FW: Dust and Disease on the Great Barrier reef

Thu Oct 31 09:16:19 EST 2002

Hi Alina (and others),

John Walch and I discovered a white nudibranch in Malaysia that also =
eats coral and using its gills to look like bleached coral polyps.  So =
check to make sure they are flatworms because these looked like =
flatworms when their gills were not extended.  They were tiny, but you =
could barely see them with the naked eye when they were forced out of =
the corals on the walls of the research aquariums we were working in.  I
have photos if anyone is interested.


Todd R. Barber
Chairman, Reef Ball Foundation
CEO, Reef Ball Development Group, Ltd.
6916 22nd Street West
Bradenton, FL 34207
941-752-0169 (Office)
941-752-0338 (Direct Line)
941-752-1033 Fax
941-720-7549 Cell
reefball at reefball.com

  ----- Original Message -----=20
  From: Alina M. Szmant=20
  To: Julian Sprung ; coral-list at aoml.noaa.gov=20
  Sent: Wednesday, October 30, 2002 11:29 AM
  Subject: Re: FW: Dust and Disease on the Great Barrier reef

  Hi Julian and others:

  We have come across a small flatworm in our aquaria that we suspect of
having eaten many of our juvenile corals.  They are only a mm or so in =
length and would not be noticeable to the un-aided eye of a diver.  We =
found them with high quality dissecting scopes.  They are full of =
zooxanthellae, and we found them crawling over our settlement plates =
with empty coral spat calices.  We've also seem nematodes feeding on =
coral tissues.  There are a lot of microscopic things out there killing
corals, it appears!   If any of you know what some of these tiny =
critters are, I'd appreciate help in IDing them.  I do have some =

  Alina Szmant

  At 08:38 AM 10/30/02 -0500, Julian Sprung wrote:

    Thanks for the article and links Gene. For what its worth, white=20
    syndrome-like outbreaks in Acropora in aquariums are often =
associated with
    pathogenic bacteria, and their occurrence and rate of damage is =
affected by
    temperature (high temps promote them).

    Slow-progressing bottom-up tissue loss is sometimes not caused by =
    but by predators instead. Reasearchers who study Caribbean Acropora
    familiar with the coral eating snails Coralliophila, whose affect on
    corals is often mistaken by casual observers for disease. In =
aquariums with
    Indo-Pacific Acropora there are occasionally similar snails such as
    Drupella, which fortunately don't reproduce and can be removed =
    easily. There are also nudibranchs such as Cuthona that leave dead =
    patches on coral, but these affect mainly Montipora and Porites.

    There is one predator of Indo-Pacific corals in aquariums (and =
presumably in
    the wild too) that often goes unnoticed, though its affect can be =
    The beast is Scutus cf. unguis, a black limpet that I'm sure occurs
on the
    Great Barrier Reef. These limpets are active at night only and do =
not stay
    near the coral during the day, so researchers diving during the day
    ever associate it with the dying coral. In aquariums Scutus has the
    unfortunate habit of reproducing prolifically, so its effect can =
    and result in the loss of all small polyped corals.

    I mention this here because the comment in the article, "it takes =
months to
    kill a large colony" sounds like it may be a predator. It may also =
be a
    disease, but the researchers involved should check the corals at =
night just
    to rule out Scutus.


    Julian Sprung
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