Abstract: Species-specific regeneration mechanisms of coral colonies after damages
and the presence of coral/algal competition in this process are poorly
understood. Here we report patterns of
regeneration in experimentally damaged scleractinian corals. Porites
lutea, P. cylindrica,
P. rus,
Montipora grisea, Pavona divaricataandAcroporasp.fragments of colonies were inflicted with hand saw injuries. The
fragments were maintained in outdoor aquaria for a period of 240 days under
light intensities varying from 20% to 90% of incident surface photosynthetic
active radiation Changes in weight of
the fragments, the regeneration rates of the injuries, abundance of algae and
animals settled onto injured areas were studied. The regeneration rate of the
injuries depended mainly on interspecific differences in corals, but not on
light intensity, number and composition of algae colonized the lesions. Two
mechanisms of coral recovery were found and studied. The first mechanism was
detected in Poritesspp. and in M. griseaand was characterized by live tissue spreading and covering algal and
animal settlers. In addition, the live tissue tightly adjoined to the
substratum, entombing the living and lifeless organisms settled onto the
substratum into newly formed skeleton or going round (encircling) the
impediments. The second mechanism was detected in the foliaceous coral P.
divaricataand in
branched coral Acroporasp.The mechanism was characterized by coral tissue (looked like
blade) consisting oftheliving tissue and thin layer of skeleton. The spreading “blade” did
not adjoin to the substratum and hanged over lesion at a distance of some
millimeters. It was found that the corals with this mechanism recovered faster
than Poritesspp.
Keywords and phrases: scleractinian corals, polyps’ regeneration, growth, morphology.
