[Coral-List] White-spined Diadema antillarum (Esther Peters)

Lessios, Harilaos LESSIOSH at si.edu
Tue May 20 19:07:56 EDT 2008

I have been following the white Diadema e-mails but have kept silent,
because the observations mentioned are nothing new, and because neither
I, nor anyone else knows the answers.  Since Alina mentioned my name,
here is my two cents worth.  

Alina is right there have been white Diadema even before the mass
mortality, and they were not all that uncommon.  One could find them in
caves during the day, and they were easy to find in the open during the
night.  White and black Diadema show no differences in either isozymes
or mitochondrial DNA, but this does not mean all that much.  The
difference could still be genetic, but we would have to know what locus
controls color to find out if there is allelic variation in it.  My
feeling is that if the differences are genetic, it is not a simple
genetic system (like albinism), but a complex interaction between
genetics and environment.  I have no evidence for this, but as Gordon
Hendler mentioned, there is both an ontogenetic progression from banded
to black spines (which can be retarded by keeping the animals in the
dark) and a tendency for all Diadema to be a lot paler at night, which
means that color to some extent is induced by light.

Has the frequency of white Diadema increased after the mass mortality?
I wish I had the pre-mortality data to test for it, because it would
have been a neat story of the strange ways natural selection works.  My
impression is that yes, white (or partly white) Diadema are now more
frequent (not necessarily more abundant).  The story I have concocted
about this comes from observations of what was happening when mass
mortality hit a reef.  For a few days, there would be Diadema, still
alive, tumbling in the waves, because their tube feet seemed to be
unable to cling to the substrate.  Following each tumbling Diadema was a
cloud of fish that would normally never eat adult Diadema, pomacentrids,
acanthurids, labrids.  Eventually something would crack the sea urchin,
and everyone would have a feast.  For a week or two after that, there
were no Diadema to be seen on a reef, but then some survivors would
appear (presumably from hiding places) with their spines broken half-way
and beginning to regenerate.  Now, if part of the mortality was due to
predation by fish following these wave-swept Diadema, then Diadema in
caves had an advantage, and since most white Diadema were in caves
during the day (when herbivorous fish are active), white Diadema would
survive slightly better than black ones.  

This is a just-so story.  It could well be that white Diadema is not
more frequent, it is just that we all look more carefully at each
Diadema we encounter these days.  We also do not know if the white
Diadema we see today had white Diadema parents.  And not all of mass
mortality was caused by debilitation followed by predation.  Diadema in
aquaria with sea-water intakes died at the same time that Diadema on the
reefs were dying.

If anyone wants to know more about photosensitivity in Diadema, they
should look at Millott's studies.  A good summary is in: Millott, N.
1975 The photosensitivity of echinoids. Advances in Marine Biology
13:1-52, but Millott did not address the question of white Diadema.  

H.A. Lessios
Smithsonian Tropical Research Institute
Balboa, Panama
Telephone: +507/212-8708
Fax: +507-212-8791
Telephone from the USA (domestic call): (703)-487-3770 x 8708
Mail address:
>From the USA:
Unit 948
APO AA 34002-9948
>From elsewhere:
Box 0843-03092
Balboa, Panama

-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov
[mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Szmant,
Sent: Monday, May 19, 2008 6:12 PM
To: Rex Chip Baumberger; coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] White-spined Diadema antillarum (Esther

Hi All:

I responded privately to the first white Diadema email, and thought
maybe Haris Lessios might chime in to the general discussion.  Since he
hasn't here it goes.

White spined Diadema have been around as long as I can recall (1960s) in
small numbers at least in the Puerto Rican populations.  After the
die-off they have become a much larger proportion of the population both
in PR and FL and elsewhere.  I asked Haris at least a decade ago whether
he had any indication about a genetic difference between the white and
black individuals, and I recall he hadn't found any.  But he also
recognized the shift in abundance of the two color morphs.

