[Coral-List] Age of clones?

[Mark Heckman]

Thinking in practical terms here - as an educator that has to translate 
this to the public:

It seems to me that the "individual" in this case is any fragment or 
propagule that is physically separate from other propagules of the same 
clonal unit. Once we get into defining an individual coral by genetic 
components over time, it gets quite interesting - and complicated. Although 
a somewhat more absolute point is planula settlement - as noted, corals are 
annoyingly plastic.

Therefore I suggest that the "apparent age" of the individual begins with 
separation from the parent colony, even if the unit is a clone rather than 
a sexual propagule. Then, depending on the level of information desired, 
reference to the parental unit should be made. This would be similar to 
plant cuttings.

Reference to the parental unit can be vital. As Charles has noted to me in 
the past, as more and more corals are being propagated in captivity, and 
sold/ traded/ and exchanged -  questions as to ancestry and history can be 
very important.

Say that an Aquarium desires to create a new coral reef exhibit - goes to a 
wholesaler and wants to buy a number of corals, but also wants to know the 
heritage of the specimens. If all the wholesaler can tell them is that they 
are fragments that came from another wholesaler that got them from 
somewhere in the Pacific - they are of little research value. And obtaining 
import or export permits for them can be an issue.

Perhaps a labeling system should be encouraged. To include:

Date original fragment was collected. Collectors name. Location (as exactly 
as possible). Approximate size and health of parent colony. Image of parent 
colony (at times, we may want to find or relocate the parent - possibly 
even replace it if it was destroyed). An ID number for the fragment. 
Generation since original fragmentation/collection. I.e. if this was a 5th 
generation fragment - it might be A.s.101-5   or  A.s.101-5x(~). A simple 
numbering system might work here. Of course, maybe this is already done and 
I just am not aware of it.

Just my two cents,

Mark Heckman
Education Director
Waikiki Aquarium


At 08:43 AM 1/19/2006, Andrew Baker wrote:
>Dear Charles and Alina
>
>I would just add that somatic mutations will accumulate over the lifespan
>(whatever that might be) of a clone, changing the "genotype" in a slow (but
>possibly significant) fashion over time. In fact, large, old colonies might
>represent mosaics of multiple genotypes (there are a couple of papers by
>Fautin and Buddemeier et al. in the Proceedings of the 6th International
>Conference on Coelenterate Biology (published 1997) that discuss some of the
>implications of this at length, but I can't remember offhand if they
>discussed "lifespans" or not).
>
>I think it's interesting to think of coral colonies in this way (as
>"evolving clones"), but it surely complicates the notion of "lifespan". I
>think it's probably another example of how standard "animal" models don't
>apply to corals in straightforward ways.
>
>I'm sure there are some valuable lessons from the plant world that can be
>applied to this conundrum, but I don't know what they are! Anyone out there
>who can shed some light?
>
>Andrew
>
>___________________
>Andrew C. Baker, Ph.D.
>Assistant Professor
>Division of Marine Biology and Fisheries
>Rosenstiel School of Marine and Atmospheric Science
>University of Miami
>4600 Rickenbacker Cswy.
>Miami, FL 33149, USA
>Voice: +1 (305) 421-4642
>Fax: +1 (305) 421-4600
>
>-----Original Message-----
>From: coral-list-bounces at coral.aoml.noaa.gov
>[mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Szmant, Alina
>Sent: Thursday, January 19, 2006 6:23 AM
>To: Charles Delbeek; coral-list at coral.aoml.noaa.gov
>Subject: RE: [Coral-List] Age of clones?
>
>Hi Charles:
>
>Your question revolves around the issue of whether you are specifying an age
>of an isolate or the age of the actual genotype.
>
>With single celled algae the age of the clone is defined from when that
>single cell was isolated from it's neighbors and cleaned up.  The particular
>cell would be only a few days old at most at time of isolation, but the age
>of the genotype would be older.  Not sure if anyone has tried to age a
>genotype in such cells.  When did the first cell with that particular set of
>genetic characteristics come about from sexual reproduction?
>
>When one "clones" a coral, you are taking a piece of an animal that could be
>tens to thousands of years old.  Every coral colony starts from a sexual
>planula, so the chronological age of the coral colony and every fragment
>derived from it would be the settlement date of that planula.  Unless you
>find a good way to age the donor colony, then all you can specify is how
>long that genotype has been in culture (you can call that the age of the
>clonal isolate, but recognize that is not the same thing as the age of that
>genotype).
>
>Hope I didn't confuse you.
>
>Alina
>
>________________________________
>
>From: coral-list-bounces at coral.aoml.noaa.gov on behalf of Charles Delbeek
>Sent: Wed 1/18/2006 9:49 PM
>To: coral-list at coral.aoml.noaa.gov
>Subject: [Coral-List] Age of clones?
>
>
>We are getting ready to send out coral fragments and excess Entacmaea
>quadricolor anemones and I have a question. When one talks about the age of
>animals, how do you treat clones? For example, all the anemones we have
>originated via fission from a handful of animals collected from Palau in
>1980. So, are these anemones 26 years old ... or do you take their age from
>when they split? The same question applies to corals, we have specimens
>that we have been fragmenting for years, some of which were collected in
>1978 ... so are the fragments that old? Obviously for corals, new polyps
>are being produced and old ones die off, so these would not be almost 30
>years old ... but genetically they are the same as the original polyps ..
>or are they? With anemones, it would be different I think since the
>original tissue is still there.
>
>Dazed and confused in Hawaii....
>
>Aloha!
>
>
>J. Charles Delbeek M.Sc.
>Aquarium Biologist III
>Waikiki Aquarium
>2777 Kalakaua Ave.
>Honolulu, HI, USA 96815
>www.waquarium.org
>
>808-923-9741
>808-923-1771 FAX
>
>
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