purple branching Porites

[Stephen C Jameson]

Dear E. McRae,


Thanks for your interesting question regarding the mysterious purple 
branching Porites.  

I'll put my response out to the list as this would make a very 
interesting topic for graduate work in coral taxonomy.

I ran across this specimen in only one location during my field work.  I 
took a dug-out canoe from Carrie Bow Cay and sailed seaward for what 
seemed like an eternity (I guess it was because I was bailing out the 
canoe with a coffee can most of the time).  It was out at Glovers Reef 
(Northwest Cay) in a very shallow water (about 15 cm) calm leeward 
environment where I found these specimens.  I also collected specimens 
that were pale yellow in the same area - with the same growth form.

At first I thought I had Porites branneri because of the purple color and 
flat shape but after looking at the corallite characters I noticed the 
columella tubercle which P. branneri does not have.  I didn't think they 
were P. furcata because in Belize they prefer a more high energy reef 
flat environment.

Back at the Smithsonian, I did a multivariate discriminate analysis on 10 
of these specimens and found that they fall closer to Porites porites 
when looking at corallite characters.

Here are the possibilities that cross my mind:

1.  These specimens could be juvenile P. porites as they have a flattened 
base with just small projecting fingers;

2.  They could be older P. porites with a unique growth form shaped by 
the very shallow and calm water environment.

3.  They could be a new species.  It would be interesting to do 
electrophoresis or other genetic techniques on them.


Questions for you:

1.  What type of environment did you find your specimens in?  

2.  I would be interested to know if anyone else out there has run across 
these specimens?

Thanks again for the question.  I look forward to hearing from you.



>Dear Stephen; 
>
>I read your comments in coral-list and was curious about the purple
>Porites (also in Belize). Usually this is a very small colony, ie often
>just little stubs projecting above the sand; but sometimes a small colony 
>is seen. The largest colonies I've ever observed are no more than 0.5m in 
>diameter; most are considerably smaller, unlike the pale green branching
>Porites. The Kaplan guide (1982) calls it P. furcata (a rare purple phase); 
>But then why are the green colonies so much bigger if it is the same sp? 
>
>E McRae
>The Siwa-ban Foundation
>Caye Caulker
>Belize, C.A.
>sbf at btl.net


Best regards,

Dr. Stephen C. Jameson, President
Coral Seas Inc. - Integrated Coastal Zone Management
4254 Hungry Run Road, The Plains, VA  20198-1715  USA
Office:  703-754-8690, Fax:  703-754-9139
Email:  sjameson at coralseas.com