Typescript of note on my 1995-1996 research.

I found the following on my hard drive as a scanned *.pnm file. Here it is, together with notes. I will edit it. I need to track this down, as it contains statements of mine that clarify issues that have become fogged over the years.

[Converted from a pnm file by tesseract, 15 March 2008, AED]
[Converted to tiff file: Millepora2.pnm -> Millepora2.tiff]
[This file was found on my system and run through tesseract on 15
March 2008. It is uncertain when the scan was made. I do not
recall where the original typescript might be located.]
[I have preserved the original typed text. Penned in corrections are
not here preserved, but it is planned to incorporate those
changes later on.]

Preliminary Results of a Study of Millepora sp. and its Zooxanthellae
======================================================================

From 1984 until 1986 I studied reproduction of Millepora spp. in Guam.
My initial interest was in determining whether reproduction is
seasonal. Millepora spp. have unique reproductive structures in the
calcium carbonate skeleta (hard parts), the ampullae, which surround
the developing medusa and gametes. These ampullae are only present
when the reproductive zooids, the medusae, are produced, and are
filled in within a matter of days after the medusae have been
liberated. Thus, the presence of ampullae in hard parts specimens is a
sign that the colony was reproductively active at the time of
collection, and their absence a sign, likewise, that the colony was
not reproductively active. I was determined to track reproductive
effort over time using these ampullae as markers. Later on, as the
study of Millepora spp. took on a life of its own, it indeed became
apparent that Millepora spp. are highly seasonal, and other aspects of
their biology, and that of associated species, piqued my interest.

Specimens of hard parts were collected at irregular intervals
beginning in September 1984 until fall 1986. Beginning somewhat after,
some specimens were decalcified, and tissues embedded in wax for
sectioning. Colonies at certain reefs were numbered and labelled to
enable samples to be taken, repeatedly from the same colony.

In both 1985 and 1986, Millepora platyphyla shed medusae about three
or four days after full moon in early April, in what appeared to be
the first event of a summer reproductive season. Each of these events
(except one, see below) was apparently highly synchronized on Guam,
with apparently substially all the ripe Millepora platyphyla colonies
on Guam reefs shedding medusae on the same night.

The first event of each of these seasons was striking to observe on
the reef. Each "spawning" was presaged by an abrupt change in the
appearance of a preponderance of Millepora platyphyla colonies on Guam
reefs: they turned a richer, darker brown. This change of coloration
seemed to be poorly correlated with reproductive condition; color was
apparently not correlated with reproductive condition in other
months. On many (but not all) of the darker colonies could be seen a
myriad of minute white rings about 1 mm in diameter, contrasting with
the background of dark brown. These white rings evidenced the opening
of the ampullae. Within approximately a week after this color change,
the colonies shed their burdens of medusae (bearing female and male
gametes) in a synchronous ”spawning” event. I observed shedding of
medusae in ziploc bags containing colony fragments at about sunset.
Each colony produced either male or female medusae, as Hickson
reported.


Swarming does not occur a uniform number of days after the full moon,
but usually somewhere between one and four days after full moon. Only
once were medusae observed to swarm on

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