So, it appears that for some reason more of the white spined variety
survived the epidemic and contributed more offspring to the recovering
population.  They now occur together in varying proportions.  Juveniles
come in both all black and mottled colors, so it's not just an age
issue.  One possibility is that when they were sick, the black ones were
more prone to predation than the lighter colored ones.  Another would be
that there is some disease resistance genetically-linked to the color

Best wishes,

Alina Szmant

Dr. Alina M. Szmant
Coral Reef Research Group
UNCW-Center for Marine Science 
5600 Marvin K. Moss Ln
Wilmington NC 28409
Tel: (910)962-2362 & Fax:  (910)962-2410
Cell:  (910)200-3913
email:  szmanta at uncw.edu
Web Page:  http://people.uncw.edu/szmanta

-----Original Message-----
From: coral-list-bounces at coral.aoml.noaa.gov
[mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Rex Chip
Sent: Monday, May 19, 2008 1:50 PM
To: coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] White-spined Diadema antillarum (Esther

I recall seeing the occasional white-spined D. antillarum during the
past 4 years of reef monitoring off of south Florida. With that in mind
from recent posts here, I was diving off of Jupiter, Fl 5-15-08 at
65-70' on Jupiter Ledge, and I saw a white spined Diadema.  However, as
I got closer I noticed it was about 60% white spined and the rest normal
black spines.  I wonder if anyone has noticed this in with the
white-spined variety.  I have the GPS for it if anyone is interested,
the site is locally known as "Scarface".

Rex "Chip" Baumberger
Biological Scientist, FAU
Marine Nutrient Dynamics Dept.
Marine Science Division
Harbor Branch Oceanographic Inst.
5600 US1 North
Fort Pierce, FL 34946
772-465-2400 x398

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Subject: Coral-List Digest, Vol 59, Issue 18

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Today's Topics:

   1. Re: White-spined Diadema antillarum (Esther Peters)
   2. Reef Restoration (Lee Goldman)
   3. Re: Coral Reef Restoration (David Fisk)
   4. photoshop trick for sat imagery (Dean Jacobson)
   5. Re: Coral restoration (Medio, David)


Message: 1
Date: Sun, 18 May 2008 12:28:58 -0400
From: Esther Peters <esther.peters at verizon.net>
Subject: Re: [Coral-List] White-spined Diadema antillarum
To: Gordon Hendler <hendler at nhm.org>
Cc: coral-list at coral.aoml.noaa.gov
Message-ID: <4830594A.4010304 at verizon.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

I recall seeing large white-spined /Diadema antillarum/ in shallow water

at The Indians, rock outcroppings in the British Virgin Islands.  I was 
pregnant then, so could only snorkel, in 1988.  I remember thinking they

must not have been affected by the mass motality because they were so 
large.  They might have been able to stay in the shade of the

If one does a Google Scholar search on these key words "sea urchin 
melanin epidermis" one finds all kinds of interesting papers on and 
references to melanin production in the epidermis and effects of light 
and diet on pigmentation in these animals.  But more studies are needed!

Esther Peters, Ph.D.
George Mason University

Gordon Hendler wrote:
> According to Moore (1966:81) large Diadema antillarum with some or 
> many
> white or gray spines "...are found in darker and more turbid
conditions and 
> frequently in caves. In my experience, they seem to be more common in
> water around Caribbean reefs than at shallow depths. The spines of 
> juveniles are always banded with black and white. Individuals change
> in response to the intensity of illumination. Animals that are black
> the day pale at night.
> Hendler et al. 1995. Sea Stars, Sea Urchins, and Allies. Echinoderms
> Florida and the Caribbean. Smithsonian Institution Press. 390 pp.
> Moore, H.B. Ecology of echinoids. In: Physiology of Echinodermata, ed.
> Boolootian, 73-85. John-Wiley Interscience. N.Y.
> ********************************************
> Gordon Hendler, Ph.D.
> Curator of Echinoderms
> Natural History Museum of Los Angeles County
> 900 Exposition Boulevard
> Los Angeles, California 90007 U.S.A.
> Voice:  213 763 3526
> Fax:    213 746 2999
> ********************************************
> _______________________________________________
> Coral-List mailing list
> Coral-List at coral.aoml.noaa.gov 
> http://coral.aoml.noaa.gov/mailman/listinfo/coral-list


Message: 2
Date: Sun, 18 May 2008 10:43:14 -0700 (PDT)
From: Lee Goldman <coralfarmguam at yahoo.com>
Subject: [Coral-List] Reef Restoration
To: coral-list at coral.aoml.noaa.gov
Message-ID: <86461.29273.qm at web33206.mail.mud.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1

