Light spectrums for corals

[Dana Riddle]

FWIW, here is a graph from one of Dana's articles showing the light spectrum at 10 feet deep in sea water. There's much more green, orange and red than there is in the spectrum from a typical light fixture.

The chart shows light transmission in the clearest of any seawater (Jerlov Type I Oceanic) and likely that seen off the west coast of the Big Island of Hawaii. Later in this thread I posted light transmission in the clearest of 'green' Coastal water (Jerlov Type I Coastal; probably that off the Florida coastal where nutrient loading from runoff, rivers and streams, septic tanks and water reclamation facilities occurs.)

 

[sde1500]

And a Table showing photo-saturation points for various corals. The deeper the depth, the lower the Saturation Point. And then we must account for spectral quality. As aquarists, we want simple exact answers. Unfortunately, there are none. All this info demonstrates the incredible adaptability of zooxanthellae.
Saturation
Acropora divaricata 77
Acropora granulosa 102
Pavona varians 110
Montipora capitata 135
Acropora nobilis 180
Montipora tuberculosa 180
Acropora millepora 190
Montipora danae 'Superman' 200
Porites cylindrica 200
Stylophora pistillata 200
Pocillopora damicornis 225
Acropora millepora 230
Porites lobata 250
Acropora cervicornis 281
Montipora tuberculosa 300
Acropora microphthalma 300
Stylophora pistillata 300
Acropora nobilis 310
Pocillopora eydouxi 323
Acropora cervicornis 331
Acropora formosa 340
Acropora gemmifera 340
Acropora digitifera 387
Porites lutea 400
Sinularia densa ~207
Tridacna maxima >600

Not sure I get what I am looking at here, could you explain?

 

[Bpb]

Not sure I get what I am looking at here, could you explain?

I believe he calculated the minimum par level for photo-saturation to occur within samples of those given species.

Dana, correct me if I’m wrong, but there is a window of higher par levels after saturation before inhibition occurs right? And furthermore would nutrient and flow levels, as well as longer term acclimation to different light levels shift those characteristics up or down for those given species? Or is that a genetic predisposition that is fairly unchangable?

 

[Dana Riddle]

I believe he calculated the minimum par level for photo-saturation to occur within samples of those given species.

Dana, correct me if I’m wrong, but there is a window of higher par levels after saturation before inhibition occurs right? And furthermore would nutrient and flow levels, as well as longer term acclimation to different light levels shift those characteristics up or down for those given species? Or is that a genetic predisposition that is fairly unchangable?

Bpd - Yes, you are correct, the Saturation Point (where increasing light intensity does not increase the rate of photosynthesis) is below that of Dynamic Photoinhibition (where the Xanthophyll Cycle offers a 'pressure relief valve to prevent damage to the photosynthetic apparatus). The point where Chronic Photoinhibition occurs is higher still - protective devices found in Dynamic Photoinhibition are overwhelmed and damage to the photosynthetic mechanisms occurs. The zoox/coral must them expend energy to make repairs and if repair does not keep up with damage, the coral eventually bleaches and dies.
The Saturation Point is higher in shallow water and lower in deeper water. Some zoox types (clades) are highly adaptable to light intensity and are 'weedy' (Clades C1, C2, and C15 are good examples, and are called 'generalists'). Some are more tolerant of high temperatures (that is, Symbiodinium thermophilum.) On the other hand, some zooxanthellae clades have very narrow light requirements and do not adapt well to light fields outside their niche environments (such as the Hawaiian coral Pocillopora molokensis.) These types are called 'specialists.' I has been proven that water motion can increase the rate of photosynthesis (at least in a Porites species.) Increased alkalinity can have a similar effect.

 

[sde1500]

Thanks guys that makes sense.

 

[Miguel Medina]

Much better in the 490nm range, it's almost tolo that sells like cyan

 

[Miguel Medina]

Much better in the 490nm range, it's almost tolo that sells like cyan

 

[Belgian Anthias]

Does a coral growing in nature at 0-3m contains the same pigments for fotosynthesis as a coral of the same family growing at 5-10 m? Does a coral contains only the pigments needed for the lightconditions where it has grows up or can it be replaced to other lightconditions needing other pigments. How important are the lightconditions where it has grown up for the survival in an aquarium and for the light conditions wich must be provided? Light intensity and spectrum. Does zooxanthella within corals adjust easily to different light conditions? Are the zooxanthella ( dinoflaggelates) typical for the coral. It is assumed the symbiont takes place in the egg phase. This may be the reason why the presence of some species of coral is linked with specific depth and light conditions.
The spectrum is important for potosynthesis. As is the lightintensity. To much light within the specimen specific spectrum will limit growth.

Zooxanthella may contain chlorophyll a and chlorophyll c, as well as the dinoflagellate pigments peridinin and diadinoxanthin. ( ref Wikipedia) But I do not know ( yet) if zooxantella developping unther a specific narrow spectrum are able to synhtesise all different proteïns for the pigments chlorofyl, carotenoïden en fycobilinen .

