Julian Spring's email

[Robert van Woesik]

The 'Phoenix' phenomenon continued:

Some observations from Helen Reef near Palau, in April 2000:
Colonies of P. cylindrica at 4-5 m were partially dead on the tips of
the branches but the base of the colonies had survived. Notably, many
partially dead P. cylindrica colonies were recovering by the following
process: the basal portions had extended toward the tips of the
branches. This does not happen with most Acropora colonies (excluding
Isoporas that have no axial corallites) because they do not appear to be
able to initially extend laterally, which is necessary in this recovery
process, before extending distally, to the tips of the colonies.
Therefore, once an Acropora colony (with axial corallites) is damaged at
the tips of its branches the rest of the colony will usually die; the
same effects are seen for Acanthaster planci predation.

(see MEPS 164: 213-220, 1998)
For massive Porites, regeneration commences by an initial 2-3 mm upward
growth of the healing edge followed by lateral encroachment of soft
tissue and skeleton toward the lesion's centre within the first month.
Lesion  scars are evident in core samples, there is usually a 1 mm gap
(see photos in above citation) and clearly the trabeculae and
synapticulae structures over the healed lesions are more porous than in
other parts of the colony. Indeed, their existence may help clarify the
extent of historical damage to Indo-Pacific Porites spp. through
sclerochronological investigations, and refine predictive models on the
occurrence of small lesions on Porites where some laudable
sclerochronological studies have already been carried out.

Rob van Woesik

*******************************************
Dr. Robert van Woesik
Associate Professor
Department of Marine Sciences
University of the Ryukyus
Nishihara, Okinawa 903-0123
JAPAN

E-mail: b984138 at sci.u-ryukyu.ac.jp
Website: http://www.cc.u-ryukyu.ac.jp/~b984138/

Ph: (81) 098 895 8564
Fax: (81) 098 895 8552

*******************************************
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://coral.aoml.noaa.gov/pipermail/coral-list-old/attachments/20000918/7e8d75b4/attachment.html