Hybridization in Acropora

[Dana Williams]

Pedro- If I understood your description, I have seen this in some colonies
that I have been monitoring for the past 9 months. In these colonies I have
seen the translucent type skeleton between the 'acute' branches become
filled in and ultimately ends up looking like a typical A. palmata branch
tip. It seems as though some colonies elongate their branches by laying down
the framework then going back and filling it in, whereas others do it all in
one 'step'. My observations so far suggest to me that there are perhaps
different genotypes that vary in the way they build their skeleton rather
than hydrodynamic or light differences because not all individuals in an
area display this appearance...
That is my two cents worth (with the caveat of a relatively short, but
repeated observations)!
Dana Williams

Pedro Alcolado wrote:

> Dear listers,I was fascinated reading Vollmer and Palumbi´s recent paper
> on hybridization of Acropora palmata and cervicornis. It establishes
> clearly and convincingly the facts of that issue. But reading this paper I
> remembered an anecdote of mine. A few years ago I was visisting quite
> frequently (for different reasons, once staying 10 days there working on
> sponges) the nice Aquarium of Xcaret, Cancun. I was witness of something I
> think is amazing. In the big bowl representing the reef crest, there was a
> trasplanted Acropora palmata colony (the biggest one among others). There
> was full illumination and a wave simulator, with good water circulation
> there. I was able to observe how that colony was slowly being transformed
> in a prolifera bushy-palmate like fenotype. The ends of the palmate
> branches began to show short arising (in the same plane of the branch top)
> acute branches typical of prolifera, and the skeleton remaining between
> them becoming quite traslucent (looking like a duck foot illuminated at
> the opposite site). I wonder what was the final outcome of this gradual
> transformation. I observed that about 4 years (maybe less or more, I do
> not remember exactly) after I saw this colony for the first time. I would
> suggest that appart from well proved genetically derived prolifera like
> fenotypes, some kinds of changes in environmental variables (at least in
> acquarium conditions) would be able to lead also to the same bushy-palmate
> fenotype (maybe due to weaker hidrodynamic regime). Really interesting,
> no?Best wishes,Pedro Alcolado

--
Dana E. Williams, Ph.D.
Post Doctoral Associate
National Marine Fisheries Service
75 Virginia Beach Drive, Miami FL 33149
(305) 361-4569