Giant Clams Manipulate Light To Assist Their Symbiotic Partner (phys.org) 13
Special cells in giant clams shift the wavelength of light to protect them from UV radiation and increase the photosynthetic activity of their symbionts, shows research from King Abdullah University of Science and Technology -- originally intended as a photonics investigation. Phys.Org reports: Like corals, giant clams are important players in reef ecosystems and live in symbiosis with photosynthetic Symbiodiniaceae algae. The clams also have special cells, known as iridocytes, that can manipulate light via layers of nanoreflectors within each cell. Earlier work has shown that these iridocytes scatter and reflect light to increase the photosynthetic efficiency of the Symbiodiniaceae algae. Now, a team of researchers at the Red Sea Research Center and the Photonics Laboratory have discovered another way that iridocytes help the symbiont to photosynthesize. The researchers studied the morphology and optical characteristics of iridocytes in the giant clam Tridacna maxima and found that they absorb UV radiation and re-emit it as longer wavelength, photosynthetically useful light.
Ram Chandra Subedi, one of the study's authors, explains that the iridocytes contain alternating layers of high-refractive index guanine crystal and lower refractive index cytoplasm. Compressing and relaxing these layers enables the cell to tune its effect on light. As a result, "the guanine palettes not only reflect harmful UV radiation but also absorb it, and emit light at higher wavelengths which are safe and useful for photosynthesis," he explains. This increases the amount of photosynthetically active radiation available to the algal symbiont and also helps protect both the clams and algae from UV radiation. This photoprotective effect enables giant calms to live in very shallow tropical waters where there is enough light for photosynthesis, but also potentially harmful UV radiation levels. The report adds that this research may help explain the mantle colors of giant clams. "The idea is that the vibrant colors of giant clams are not due to optical differences in the tissue, but rather differences in the distribution or abundance of symbionts relative to iridocytes in each individual," reports Phys.Org.
The research has been published in the journal Frontiers in Marine Science.
Ram Chandra Subedi, one of the study's authors, explains that the iridocytes contain alternating layers of high-refractive index guanine crystal and lower refractive index cytoplasm. Compressing and relaxing these layers enables the cell to tune its effect on light. As a result, "the guanine palettes not only reflect harmful UV radiation but also absorb it, and emit light at higher wavelengths which are safe and useful for photosynthesis," he explains. This increases the amount of photosynthetically active radiation available to the algal symbiont and also helps protect both the clams and algae from UV radiation. This photoprotective effect enables giant calms to live in very shallow tropical waters where there is enough light for photosynthesis, but also potentially harmful UV radiation levels. The report adds that this research may help explain the mantle colors of giant clams. "The idea is that the vibrant colors of giant clams are not due to optical differences in the tissue, but rather differences in the distribution or abundance of symbionts relative to iridocytes in each individual," reports Phys.Org.
The research has been published in the journal Frontiers in Marine Science.
symbionts are people too (Score:2)
Ignorant question (Score:3)
Re: (Score:2)
I don't thing it makes all that much sense. Plants have their own use for UV light. So do many reflect it with their blossoms for insects to see. Then of course do plants get along with the natural day light quite well, they sure had enough time to evolve, and you shouldn't need any extra light. And in greenhouses where you do need extra light will it likely not be enough but you'll have to install additional lamps anyway.
Solar panels might have a use for it, but chances are the material used in converting
Re: (Score:2, Funny)
If we inject some of these into Joe Biden could that possibly let him communicate effectively? The guy is a cross between a walking gaffe machine and a corpse. But of course Orange Man worse. Somehow.
Or perhaps, as the Democratic Party sincerely wished, he'd just clam up. /s
Cause vs effect (Score:4, Insightful)
Both TFA and the /. summary seem to suggest this is the result of some deliberate action by the clam.
From TFA: "...Compressing and relaxing [specific cell] layers enables the cell to tune its effect on light. As a result, "the guanine palettes not only reflect harmful UV radiation but also absorb it, and emit light at higher wavelengths which are safe and useful for photosynthesis," he explains."
Wouldn't it be more plausible to suggest that the clam had this ability to mitigate UV to some degree, and the symbiotic algae growing on it specifically evolved to exploit it? Then certainly it's conceivable that if the algae is beneficial to the clam, those that could do it 'better' would outcompete their neighbors?
I for one (Score:2)
welcome our new Giant Light Manipulating Clam Overlords
When I think giant clams... (Score:1)
And when they grow a pearl (Score:2)
then it gets used as a disco ball and all the symbionts are having a good time. The End.