Purple rings

[Cindy Hunter]

Dear Laurie,

>From your description, the lesions you've seen are most likely not caused
by the trematode cysts that Greta has worked on--those can be
distinguished as involving individual, swollen (and often pink) polyps.

Might they be the result of tissue loss from fish bites?  I have seen
lesions similar to those you decribe (ovoid, dime-to quarter size, with
algal filaments or incipient turf) on Porites colonies on many Pacific
reefs. Often the edges are pink to violet, a common attribute of stressed
(as from the trematode cysts), abraded, or rapidly growing coral tissue.

In Hawaii, such bite marks are made by large blennies (Exallias brevis),
puffers, and parrotfish. Why the scars are sometimes invaded by
cyanobacterial or algal turfs before they heal is an intriguing question,
but I haven't noted a correlation with proximity to any known
anthropogenic source of stress. That is, these kinds of lesions (and other
"diseases" of corals in the Pacific) are as common on remote reefs like
Ofu in American Samoa as on reefs near Waikiki.

On a related note, I have a suspicion that many coral neoplasms on Pacific
Porites stem from fish feeding scars--the process involved there is
another intriguing question!

I've posted Greta's email address with this message. I'd be happy to
continue a correspondence on your thoughts and observations on Porites.

Aloha,

Cindy Hunter
Curator
Waikiki Aquarium
2777 Kalakaua Avenue
Honolulu, HI 96815

On Fri, 7 May 1999, Laurie Jeanne Raymundo wrote:

> Hi, all:
> 
> I am searching for information on a disease referred to as Porites Purple
> Ring Disease, in the Indo-Pacific.  I have seen small massive Porites
> colonies often infected with ovoid lesions (2cm diameter), with dead tissue
> in the middle of the lesion colonized by algal tufts, and around the
> perimeter of the lesion is a very distinctive pink-purple ring.  So, two
> questions:  does anyone know if this is the trematode infection that Greta
> Aeby reported in 1992 (Greta: if you're out there, I'd love your email
> address so we could talk further!) and has anyone heard of any other
> publications on this?  It's not on the McCarty-Peters web page, and hasn't
> been mentioned much, but those of us in the Indo-Pacific have seen it
> around (it was also reported from the Vietname area, I believe).  I'd like
> to make sure that the symptoms I'm seeing are the ones others are using to
> refer to as Porites Purple Ring.
> 
> Thanks to all who answer!
> 
> Laurie Raymundo
> 
> 
>