fungus-like protists

FUNGUS-LIKE FUNGUS-LIKE PROTISTSPROTISTSPhylum MyxomycotaPhylum Myxomycota

Phylum AcrasiomycotaPhylum AcrasiomycotaPhylum OomycotaPhylum Oomycota

http://www.nytimes.com/2011/10/04/science/04slime.html?_r=5&pagewanted=all&

CHARACTERISTICS

1. why fungus-like?• appearance• mode of nutrition

2. with centrioles

3. no chitin in cell walls

4. non-photosynthetic

5. 2-stage life cycle• spore-bearing mold-like stage • free-living amoeba-like stage

Stemonitis fusca

http://tywkiwdbi.blogspot.com/2011/11/slime-mold.html, http://www.nationalgeographicstock.com/comp/04/442/1030283.jpg

Comatricha typhoides

Dominant state near rich sources of food

(phagocytic)

Cells aggregate into a slimy mass

when food is scarceand moves to a better location

http://www.nsf.gov/od/lpa/news/03/pr03106_images.htm

Fruiting bodySpore-bearing structure

SLIME MOLDS• Phylum MyxomycotaAcellular slime molds

• Phylum AcrasiomycotaCellular slime molds

Phylum MyxomycotaAcellular or plasmodial slime molds

• plasmodium • large cytoplasmic

mass (multinucleate)• feeding stage

• unfavorable conditions: “fruiting”• sporangia spring up

from plasmodium• meiosis haploid

spores flagellated gametes →diploid zygote (sexual reproduction) →*diploid amoeboid cells

• e.g. Physarumhttp://biodidac.bio.uottawa.ca

http://home.sandiego.edu/~gmorse/2009BIOL221/Study_guide2/plasmodial.jpg

Physarum polycephalum

Comatricha typhoides

Lycolaga epinendrum“wolf’s milk”

Stemonitis splendens“chocolate tube slime”

Arcyris denudata“carnival candy slime”

Brefeldia maxima“tapioca slime”

Tubifera ferruginosa“red raspberry slime”

http://xkcd.com/877/ , http://www.uknature.co.uk/F.septica.jpg, http://i55.tinypic.com/313k32b.jpg, http://i56.tinypic.com/flly6t.jpg

Phylum Acrasiomycotacellular slime molds

• pseudoplasmodium• separated by cell

membranes • cell aggregation

• slug-like form• migrates to form

fruiting body • spores by mitosis

• e.g. Dictyostelium discoideum

Phylum Oomycotawater molds/downy mildew

• cellulosic cell wall• live on organic

matter in water, plant parasites on land

• hyphae finely-branched single-celled filaments

• coenocytic/aseptate no walls between cells

• motile spores

Phytophthora infestans http://www.bluepointenvironmental.com/wp-content/uploads/2012/01/coenocytic-hyphae-60x-LP.jpg

Significance

• decomposers• food source of other organisms

• parasites of plants (grapes, tomatoes, potatoes) and animals

• used to plan routes (shortest distance)

• rich areas for biological study

http://www.gardencentre.ie/blog/wp-content/uploads/2012/05/potato-blight.jpg, http://media.treehugger.com/assets/images/2011/10/tokyo-mold-railway.jpg