Hi List,
  The discussion on reef restoration is another example of a great topic
of interest for this list. My concern, however, is that it is reaching
an audience that is not necessarily the right audience. Todd, your
website (and your CNN interview) is filled with success stories in which
you talk about positive reef restoration. In your postings here, you
seem to understand that reefs cannot be restored to their original
glory. I agree that something must be done, even if we can't make them
what they were. BUT to the developers and polluters who ultimately cause
need for this work, the message may be that we are successful in
restoring reefs. Thus mitigating 'restoration' in exchange for
development appears to be a commonplace and accepted. So the dilema, to
me, is that as we get better  (or think we get better) at 'restoration'
developers use that as a means to mitigate potential damage...and all
along we agree, at least here in this like-minded and for lack of a
better term,  'in-crowd' list-serve, that it really isn't as successful
as we promote it to be to the general public (the audience that really
needs to be a part of this discussion). If this is the theme of Don's
postings, then I have to agree with him as well. Solutions to this
issue? Not that I can find. We can't do nothing yet anything that is
done is seen as a mitigating factor which falls well short of the
ultimate goal. 
  Lee Goldman
  Coral Farm Guam
  PO Box 6682
  Tamuning, Guam 96931
  Coralfarmguam at yahoo.com



Message: 3
Date: Sun, 18 May 2008 23:09:12 +0200
From: "David Fisk" <davefisk at gmail.com>
Subject: Re: [Coral-List] Coral Reef Restoration
To: coral-list at coral.aoml.noaa.gov
Cc: MedioD at halcrow.com
	<1dd51780805181409p2a8c963fx65cd87f283c93351 at mail.gmail.com>
Content-Type: text/plain; charset=WINDOWS-1252

The pertinent point I think from David Medio's comments is that it is
wrong to think that reef restoration can be used as an excuse to allow
some developments to proceed - at all, or in a certain proposed manner.
The argument that doing something (restoration) is better than doing
nothing, usually does not stack up when it is used as an argument to
accept a proposed development strategy. With the required sensitivity
and developmental controls, some developments may result in minimal
impacts, but the cost will usually be too prohibitive to be really
effective for most developments.

The true 'point of practicality' here is that restoration should not be
be used as that offset, nor should any 'smart' engineering per se, as
it's too easy to let serious impacts to go ahead when the current
knowledge base clearly shows such 'offsets' will not deliver what it is
promised. In previous posts I have said sufficient re the use of the
same technologies to reverse larger scale disturbances including
predicted climate change effects, but I still hear of proposals claiming
to do just that. For example, a publicly available UN document dated
April 2008 demonstrates how serious this situation has progressed, and
that I am not making idle arguments. Here is a recent UN link to a
UNDESA document called "Partnerships for Sustainable Develoment" which
may very well lead to substantial funding for certain restoration

In this web page the following statement is included (and note some of
the extreme statements) : "SIDS (Small Island Developing States)
fisheries, tourism industries, and protection from rising sea levels,
increased tropical storm frequency and intensity are heavily dependent
on healthy coral reefs?and these are the most climatically threatened of
all ecosystems, due to global warming. SIDS have already lost most of
their corals, and the rest are imminently endangered by rising global
temperatures, and most daunting of all, low-lying island nations are
threatened with extinction by submergence from global sea level rise."

Further on under the heading: Additional Relevant Information - New
RESTORATION "New technology increases the growth rates of corals several
times faster than normal, greatly increases survival of corals under
conditions of extreme high temperature stress, and greatly increases the
buildup of fish and shellfish populations. This allows reefs to be kept
alive where they would die, and new reefs and fisheries habitat to be
grown in a few years in places where they cannot recover naturally.
Because reef fisheries are collapsing due to habitat destruction,
control of fishing activities cannot restore fisheries without
large-scale habitat restoration. This restoration process is powered
using tidal, solar, and wind energy. "

As this information is in the public domain it is imperative that the
coral reef community is adequately informed of this as a means of
placing this discussion in a contemporary framework. Again, I apologize
if any individual is compromised by pointing out this trend - I am just
the messenger, and am not targeting anyone in particular. But I think it
is time that the wider coral reef community step up and insist on proper
scientific review and do not let commercial interests within the
scientific community drive this assessment of the allocation of critical
development funding for SIDS in particular.

