fungal infection
of sea fan.
Photo by
J. W. Porter.
| Opening | Introduction | The Key | Specific Diseases | Reading | You Can Do |
Not much is known about diseases of sea fans. However, one disease that is known to affect sea fans is aspergillosis, a fungal infection.
Mass mortalities of sea fans have been reported throughout the Caribbean in recent years, but the cause has not been evident. Ivan Nagelkerken and colleagues reported an epizootic causing mortalities of sea fans beginning in 1995, in which the fungal agent was identified.
| Aspergillosis, fungal infection of sea fan. Photo by J. W. Porter. |
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| Appearance | Affected sea fans (Gorgonia ventalina and G. flabellum ) show one or more irregularly-shaped patches or extensive loss of the purple tissue, with fine white filamentous material and sediment on the black axial skeleton that supports the tissue. Often, tissue adjacent to the patch is colored more deeply purple. Disintegration of the axial skeleton also occurs, leaving behind holes or complete loss of the sea fan blade structure. Sea fan tissue can also exhibit small dark purple spots and protuberant masses of purple tissue. |
| Cause | Samples of diseased sea fans from the Bahamas, British Virgin Islands, Curacao, Saba, and Trinidad contained fungal hyphae that are most closely related to the terrestrial fungal genus Aspergillus. Some species of Aspergillus are known pathogens of humans and other animals. Transmission experiments conducted by Smith et al. (1996)confirmed the ability of this fungus to cause the disease in the sea fan. Additional studies are underway by several scientists to determine the distribution of the disease, the source of the fungus, why it is killing the sea fans, and what other factors might be contributing to their demise. |
| Distribution | Caribbean. |
| Impact | Extensive losses of sea fans have been experienced on reefs around the Caribbean. |
| Opening | Introduction | The Key | Specific Diseases | Reading | You Can Do |