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Dark
purple tumors on a sea fan.
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Colonies
of sea fans often have numerous (2-50) spherical nodular growths
extending up the colonies main axial blades. These nodules are dark
purple and consist of hardened accretions of endoskeleton (gorgonin)
deposited around algae, fungi or other irritants. The increase in
nodules is often associated with continuing tissue death and erosion
of the skeleton.
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Neoplasms
are characterized by a proliferation of gastrovascular canals and
associated calicoblastic epidermis, with a degeneration of normal
polyp structure and loss of symbiotic algae. Often the center of
a tumor has a smooth appearance, while the tissue at the margin
has a bubbled appearance, due to rapid cell multiplication. As the
tumor enlarges, the epidermis loses cells that help remove sediment
from the coral surface. The tissue may become ulcerated and invaded
by filamentous algae.
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Neoplasia on elkhorn
coral, A. palmata. |
