Simplified
Key to Stony Coral Diseases and Coral Predation
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All
scleractinian (stony) corals except Acroporids (staghorn and elkhorn
coral)
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| 1. |
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to...
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A.
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Presence
of Recent Mortality |
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B.
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Very
little or no recent mortality, but colony may have old mortality;
tissue adjacent to exposed skeleton is discolored (lighter or darker
than normal); or tissue within colony area is lighter or darker |
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| 2. |
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A.
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Tissue
is missing but skeleton is intact |
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B.
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Tissue
may or may not be missing; colony has irregular knobs, projections,
or galls |
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C.
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Tissue
is missing and skeleton is damaged or abraded |
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| 3. |
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A.
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Tissue
is missing and there is the presence of a dark mat of filamentous
organisms at interface of live tissue and recently denuded skeleton |
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B.
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Tissue
is missing but there is an absence of any apparent mat or band of
microbial organisms |
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| 4. |
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A.
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Mat
is black to dark red/purple, may have white dusting |
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B.
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Mat
is light red, and loosely organised in a band with obvious filaments |
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| 5. |
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A.
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White
exposed skeleton forms a band that is advancing up the coral |
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B.
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White
exposed skeleton forms a series of blotches or irregular patches |
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| 6. |
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A.
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Tissue
loss is progressing in a uniform band across the colony; tissue adjacent
to exposed skeleton is sloughing off; recently exposed skeleton may
be 10-20 cm in diameter; tissue adjacent to exposed skeleton has normal
pigmentation or may be slightly bleached |
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B
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Tissue
loss is progressing in a uniform band, but the margin of live tissue
has a scalloped appearance, or it is lost in an irregular path; tissue
is not sloughing off the coral and is fully pigmented; snails may
be present |
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| 7. |
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A.
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Tissue
is discolored in splotches or patches; recent mortality (white skeleton)
is minimal or not apparent; corallite structures are normal or slightly
depressed |
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B.
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Tissue
is lost in a series of irregular patches; may be sloughing off the
colony; live tissue is mottled or pale in color |
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C.
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Tissue
may or may not be discolored; corallites are enlarged, are irregular
or are lost, but the skeleton has not been abraded |
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| 8. |
Colony
has little or no recent mortality and: |
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A.
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Affected
tissue is lighter than normal tissue; affected tissue consists of
a series of light yellow to lemon yellow discolored blotches or a
band that is 0.5-5 cm wide, within the colony surface or at the edge
of the colony; colony is a faviid coral, especially star coral (Montastraea
spp.) |
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B.
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Affected
tissue is lighter than normal tissue, may be pale or white; colony
may have no obvious recent or old mortality. All species; may affect
the entire colony, the base, or the upper surface only |
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C.
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Affected
tissue is darker than normal tissue, may be slightly depressed; typically
observed in blushing star coral (Stephanocoenia) , starlet
coral (Siderastrea) and star coral (M. annularis) ;
may have small areas of recently denuded skeleton or no obvious tissue
loss |
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| 9. |
Colony
may have little or no recent mortality and: |
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A.
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Corallite structure is visible, but corallites are enlarged and deformed;
affects all species |
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B.
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Corallite
structure is partially or fully lost; tissue is pale or white in colour;
affected area forms an enlarged gall or knob; |
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10.
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Live
tissue has been lost and corallites have been abraded or are missing
and |
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A.
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Large
patches of skeleton and tissue have been removed, often in a band
that extends over the upper surfaces of the coral, or affects only
the ridges of a brain coral |
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B.
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Individual
corallites are missing; affected areas may be colonised by turf algae
or appear as white spots |
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| 11. |
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A.
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Large
patches of tissue and skeleton have been removed in a band or line
that extends across the upper surface of the coral (M. annularis),
affects only the edges of plating coral (M. faveolata, C.
natans, Agaricia spp), branch tips (Eusmilia, Porites)
or knobs on M. faveolata colonies |
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B.
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Tissue
and skeleton have been removed from the ridges of a brain coral, but
remain in the depressions; tissue and skeletal loss progressively
radiates, with areas first affected ultimately dying and being colonised
by turf algae |
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| 12. |
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A.
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The
tissue and skeleton from individual or small groups of corallites
have been removed; affected area is generally not colonised by algae;
often occurs in pairs |
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B.
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Algae
has colonised affected areas and may be smothering the coral; the
coral is vigorously defended by an aggressive damselfish; affects
star corals, mustard hill corals and most other species |
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