Water Molds and Simple Fungi Oomycota, Chytridiomycota, Zygomycota

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Water Molds and Simple FungiOomycota,
Chytridiomycota, Zygomycota
EKU General Botany Lab
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Saprolegnia (Oomycota)
antheridial hyphae
oogonium with eggs inside
vegetative hyphae (2n and coenocytic)
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Saprolegnia reproduction
Asexual
Sexual
(resistant zygote)
(Antheridia and antheridial hyphae are basically
interchangeable terms.)
Zoosporangium
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Phlyctochytrium
a holocarpic chytrid
mycelia
rhizoidal hyphae
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Allomyces
a filamentous chytrid
coenocytic hyphae
resistant sporangia (meiosporangia)
mitosporangia
The true colors of this organism have
been greatly distorted by the technique used to
make the permanent slide from which this photo
was taken. (See the next slide.)
Is this the sporophyte (2n) phase, or the
gametophyte (n) phase?
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The last slide was of preserved material.Here is
a better slide--of living material.
photo by Ross Clark
This is the diploid (2n) phase of Allomyces. All
of the sporangia in this photo are resistant
meiosporangia. No thin-walled mitosporangia are
visible. These resistant sporangia eventually
will detach and float to the bottom. As
spring arrives, meiosis will occur inside the
sporangia and they will release haploid (n)
meiozoospores.
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Allomyces gametangia
photo by Ross Clark
In Allomyces, the male and female gametangia
usually occur in pairs, with one sex above the
other. In the picture above, you can see the
brownish male gametangia above the clear female
gametangia. The female gametangia have already
released their gametes. The bright white spots
are the exit papillae where the female gametes
left the gametangia.
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Rhizopus nigricans (Zygomycota)

• Black Bread Mold

Sporangium
Sporangiophores
Spores
Columella
Rhizoids
Mycelium (coenocytic)
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Rhizopus nigricans reproduction(Zygomycota)
suspensor
asexual phase
sexual phase
diploid
suspensor
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Some chytrid pictures
chytrid on diatom
a holcentric chytrid
More chytrids!
chytrids on spirogyra cell
Polymyxa, a chytrid-like organism, but not a
chytrid (has 2 anterior whiplash flagella)
Diagram of chytrid zoospore one
posterior whiplash flagellum
Dont forget some chytrids, such as Allomyces,
have filamentous hyphae.