can thrive in high light environments. The truth of the matter is that these corals are in a stressful environment and are coping as best they can in a number of ways (protective xanthophylls, reflective and/or fluorescent pigments, mycosporine amino acids. etc.) Ironically, these photos often show Acropora specimens that contain Clade C zooxanthellate which have relatively low photosaturation points. There is a high fidelity in the coral/zoox relationship and these captive dinoflagellates have a limited ability to adapt (that is, process photons.) During my 18 years in Hawaii, I studied the reefs there and realized many corals/zoox will tolerate high light but must be able to adequately photosynthesize during periods of rain/cloudiness and high surf when the ocean looks like milk due to entrapped air bubbles, brown due to terrestrial runoff during heavy rain, high turbidity from suspended particles (marine snow), and so on.

Hi Dana!
I'm Jason. Well thank you again for connecting the dots for me.
Not a myth.
So many folks in the hobby claim both sides of the argument equally passionately with only anecdotal evidence. Generally a mis ID of where the corals have come from.

See here for a listing of zooxanthellate clades by coral genus hosts. http://www.advancedaquarist.com/2016/2/aafeature

I've read this before quite some time ago.

Much like Randy Farleys articles, as I go further into the hobby a lot of what ive read and learned begins to make a bit more sense as the dots are connected.
Thanks.

QUOTE="Dana Riddle, post: 3847144, member: 18120"]Energy dissipation is via non-radiant means, so it really isn't heat.[/QUOTE]
So it's energy is converted or used for metabolic processes then?

 

[mcarroll]

S0, what is the mechanism the would make a coral ONLY do well in lower light?

Good question.

But hypothetically a coral that's completely photo-adapted to low light will only do well at low light. Depending on actual circumstances that's either mortally true or not true at all. ;)

So maybe "photo-adaptation" qualifies as your answer?

Or...

• Branching morphology is supposed to reduce sun exposure, allowing those corals to compete better under higher irradiance levels.

• By extension, I think one could possibly assert that non-branching coral morphologies are better suited to lower irradiance levels.

All Corals Are Low-Light Corals!
To me it seems like many folks tend to want to blast their corals with all the photons they can muster.

Eco-evolutionarily, corals are predators from the deep dark deep. The only reason they come near the surface of the ocean is because they've been hijacked by a photosynthetic parasite symbiont – not because they're necessarily good at being near the surface. Some corals are more good – some are less good. ;) But all corals I've seen data for are able to get all their light needs from VERY LOW LEVELS of irradiance – above those low levels it's all tolerance and coping for them. Stress.

I haven't kept many types at home, but I do keep a low-light stony coral tank (around 15,000 lux over a 19" deep tank) and can attest my experience with those. I haven't found any corals to have trouble so far.

Are There Any High-Light Corals?
I would suggest that the myth is the "high light coral". In bright light, there are only levels of coping with corals – it doesn't seem natural to them. Some are quite good at coping – amazingly good at it in some cases – but it's still coping.

Clams on the other hand....no such thing as a low-light clam AFAIK. They don't seem to be familiar with photo-inhibition at all, even under extremely high irradiance levels. They don't seem stressed by light. These are true shallow-water, high-light creatures!

 

[Scott.h]

Good question.

But hypothetically a coral that's completely photo-adapted to low light will only do well at low light. Depending on actual circumstances that's either mortally true or not true at all. ;)

So maybe "photo-adaptation" qualifies as your answer?

Or...

• Branching morphology is supposed to reduce sun exposure, allowing those corals to compete better under higher irradiance levels.

• By extension, I think one could possibly assert that non-branching coral morphologies are better suited to lower irradiance levels.

All Corals Are Low-Light Corals!
To me it seems like many folks tend to want to blast their corals with all the photons they can muster.

Eco-evolutionarily, corals are predators from the deep dark deep. The only reason they come near the surface of the ocean is because they've been hijacked by a photosynthetic parasite symbiont – not because they're necessarily good at being near the surface. Some corals are more good – some are less good. ;) But all corals I've seen data for are able to get all their light needs from VERY LOW LEVELS of irradiance – above those low levels it's all tolerance and coping for them. Stress.

I haven't kept many types at home, but I do keep a low-light stony coral tank (around 15,000 lux over a 19" deep tank) and can attest my experience with those. I haven't found any corals to have trouble so far.

Are There Any High-Light Corals?
I would suggest that the myth is the "high light coral". In bright light, there are only levels of coping with corals – it doesn't seem natural to them. Some are quite good at coping – amazingly good at it in some cases – but it's still coping.

Clams on the other hand....no such thing as a low-light clam AFAIK. They don't seem to be familiar with photo-inhibition at all, even under extremely high irradiance levels. They don't seem stressed by light. These are true shallow-water, high-light creatures!

I guess it would depend on what one would consider high light. I would consider low light to be in the 50-75 par range, medium light to be 150-200ish, high 250-300, anything above that ultra high. Considering if you walk outside with a par meter, normal light would be off the chart for what we'd consider high light.

I'd also have to say that when a coral is stressed it may bring out pigments that we find attractive, not necessarily best for the coral.

All my sps corals seem to do quite well around 200-250 par. Some Zoe's and acans pinch or appear too light in color, imo even at the bottom under these 200-250 mid tank conditions. Then some non sps have drifted under rocks with what appear to be an unreadable amount of light, but look really good. Then I have 2 or 3 sps that appear to need more light then what I'm giving them at the peak part of my rock work. It makes me wonder if this is based on what the coral prefers, or based on what I think looks good.

 

[Dana Riddle]

Shallow water Porites in Hawaiian tide pools are maxed out photosynthetically by early morning. These corals contain the light and heat tolerant zoox clade C15.) However, these corals are stunted and rarely get more than a foot or so across, while their deeper water brothers (technically incorrect because they are hermaphroditic ;)) can be tens of feet across. The ability to tolerate high light has to do with their zoox's abilities to process photons, manufacture protective xanthophylls, mycosporine-like amino acids for UV protection, and so on. Of the tens of thousands of PAR measurements I've had the honor of making in tanks across the country, I've seen only two where the corals were receiving light intensity that they would naturally experience in a Hawaiian tide pool at about 9 am during a cloudless summer day.