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Abstract MICROBIAL ECOLOGY OF CORALS: INVESTIGATING BACTERIAL COMMUNITIES IN EARLY LIFE STAGES OF CARIBBEAN CORALS. Koty Sharp Coral cover and diversity worldwide are heavily threatened by environmental
changes and outbreaks of coral bleaching and disease. Healthy scleractinian
corals have been shown to harbor diverse assemblages of microbes,
but neither the specificity of these associations nor the mechanisms
that maintain them across host generations is well-understood. In
order to implement effective management strategies and conservation
concerning unhealthy and diseased corals, it is critical to learn
more about the diversity and functions of bacterial assemblages
in healthy corals. To date, there are only a limited number of examples
in which the role of bacteria on coral health is well-understood.
Some corals, including the Caribbean corals Porites astreoides
and Favia fragum, brood larvae within adult colonies, releasing
fully developed swimming planulae into the water column. In this
study, bacteria were found in the planula larvae of both P.
astreoides and F. fragum. Molecular techniques were
used to identify microbes associated with larvae, and sequence-specific
oligonucleotide primers were designed to survey multiple samples
for the presence of particular bacterial species. Fluorescence in
situ hybridization (FISH) and microscopy were used to localize particular
species within the larvae and determine relative abundance of certain
groups of bacteria. Egg-sperm bundles released from Montastrea
and Acropora, which, in contrast, reproduce via mass-spawning,
did not appear to contain bacteria or archaea. These results reveal
new insight into mechanisms by which marine invertebrates maintain
complex microbial assemblages during embryogenesis and early development.
In addition, the localization of bacteria in the larvae present
the possibility for a bacterial role in larval settlement of some
coral species.
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