[Coral-List] Gorgonian Sea Fan Identification

[Catherine Drew Harvell]

Dear Joe:

There is a fair amount of controversy on this point, since they are both
phenotypically variable and extremely difficult to distinguish. G.
flabellum tends to predominate in very shallow water and G. ventalina
below approximately 2 meters, but this is dependent on the wave energy in
any location. But to be sure you have them sorted out in your habitats,
you will need to consult Bayer's taxonomic guide to Caribbean Gorgonians
and examine the sclerites under a microscope. The sclerite morphology does
differ and you can work back to confirming your field identifications once
you have checked the sclerites.

IN terms of Aspergillosis, we have not recently seen very many active
infections. In Puerto Rico, we are seeing more spotting caused in part by
labyrinthulid infections. Ideally, you will need both histological and
culturing to confirm if your fans have aspergillosis, since many different
biotic factors trigger purpling and lesions. If you do find an increase in
Aspergillosis in the Caymans, I would love to know about it!

Kind Regards, Drew


Drew Harvell
Associate Director for Environment
Atkinson Center for a Sustainable Future
216 Rice Hall
http:/Sustainable Future.Cornell.edu

Professor
Dept of Ecology and Evolutionary Biology
321 Corson Hall
Cornell University
ithaca, New York 14853
(607)-254-4274
cdh5 at cornell.edu
http://www.eeb.cornell.edu/harvell/harvell.html
http://www.theharvelllab.blogspot.com/










On 6/13/12 9:55 PM, "Joseph Marlow" <joemarlow_2000 at yahoo.co.uk> wrote:

>Dear Coral Listers
>
>I'm a MSc student studying the Aspergillosis disease in Gorgonian sea
>fans in the Cayman Islands. I'm having a lot of difficulty distinguishing
>between G. ventalina and G. flabellum, I know there is a difference in
>the branch structure but am unable to identify this difference
>underwater. I wander if anybody has any handy tips for aiding the
>identification of the two species?
>
>Thanks and regards
>
>Joe Marlow  
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