Giant Clam Zooxanthellae

[chadcallan]

Just wondering what info is out there (or that you know) about Giant Clam zooxanthellae?

I'm particularly interested in what gives the "ultras" their vibrant coloration, compared to the more ordinary purples and browns.

I've had the chance to spawn and rear T. Maxima and have watched them grow. Though "ultra" donor clams were used to provide zooxanthellae, only ~ 5% of the resulting cultured clams could be considered "ultra".

Is this still a mystery?

Chad

 

[OrionN]

For someone who spawn and reared Giant Clams, you sure don't know much about clams. Zooxanthellae have nothing to do with the brilliant colors of the clams. It only gives the clam the brown color on the mantel. The pigments and bright color of the clams is genetically determined, not due to zooanthellae.

 

[chadcallan]

I never claimed to be knowledgeable in giant clam biology, just reported my observations...

However, my question should have been more clear. I was trying to ask 1) if the zooxanthellae in giant clams was the same sp. as in reef building corals and 2) if similar interactions between the zooxanthellae and the light absorbing pigments in the clam's mantle were responsible for the color patterns we observe?

You claim the color is genetic. References?

If color (lets ignore pattern for now) is inherited, than you would expect a predictable % using homozygous donors. It has been my observation, that this % is not predictable, and can vary widely from spawn to spawn using the same broodstock.

I suspect there is more to it than straight genes. Perhaps environment, time of year, light intensity etc...... thus my question about the zooxanthellae and possible interactions etc.

If it was as easy as genetics, there would be a HELL of a lot more "ultra" clams on the market today. Spawning and rearing giant clams is NOT HARD.

Still, and interesting topic and I'm eager to hear some more thoughts.