David Fisk


Message: 4
Date: Mon, 19 May 2008 00:27:51 -0700 (PDT)
From: Dean Jacobson <atolldino at yahoo.com>
Subject: [Coral-List] photoshop trick for sat imagery
To: coral-list at coral.aoml.noaa.gov
Cc: Don Hess <cmihess at gmail.com>
Message-ID: <287849.35766.qm at web31803.mail.mud.yahoo.com>
Content-Type: text/plain; charset=us-ascii

Hi listers:

Today I "discovered" a useful way to filter satellite images using
Photoshop to reveals relatively deep reefs (below 15 meters).  (I am
fortunate to have access to 0.6 m Majuro atoll data for ArcMap). I am
using Photoshop 6.

Under "images", choose selective color, choose blue, then minimize the
black slider.  Then choose black, and maximize black slider.  Another
iteration may be needed.  Then, increase contrast and brightness.  To
avoid blowing out the shallows and land, first save an extra image
layer, make your adjustments, and then selectively erase the upper
adjustment layer so the original pixels show through.

The results were pretty remarkable; it was like having "X-ray vision"...
well-defined deep reefs magically appeared out of the monotonous dark
blue lagoon water.  This will work only if the stat image was taken an a
calm day; a wave chop seems to obscure the deep features.

I discovered this just in time for my coral monitoring season! I can
send some example jpgs upon request.

Dean Jacobson, PhD
College of the Marshall Islands



Message: 5
Date: Mon, 19 May 2008 09:17:42 +0100
From: "Medio, David" <MedioD at halcrow.com>
Subject: Re: [Coral-List] Coral restoration
To: "Douglas Fenner" <dfenner at blueskynet.as>
Cc: coral-list at coral.aoml.noaa.gov
<A87990669172924FADCAABF1721CB6EC0878E991 at LOND-MX-01.halcrow.com>
Content-Type: text/plain;	charset="us-ascii"


apologies! It is indeed the Arabian Gulf (Persian to some) I am
referring to!


Dr David Medio
Principal Environmental Scientist
Halcrow Group Ltd, Arndale Centre, Otley Rd, Headingley, Leeds, LS6 2UL,
tel: switchboard +44 (0)113 2208220, direct line: +44 (0)113 220 8253,
mobile: +44 (0)773 919 0968
fax: +44 (0)113 274 2924   email: mediod at halcrow.com

Halcrow   Sustaining and improving the quality of people's lives 
____ __
P Please do not print this e-mail and attachments unless absolutely

-----Original Message-----
From: Douglas Fenner [mailto:dfenner at blueskynet.as] 
Sent: 18 May 2008 00:18
To: Medio, David
Subject: Re: [Coral-List] Coral restoration

    Are you speaking of the Arbian/Persian Gulf?  I know its common to
refer to it as the Gulf in that area.  The coral-list has many readers
that are closer to the Gulf of Mexico, some near the Gulf of California,
and so on. 
Might be good to specify so no one is left wondering.  Thanks!  -Doug

----- Original Message -----
From: "Medio, David" <MedioD at halcrow.com>
To: <coral-list at coral.aoml.noaa.gov>
Sent: Friday, May 16, 2008 2:13 AM
Subject: [Coral-List] Coral restoration

>I am involved in a wide range of medium to very large coastal
>some of which a priori are known to damage long established reefs in
>Gulf. Whereas some of the recent artificial reef applications may well
>had positive results, I am as rule very sceptical on the use of and
>proliferaion as well as the political clout afforded artificial reef 
> Firstly, can we really recreate a reef (as opposed to relocating
> bits of a reef) in its complexity, function and extent?
> Secondly, using man made reefs, if pushed to the limit, as is the case
> many coastal and offshore developments in the Gulf, will amount
> to giving a green light to using such as a tool to offset large levels
> multi-layered damage to the marine environment, i.e. more than just
> coral habitats.
> Reefs in the Gulf are increasingly being described as far more
> and pristine and species rich than previuosly thought whilst at the
> coming under the greatest level of pressure ever experienced in the
> region.
> The answer for their conservation is cleverly designed engineering,
> and well implemented mitigation measures and environmental management
> plans, improved environmental educational and awareness and improved 
> regulatory frameworks.
> Dr David Medio
> Principal Environmental Scientist
> Halcrow Group Ltd, Arndale Centre, Otley Rd, Headingley, Leeds, LS6
> UK
> tel: switchboard +44 (0)113 2208220, direct line: +44 (0)113 220 8253,

> mobile: +44 (0)773 919 0968
> fax: +44 (0)113 274 2924   email: mediod at halcrow.com 
> www.halcrow.com
> Halcrow   Sustaining and improving the quality of people's lives
> __

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