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Jim Dombroskie. Born in K-W Attended high school at Eastwood Collegiate Worked for a couple of years Attended Sir Sandford Fleming Hope to graduate from here (someday!) Work for Crone geophysics. DIATOMS. What are they?. One celled organism Solitary or colonial Siliceous
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Jim Dombroskie • Born in K-W • Attended high school at Eastwood Collegiate • Worked for a couple of years • Attended Sir Sandford Fleming • Hope to graduate from here (someday!) • Work for Crone geophysics
What are they? • One celled organism • Solitary or colonial • Siliceous • Planktic and Benthic forms • Over 60 000 species • Can be found in almost any moist place • Eukaryotic Grovea pedalis
Environment • Freshwater -puddle -ditch -tree (moss) -lagoon, river, etc • Marine -benthic and planktic areas
Diatom Morphology • Frustule (skeleton) -hypotheca -epitheca -can have varying shapes • Punctae • Raphe (groove) • No flagella
Classification • Phylum Bacillariophyta • Class Diatomatae • Order Centrales • Order Pennales • Although some put it in the phylum Chrysophyta
Order Centrales • Centric • Dominate marine environments • Cret. To Rec. • Radially symmetrical -although they can have varying shapes
Order Pennales • Pennate (elongate) • Dominate non-marine environments • Paleocene to Recent • Bilaterally symmetrical -features perpendicular to long axis
Reproduction • Asexual • Mitosis • Alternation between both • Progressive decrease in size
Reproduction • Sexual • Meiosis • Gametes released and combined with another • Zygote
Importance • Responsible for 20%-25%of all carbon fixation (CO2 + H2O = sugars) • Contribute to atmospheric oxygen • Major component of plankton (source of food for many organisms • Age dating (many have short time ranges) • Dynamite, abrasive, filter, etc. • Grass of the Sea
Hazardous • genus Pseudonitzschia • Domoic acid • binds to the glutamate receptors in the brain where it causes nerve cells to transmit impulses continuously until the cells die • eutrophication processes occurring along our coasts some algae (diatoms!) blooms have caused mass pollution and starvation.
References • http://hjs.geol.uib.no/diatoms/Marbles/index.html-ssi • http://www.microscopy.fsu.edu/primer/techniques/hoffmangallery/diatom.html • http://hjs.geol.uib.no/diatoms/ • http://www.visualsunlimited.com/browse/vu315/vu315607.html • http://earth.leeds.ac.uk/electronoptics/set3/diatom_c.htm • http://www.ucmp.berkeley.edu/chromista/diatoms/diatommm.html