Clams and blue light?

[Slocke]

Very simply a blue thing reflects blue light. To photosynthesize an organism needs to absorb light not reflect. So is blue light useless for a blue clam? And so should a clam keeper be boosting the white (red, green, and other non blue) light spectrums?

@Miami Reef your the best person I know for clams

 

[KrisReef]

The zothanthelli inside the mantle absorb the spectrums they need to grow. The light reflected by the mantle is part mantle, part unused zoa light spectrum.

It is an interesting question, if the clam will grow faster with more white light? I think growers use natural sunlight but hopefully some folks will fill in the spectral gaps in our knowledge of clam PAR preferences?

 

[Miami Reef]

Since Tridacna tissues are refractive, probably best to use full spectrum lamps.
see here for details:

Coral Coloration, Part 9: Tridacna and Other Photosynthetic Clam Coloration, With Observations on Possible Functions

This month, we will continue our observations of marine invertebrate coloration with a slightly different subject - that of the impressive appearance of photosynthetic clams.

reefs.com

 

[Miami Reef]

From that article:

Strangely enough, and contrary to information in many hobbyist references, these clams do not contain colorful pigments. The ‘metallic’ iridescent colors we often see are caused by light reflected from tiny internal structures. Also involved are refraction, light interference and possibly diffraction.

 

[Slocke]

Thanks Miami! Very interesting. Seems like it is a defense for shallower clams from UV maybe too.
“The most popular theory seems to be one of photoprotection, where potentially harmful ultraviolet (UV) radiation and Photosynthetically Active Radiation (PAR, especially in the violet/blue/green portions of the spectrum) are simply reflected away from the animal and its symbiotic algae.
A simple test, though certainly not conclusive, would be to compare clam coloration to depth. Theoretically, clams reflecting blue and green light would be found in shallow depths.”
….
“However, with that said, generally we see blue and green coloration associated with clams often found in shallow depths, with yellow-browns at deeper depths.”

 

[Slocke]

The zothanthelli inside the mantle absorb the spectrums they need to grow. The light reflected by the mantle is part mantle, part unused zoa light spectrum.

It is an interesting question, if the clam will grow faster with more white light? I think growers use natural sunlight but hopefully some folks will fill in the spectral gaps in our knowledge of clam PAR preferences?

I’m just going by how green and red corals are by far the most common coral colors but then I guess purple is common in SPS…

Maybe those corals are in such high par areas of the ocean they need to reflect harmful UV levels??

 

[Stomatopods17]

Blue spectrum is typically what marine life gets most. This is due to blue reaching deeper in the water, while other spectrums are more easily 'filtered' by it. At the surface they get blasted with high intensities of blue while the other spectrums may be much lower. Most marine life as a result primarily grows off blue, and the other spectrums are weaker (like our typical light settings).

Macroaglea and friends can grow off rather low lumens of white spectrum, so they get by with what little the deeper 'plants' receive or grows closer to the surface.

A lot of stuff deeper in water that's more brown or plain is due to the color spectrum dropping significantly having less blue, while the ones further up have more color cause they're receiving more types of colors at higher intensity. As for why some are purple or some are rainbow, that's beyond me and we could probably ask that same question for every entity on land as well, they just have the colors either developed for being invisible to certain predators, attract certain prey, scare off certain predators, or got the "pretty" gene that passed on.

I personally have no knowledge of clams but this is the common theme when it comes to corals and I assume correlates. Too much of a spectrum they normally don't have in such large quantities could potentially bleach them rather than grow them faster perhaps.

 

[minus9]

Clams evolved to live in very shallow, clear waters, so trying to keep them in blue light seems pointless to me and will most likely make them "dull" looking. Also, the zoox that resides in a clam's mantle is kept in tube-like structures that work their way to the clam's stomach. Their mantles are designed in a completely different way than corals. Their ability to redirect, reflect and absorb light is pretty incredible.

 

[Doctorgori]

I’ve always chimed in on blue vs white light….
just remember “ white” is a composite color that contains blue

 

[Doctorgori]

Thanks Miami! Very interesting. Seems like it is a defense for shallower clams from UV maybe too.
“The most popular theory seems to be one of photoprotection, where potentially harmful ultraviolet (UV) radiation and Photosynthetically Active Radiation (PAR, especially in the violet/blue/green portions of the spectrum) are simply reflected away from the animal and its symbiotic algae.
A simple test, though certainly not conclusive, would be to compare clam coloration to depth. Theoretically, clams reflecting blue and green light would be found in shallow depths.”
….
“However, with that said, generally we see blue and green coloration associated with clams often found in shallow depths, with yellow-browns at deeper depths.”

Blue spectrum is typically what marine life gets most. This is due to blue reaching deeper in the water, while other spectrums are more easily 'filtered' by it. At the surface they get blasted with high intensities of blue while the other spectrums may be much lower. Most marine life as a result primarily grows off blue, and the other spectrums are weaker (like our typical light settings).

Macroaglea and friends can grow off rather low lumens of white spectrum, so they get by with what little the deeper 'plants' receive or grows closer to the surface.

A lot of stuff deeper in water that's more brown or plain is due to the color spectrum dropping significantly having less blue, while the ones further up have more color cause they're receiving more types of colors at higher intensity. As for why some are purple or some are rainbow, that's beyond me and we could probably ask that same question for every entity on land as well, they just have the colors either developed for being invisible to certain predators, attract certain prey, scare off certain predators, or got the "pretty" gene that passed on.

I personally have no knowledge of clams but this is the common theme when it comes to corals and I assume correlates. Too much of a spectrum they normally don't have in such large quantities could potentially bleach them rather than grow them faster perhaps.

Clams evolved to live in very shallow, clear waters, so trying to keep them in blue light seems pointless to me and will most likely make them "dull" looking. Also, the zoox that resides in a clam's mantle is kept in tube-like structures that work their way to the clam's stomach. Their mantles are designed in a completely different way than corals. Their ability to redirect, reflect and absorb light is pretty incredible.

a lil while back I posted something sorta tangential to this thread
My thread