Thoughts on Akoya culture

[jshepherd]

Zeide,

Any thoughts on the nucleus vapor encapsulation process being tested by Paul Cross? They are awaiting a patent, and I have spoken to him about using it. He will provide the materials free of charge (we are going to be using 1.9-2.1 BU), but they will probably not be available until late October or November, pushing back nucleation.

Also, current mantle tissue prep is more or less universal, I believe, with cutting off the marginal mantle and muscular. Then creating a 3mm strip to be cut into 2.5 rectangles. But, Cross has talked of developing a new tool to create perfect 2.5mm round pieces of grafting tissue. This way the sac does not develop from the corners first, and the pearls will have a better consistency in shape and quality.

Just wondering if you have any thoughts on either of these.

 

[Zeide Erskine]

Hi Jeremy,

The nucleus encapsulation will definitely result in more even nacre growth and thus rounder pearls. That will be particularly important if you intend to cultivate longer for thicker nacre. The shaping of the tissue is really the biggest factor in tissue-only nucleation.

For tissue-and-bead nucleation you would probably get the absolutely optimal results when chemically engineering a "perfect conchiolin," evenly coating the nuclei in it and then dip it in micro-chopped mantle tissue and let the pearl sac close in culture medium before implanting it in the host gonad. Now, that process is a touch on the high tech side, but since I know that you have seen hama age before, you will understand that having a 100% round and ros? white output with virtually no rejects is a rather good idea. You may get something up to 60% hanadama grade right out of the shell that way. However, the process would not come cheap and now that I published it on a public forum is no longer patentable.

Zeide

 

[jshepherd]

The encapsulation would not be done with the intent of quicker nacre deposition. The thought behind it is that 2nd and 3rd grade would be usable and equivalent to first, while costing 75% less, and utilizing the much more of the shell. Currently only first grade is considered usable in China and Japan, and even then a month of sorting is still necessary.

Regarding the cutting device used on the pallial, he mentioned that he has used it with good success in French Polynesia, with noticeable differences. But I have never seen anything like it at an Akoya farm. I imagine it would make a greater difference with thicker nacre, and I understand the science behind it, but I am not sure - being the first in something untested could be a bit risky.

There are a lot of things I want to implement, and a lot of things will be implemented. This first try is more of an experiment than anything else. But waiting nearly 2 years to really know, and being certain the next time many things will change...would love to see 60% Hanadama. Never mind that - would love to see 6% Hanadama. But I can only imagine what it would take to get my partner to agree to an attempt at "invitro" planting of a closed sac. He may consider a test, however. But that is a technology they do not have, and not one I would be able to bring to the table.

 

[Zeide Erskine]

Hi Jeremy,

It depends on the color, reflectivity, and stability of the coating material whether this is going to be viable option. If the coating is supersmooth and stable, nacre will not grow on it evenly. If it is too rough or soluble it will give you Kasumi-like surfaces and a tendency for the nacre to separate from the nucleus. The coating has to be stable enough to withstand the bleaching and dying process and reflective enough to hide the layering of the nucleus. So you can really only use it for long cultured pearls (minimum of two years, probably more). The size of the tissue graft is really more of a factor than the shape because larger grafts form pearl sacs faster and those will have more calcium carbonate-secreting cell islands. After all, you will need quite thick nacre if you intend to use encapsulated beads since you cannot use as much processing without compromising the coating and thus wind up with zebra pearls.

Zeide

 

[jshepherd]

That would be one of my major concerns. Using 3rd grade nucleus would be very risky, but if it works as purported, quite a strain would be lifted from the species, and nucleus cost would drop from $45,000 (per million) to around $12,000.

I had quite a long conversation with Mr. Cross about the method. And the color and reflectivity traits are their strongest with the vapor method.

http://www.islandpearls.net/newtech.htm

We may have to try a portion with one and a portion with the other in a sort of controlled experiment. But if it works perfectly, we would be 2 years behind the Japanese farmers who would do nearly anything to pull away from the brink of extinction where they are today.

 

[Caitlin]

Island Pearls is a most interesting site. Paul Cross is an American who is very cutting edge in pearl technology. Also very politically correct.

Also read the following page for a 1998 story re stealing mussels from the MI River Basin and selling them to the Japanese.
http://www.islandpearls.net/article3.htm

Also above article mentions the rarity of these shells and that was 8 years ago. The above article really ties in with a recent theft reported from the Muskogan river https://www.pearl-guide.com/forum/showthread.php?t=542