Gerard J. Geertjes
g.j.geertjes at biol.rug.nl
Mon Oct 29 06:48:48 EST 2001
Hello Greg & coral list.
The little spheres that are released by Eusmilia fastigiata are actually
zygotes in very early stages of development (16-32 cells). At least part of
them (if not all) are released from the tips of the tentacles. Aspects of E.
fastigiata reproduction and development of the released spherical bodies are
de Graaf, M., G. J. Geertjes, and J. J. Videler, 1999: Observations on
spawning of scleractinian corals and other invertebrates on the reefs of
Bonaire (Netherlands Antilles, Caribbean). Bulletin of Marine Science
University of Groningen
Centre for Ecological and Evolutionary Studies
Department of Marine Biology
9750 AA HAREN
Tel: +31 (0) 50 363 2226
Fax: +31 (0) 50 363 2261
E-mail: g.j.geertjes at biol.rug.nl
----- Original Message -----
From: Boland, Gregory <Gregory.Boland at mms.gov>
To: <coral-list at coral.aoml.noaa.gov>
Sent: Friday, October 26, 2001 9:37 PM
Subject: Eusmilia spawning
> Coral List,
> This is in response to Dirk Peterson's request for information on Eusmilia
> fastigiata spawning. I thought it would be useful to post these images to
> the whole list even though David sounds like he is concentrating on the
> spawning behavior of this species for his graduate work. I indirectly
> acquired this image from a tourist/diver many years back when I was
> with the team that documented the first in situ mass spawning event in the
> Atlantic/Gulf /Caribbean in 1991 and the first Colpophyllia natans
> in 1994. This is an incredible image and I have always been puzzled about
> what is exactly going on. It was taken in French Cay of the Turks and
> Caicos Islands (not sure which island exactly) on August 28, 1994 at about
> PM. The full moon for August, 1994 was on the 21st at 23:48 so the image
> was taken 7 evenings after the full moon.
> The gametes appear to be individual eggs, much smaller than gamete bundles
> of Montastrea or Diploria species. I don't know if Eusmilia is dioecious.
> The strangest aspect is that the gametes or "eggs" are accumulated inside
> the expanded polyp tentacles. One would speculate that the eggs might be
> released through the end of the tentacles, but this seems very odd. They
> are getting out from somewhere as there are many gametes visible in the
> surrounding water. Could be the gametes in the tentacles are trapped and
> should have been retained in the gastrovascular cavity for release through
> the mouth as other taxa do.
> The close-ups are from the same image, only cropped and scanned at the
> highest resolution I could squeeze our of my Coolscan III.
> It is my understanding the photographers have no concerns about photo
> but here are their names anyway, as I have always been a stickler for
> credit , particularly for underwater images.
> Photos by: Anne Owen and David Wheeler, 1994
> Greg Boland
> Biological Oceanographer
> Minerals Management Service
> You can use the URL below to view the images:
> For directions on subscribing and unsubscribing to coral-list or the
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