Fungi and Slime Molds
March 11, 2008
Chytriomyces sp.
The series for UBC Research Week continues. Today's write-up and photos are courtesy of Toko Mori. Toko writes:
My name is Toko Mori, a first-year graduate student in the Berbee Lab at the University of British Columbia. I study chytrid fungi, microscopic fungi that mainly live in freshwater. I especially focus on the local chytrids that parasitize freshwater microscopic algae. My long-term research goal is to create a tree of life of chytrids that parasitize algae and to see if there is any coevolutionary relationship between the species of parasitic chytrids and those of their host algae. I collected this chytrid on an alga, Vaucheria, from Burnaby Lake (Burnaby, BC) in August 2007. I have cultured it on agar and also co-cultured it with Vaucheria since then.
Since it seems that this is the first entry of chytrids in the Botany Photo of the Day, let me explain what they are. Chytrids are fungi, although they look quite different from mushrooms and molds, which we often think of as fungi. There are about one thousand species of chytrids which form the Phylum Chytridiomycota. Being the only group of fungi which reproduce by motile cells called zoospores (shown in picture 4), chytrids are considered to have diverged from the other fungi very early in their evolutionary history. Having motile spores gives them reproductive advantage in water. However, this is a double-edged sword; chytrids are unable to reproduce without moisture and thus bound to aquatic habitats.
Chytrids have recently attracted public attention as a cause for the population decline of amphibians. However, not all the chytrids are amphibian pathogens. To the contrary, many chytrid species are decomposers of organic matter in ponds and lakes, or parasites of microscopic invertebrates or algae, as in this case. Not much is known about their ecological roles.
Now let me explain these pictures. You are witnessing the moment of zoospore release, the highlight of their life history. The small round structure on the algal filament in picture 1 is a mature sporangium, where zoospores are produced. (The big bulge at the right end is a part of the alga, which I will explain later.) You can see the sporangium filled with small dots, each representing a zoospore. Five minutes later, the zoospores start to leave the sporangium, probably triggered by the sudden change in temperature caused by the intense light from the microscope. The change in pH of the surrounding water (when transferred from culture to a drop of distilled water on a slide) may also be the trigger. For a few minutes after the release, zoospores swarm just outside of the sporangium, until they start to swim away as in picture 3. As you may see in picture 4, the zoospores (ca. 4µm in diameter) have a flagellum like that of animal sperm. Eventually these zoospores stop swimming, retract their flagellum and encyst on a suitable substratum if they find one. Then they themselves will grow into a new sporangium, produce zoospores inside by mitosis, and start a new cycle of asexual reproduction.
A note for this alga. To co-culture this chytrid with its host, I received the culture of the host algal species, Vaucheria sessilis, from the Canadian Center for the Culture of Microorganisms at UBC. Vaucheria is unusual in that it lacks cell walls except when making reproductive structures; this entire filament seen here is one cell. The bulging end was formerly a spore, from which this algal filament grew.
Species identification is an important part of my research. Correct identification is the first step to making a tree of life. However, species identification of chytrids can be often difficult due to their simple body structure - there are not many morphological characters to study, at least on the light microscopy level. These days researchers combine molecular data and electron microscopy, together with traditional morphology. I have identified this chytrid down to the genus Chytriomyces, based on the light microscopic level morphology and molecular data.
Posted by Daniel Mosquin at 2:13 PM| Comments (13)
November 30, 2007
Aseroe rubra
Another thank you to David M. aka petrichor@Flickr (and Kipili.com) for sharing an image via the BPotD Flickr Group Pool (original). Appreciated once again, David.
Starfish fungus or sea anemone fungus has previously been featured on BPotD here: Aseroe rubra. Today's photograph illustrates the fungus a bit later in development – considering how quickly stinkhorns develop and fade, I suspect these individuals are only a day further along than the starfish fungus in the previous entry.
Posted by Daniel Mosquin at 8:24 AM| Comments (7)
November 28, 2007
Phallus impudicus
A thank you to mudman@UBC Botanical Garden Forums for sharing this scan (original thread). Much appreciated!
Common stinkhorn can be found in the temperate forests and rich-soiled gardens of North America and Europe (and, according to Wikipedia, possibly southeast Australia). Of course, this image isn't of the mature fungus (see: MushroomExpert's Phallus impudicus for photographs). Instead, this is a cross-section scan of the immature stinkhorn, described succinctly in Wikipedia's entry on Phallus impudicus:
“Sometimes called the witch's egg, the immature stinkhorn is whitish and egg-shaped and up to 6 cm (2 in) in diameter. On the outside is a thick whitish volva, also known as the peridium, covering the olive-coloured gelatinous gleba. It is the latter which contains the spores and which later stinks and attracts the flies; within this layer is a green layer which will become the 'head' of the expanded fruit body; and inside this is a white structure called the receptaculum (the stalk when expanded), which is hard, but with an airy structure like a sponge. The eggs become fully grown stinkhorns very rapidly, over a day or two.”
For those who ask such things, yes, it is edible at this young stage, but it is not commonly eaten.
Lastly, a reminder that if you're a fan of fungi and lichens, there are two areas of the forums dedicated to these beasties: Fungus and Lichen Appreciation & Discussion and Fungus and Lichen Identification.
