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The mission of the International Association of Bryologists (IAB), as a society, is to strengthen bryology by encouraging interactions among all persons interested in byophytes.

Thursday, September 17, 2009

BRYONET: Hornworts sperm

http://www.bluetier.org/liverwort2/hornwort-5.JPG
BRYONET
-------- Original Message --------
Subject: Hornworts
Date: Thu, 17 Sep 2009 14:42:22 +1000
From: Blue Tier Mail <mail@bluetier.org>
I had the extraordinary fortune to witness what I assume is a rare event
- that of hornwort antheridium expelling sperm. I managed to record
this, pix at http://www.bluetier.org/liverwort2/hornwort-5.JPG.
I had brought home sample tissue several weeks ago to try identify
species, and managed to keep it alive and watch the sporophytes grow.
It is probably Phaeoceros carolinianus but I will wait to observe spores
before confirming this.
I placed a small section of tissue on a slide and was amazed to find
that at least 2 of the antheridium were expelling fluid and sperm (quite
forcibly) through what must be ruptures on the skin. This went on for
at least over an hour when the flow slowed down somewhat.
The fluid is emerging from roughly 120 degree position in the image.
What you see below the antheridium as dots are the sperm cells but I am
unable to do justice to these with a decent pix.
Several questions come to mind:
a) is the fluid stored in some form of container for this purpose or is
there a pumping action expelling fluid through the rupture?
b) only a few of the sperm containing cells had released their contents
which seems to be wasteful; under natural conditions do all all the
sperm get expelled?
I had hoped to observe the specimen several hours later but alas it had
dried up partially and deformed making it impossible to get a plane to
focus on. However vast quantities of sperm were swimming around in the
still-moist parts.
I trust you find this of interest.
Regards, Tom Thekathyil

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