'Blue' coral -Reply

Yusef Fadlalla yfadlal at kfupm.edu.sa
Tue Jun 9 07:48:25 EDT 1998

> Dear fellow coral'lers,
> >> Patrick Mitchell-Jones <patmj at cdstecsv.demon.co.uk> wrote:
> >>
> >> Whilst diving in the Maldives (North Ari Atoll) recently, I
> >> commented on the large number of 'Blue' and Blue tipped' coral
> >> growths which have previously been white/cream. Some appeared to
> >> be turning pale blue from the tip downwards, others had patches
> >> of blue.
> > Craig Bingman <cbingman at netcom.com> replied:
> >
> > Host autofluorescent pigments (some of which are blue) are more
> > easily observed when the symbiotic dinoflagellate population of the
> > coral is reduced, as in "bleaching" from high temperature or high
> > irradiance.
> >
> > This is one possible explaination for the observation.  There may be
> > others.

> Jan Korrubel added:
> >I would be most interested to hear more about this.  While diving in
> >Sodwana Bay (northern east coast of South Africa) very recently (last
> >week), we too observed this "blue phenomenon".  As mentioned above,
> >the blue can be light in colour or very bright, affecting the entire
> >colony.
> >In addition to the blue, we also noticed numerous _Porites_ colonies
> >with a luminescent/flourescent pink border - can this be attributed
> to
> >the same phenomenon?

In the Gulf (Saudi Arabia) we at first (many years ago) thought that
a species of Porites (cf compressa) had no less than five different
morphs, including blue and pink.  We are now certain that these colors
appear under stressing conditions (extreme cold or warm waters).

Colonies of Porites in the Gulf normally appear brown/beige/drab yellow.

When they apparently lose their algal symbionts, these same colonies
would appear either bright off-white (light tissue pigmentation) or
bright off-white with the blue or pink hues that have been described by
other observers.

In the majority of occurrences, the corals suffer limited or no
and would eventually recover their typical brown colors.

Yusef Fadlallah
Research Institute
King Fahd University
Dhahran 31261
Saudi Arabia

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