Posted by Daniel Mosquin at 5:44 AM| Comments (8)
October 16, 2007
Laetiporus gilbertsonii
A thanks to Mike Bush (former director of Lotusland) for sending along today's photograph in an email with the subject line “30mph stopper!”. Mike now has a weblog, BushBlog where he has written about this Fungus Amongus in Santa Barbara and then provides an update on its fate (hint: a dinner plate).
The eastern North American species of chicken-of-the-woods has previously been featured on BPotD, Laetiporus sulphureus. Prior to the start of this decade, conventional thought was that all Laetiporus in North America were one species, L. sulphureus. However, a closer look revealed that there were multiple species, and so Laetiporus sulphureus has been split up. In the case of today's fungus, Laetiporus gilbertsonii is to-the-eye indistinct from L. sulphureus. Grown in culture, however, it will not reproduce with the eastern North American L. sulphureus, making it biologically distinct. By some definitions, that is enough to classify it as a separate species.
In his weblog entry, Mike mentioned that this fungus was growing on a Eucalyptus. Knowing the substrate a fungus is growing on is often useful in identifying it, and that's the case here, as it helped eliminate the conifer-loving Laetiporus conifericola. For more on Laetiporus, visit Michael Kuo's page on Laetiporus sulphureus and relatives. The Fungi of California site provides additional information and more photographs: Laetiporus gilbertsonii.
Photography resource link: The Garden at Night: A Photographic Journey by photographer Linda Rutenberg. Linda visited 19 botanical gardens in the US and Canada and photographed them at night (and yes, UBC Botanical Garden is one of them!). I've found two newspaper articles about her project and book, if you'd like to read more: Moonlight transforms the ordinary into things of beauty via the Montreal Gazette and 'Lady of the Night' Rutenberg vividly captures world of darkness from the Montreal Chronicle. (PS: I've added the book to UBC BG's Amazon store (USA and elsewhere | Canada | UK) if you are interested in purchasing it. I'll be buying a copy.)
For those readers in California, I note that Linda is giving a night photography workshop in San Francisco and lectures at Descanso and Huntington gardens.
Posted by Daniel Mosquin at 7:00 AM| Comments (5)
October 3, 2007
Tricholomopsis rutilans
Monika F (aka monika & manfred@Flickr) is the contributor of today's photograph (original via BPotD Flickr Pool). Thank you!
One of the common names for this species isn't well-illustrated by this photograph of a mature specimen. A photograph of younger individuals on the Fungi of California site, however, fully justifies the common name: plums and custard. Also known as red-haired agaric, Tricholomopsis rutilans is native to coniferous woodlands of the Northern Hemisphere (and before anyone asks, it's only barely edible).
Michael Kuo and Roger Phillips both provide descriptions of this fungus. If you're interested in more photographs, the folks at MushroomObserver.org have a series of images on Tricholomopsis rutilans. The Illinois Mycological Society provides a key-based description of this fungus, as well.
In BPotD news, a photograph from a couple years ago is appearing in film! This image of the golden spruce makes a few-second cameo in Mark Leiren-Young's “The Green Chain” (warning: turn your speakers down). The Green Chain recently debuted at the Montreal World Film Festival and is now playing at the Vancouver International Film Festival, where it's been nominated for a “Climate for Change” award. I'll let you know what I think of the film next week after viewing it, but from what little I've seen so far, it has me intrigued (here's the first review via The Green Chain Weblog).
If you're interested in forestry issues, you should also be following Mark's “Trees and Us” podcasts on The Tyee: Trees and Us with Severn Cullis-Suzuki, Why Humans and Nature Collide with John Vaillant and Why Rocket Science is Easier Than Forestry with Jean-Pierre Kiekens.
Posted by Daniel Mosquin at 12:00 AM| Comments (5)
September 28, 2007
Geastrum sp.
Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel
Thank you to Anne from Alberta (aka annkelliott@Flickr) for sharing these photographs with BPotD (original 1 | original 2 | BPotD Flickr Group Pool). Much appreciated!
The genus Geastrum is one of 8 genera within the family Geastraceae (the earthstar family). Broadly (and unscientifically) speaking, these can be placed into the category of puffballs.
Posted by Daniel Mosquin at 7:40 AM| Comments (3)
September 13, 2007
Mycena interrupta
Botany Photo of the Day will have brief written entries on weekends, holidays and my vacations from April through September. – Daniel
Ken Beath, aka kjbeath@Flickr is the person to thank for today's photograph (original via the BPotD Flickr Group Pool). Do visit Ken's Australia photo galleries if you've the time! Thanks, Ken.
Measuring approximately 1cm across, pixie's parasol is a diminutive mushroom of fallen wood substrates in moist forests of Australia, New Zealand and Chile. The Royal Botanic Gardens Melbourne had a fungus of the month site for two and a half years, and Mycena interrupta was featured. Special mention was made of the Gondwanan distribution pattern.
Posted by Daniel Mosquin at 12:00 AM| Comments (14)
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Botany Photo of the Day and all associated images are licensed under a Creative Commons License.
Botany Photo of the Day is a project of the UBC Botanical Garden and Centre for Plant Research, located in Vancouver, British Columbia Canada. UBC BGCPR is a department of the Faculty of Land and Food Systems within The University of British Columbia.