What narrow spectrum is best for a typical coral may be difficult. As chlorphyl is present in most dinoflaggellates ( sensetive for bleu and red) Spectrum wise I would go for broad-spectrum shifting to the bleu ( dept 3-5m). This way the color of the fish look as if you where snorkling above the reef. And light wise all creatures may be maintained happy.

 

[Dana Riddle]

Does a coral growing in nature at 0-3m contains the same pigments for fotosynthesis as a coral of the same family growing at 5-10 m? Does a coral contains only the pigments needed for the lightconditions where it has grows up or can it be replaced to other lightconditions needing other pigments. How important are the lightconditions where it has grown up for the survival in an aquarium and for the light conditions wich must be provided? Light intensity and spectrum. Does zooxanthella within corals adjust easily to different light conditions? Are the zooxanthella ( dinoflaggelates) typical for the coral. It is assumed the symbiont takes place in the egg phase. This may be the reason why the presence of some species of coral is linked with specific depth and light conditions.
The spectrum is important for potosynthesis. As is the lightintensity. To much light within the specimen specific spectrum will limit growth.

Zooxanthella may contain chlorophyll a and chlorophyll c, as well as the dinoflagellate pigments peridinin and diadinoxanthin. ( ref Wikipedia) But I do not know ( yet) if zooxantella developping unther a specific narrow spectrum are able to synhtesise all different proteïns for the pigments chlorofyl, carotenoïden en fycobilinen .

What narrow spectrum is best for a typical coral may be difficult. As chlorphyl is present in most dinoflaggellates ( sensetive for bleu and red) Spectrum wise I would go for broad-spectrum shifting to the bleu ( dept 3-5m). This way the color of the fish look as if you where snorkling above the reef. And light wise all creatures may be maintained happy.

There are a few papers concerning photopigment ratios according to depth (Titlyanov comes to mind.) Production of protective agents (mycosporine-like amino acids for UV and xanthophylls for general protection against light intensity) vary according to environmental parameters. Some zooxanthellae clades are highly adaptable to low and high light intensity (generalist clades) while other are not (specialist clades.) Thanks for your comments and references!

 

[Belgian Anthias]

There is a huge diversity of symbiodinium ( zooxantelle) and each are specialized in doing what they do best. Corals addapt to a changing environment better and faster as most would expect due to the big diversity of bacteria, archaea, dinoflagellates, fungi, living in the coral holoboint. Also to light. As corals are bentic the diversity must be present. To what extent this diversity is present in a closed aquarium system I do not know. But the light must not only serve corals, light is inportant for all organismes living in the aquarium. What they all have in commen is, they do not like to much light. The intensity of light is in relation to the spectrum.
White light may be made by full spectrum. For me the choice would be full spectrum with a shift to blue. ( 3-5m) One may create different light zones, simmulate different dept zones. One can not simmulate nature.
How one wants things to look? Simulating nature at a dept of 20m will result in verry pale blueish colors.
What light or spectrum is best for corals? Think about all other organisms needed to keep the corals healthy.

A lot of reasearch was done recently about the coral holobiont and zooxanthellae, using new and better methods. An example:
Coral dinoflagellates are of the genus Symbiodinium, but there are many different types and clades that differ in such a way that they perform some functions better and or more efficiently depending on living conditions and needs. Restorative corals, for example, contain other types and clades of Symbodinium as healthy corals. Different types of Corals contain different Symbodinium which then differ from each other according to the environment in which they grow.
For example: Quigley et al. (2014) considered the symbiosis between a Pacific coral and the Symbiodinium clade A lineage as a reduction in the health status of the coral. Clade A Symbiodinium is rare in coral hosts; however, this group has been described as fast-growing and opportunistic because it is found in corals that recover from bleaching events (Little et., 2004; Abrego et al. 2008). Quigley et al. (2014) demonstrated that Acropora cytherea from Hawaii that houses clade A, exhibits a suboptimal health condition and an increased incidence of diseases compared to corals sampled on the same reef containing Symbiodinium clade C. Stat et al. ( 2008) showed that genetic diversity actually existed within a single line of Symbiodinium, clade C. Such high levels of genetic divergence within the Symbiodinium genus supported that the group contains members with very diverse functions and physiologies, some of which will enable them to form symbiotic interactions with coral.(KValliappanEnCo2016)
The ability to identify and enumerate the abundance of dinoflagellates associated with corals is necessary for understanding holobiont physiology, stress sensitivity, and, ultimately, the resilience of corals to environmental changes.
Coral dinoflagellate symbiosis are defined as mutualistic. Examination of the zooxanthellae showed that both B. europaea and C. caespitosa contained Symbiodinium B2, but only B. europaea contained Symbiodinium clade A (Meron et al. 2012). No change in Symbiodinium diversity was observed after 7 months of exposure to a reduced pH. It has been suggested that the tolerance to various environmental stresses, such as light or temperature, is influenced by the Symbiodinium type (Baker 2003; Rodolfo-Metalpa et al. 2006; Jones et al. 2008). Indeed, clade A has been shown to resist short-term increases in temperature under experimental conditions to its host (Rodolfo-Metalpa et al., 2006).

 

[Hitman]

Any updates after you added the 500nm leds?

 

[k2-]

Bumping this old thread and see if there are any update on the 500nm LEDs