Hi all. My yellow polyps have alway been a bright yellow since I've had them. They also never grew long tenticles nor propagated. Only recently I removed all mechanical filter media from the Whisper 60 hob; also increased feeding of flake food. Now the polyps are growing and they have longer tenticles that are browner.
I stumbled onto this site from looking for podcasts and the first one I listened to was episode 41 - xooxanthellae. I believe my polyps have "browned up" or whatever you call it.
What about ricordea and other shrooms that are neon green or blue and purple? Do they have golden brown xoox. too? Or are they asymbiotic?
mushroom coral are symbiotic, they do have zooxanthellae.
however many corals will come in many different colors.
those yellow polyps might have been unhealthy, and your adjustment brought them back to healthy state and color. brown is a normal color for Zoanthids. as for the mushrooms/ricordeas they typically are very colorful, and in in unhealthy state the color will fade to white.
see how it works..
healthy coral will have color, that color could be brown, purple, green, or blue.
as the health declines, the color "fades" and it turns lighter.
these are extremely general statements, there are many variable in determining the corals health, but hopefully this might give you an idea of whats going on. while i cant say for sure that they are improving, if you have pictures of before and after, that might help us.
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I was also wondering about collection of all the zoox. samples. "We sampled 95% of all the symbiotic organisms on the reef". If corals are slow-growing, is the collection process detrimental? Does anyone keep track of how many different scientific organizations are sampling the same reefs? I know the research is very important, but is anyone tracking the frequency of visitors and their activities at these dive sites? (sorry, I know there's specific podcast forums/threads this should be in)
When Dan said he sampled 95% of the organisms on a reef he meant 95% of the representative species on that reef. He didnt go around and literally sample 95% of all the colonies. All coral species are much faster growing than we give them credit for and I assure you that the collection impact is minimal. In most cases, scientific research requires a plethora of permits and the impact of a study is often matched in size with a reef that can support it. To put it in perspective though, it takes less mass than an eraser tip from a single coral to do a a multitude of molecular analyses. A friend of mine actually uses a syringe to suck up 1 or 2 individual polyps for zoox. typing. Corals can recover from this kind of sampling within a matter of days.
As far as your yellow polyps are concerned, it is very likely that the correlation between the increased nutrient input of your tank and the browning of you polyps is causal relatioship as well.
I have some yellow polyps in my tank. I moved them about a month ago and half the group turned brown. I changed the light that they recieved. The half that was in the shade of some coral were the ones that turned brown. I turned the rock around and the brown ones turned yellow, and the yellow one's turned brown. Just my observation
Victoria
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