Jim Dombroskie Born in K-W Born in K-W Attended high school at Eastwood Collegiate Attended high school at Eastwood Collegiate Worked for a couple of years Worked for a couple of years Attended Sir Sandford Fleming Attended Sir Sandford Fleming Hope to graduate from here (someday!) Hope to graduate from here (someday!) Work for Crone geophysics Work for Crone geophysics

What are they? One celled organism One celled organism Solitary or colonial Solitary or colonial Siliceous Siliceous Planktic and Benthic forms Planktic and Benthic forms Over species Over species Can be found in almost any moist place Can be found in almost any moist place Eukaryotic Eukaryotic Grovea pedalis

Environment Freshwater -puddle -ditch -tree (moss) -lagoon, river, etc Freshwater -puddle -ditch -tree (moss) -lagoon, river, etc Marine -benthic and planktic areas Marine -benthic and planktic areas

Diatom Morphology Frustule (skeleton) Frustule (skeleton) -hypotheca -hypotheca -epitheca -epitheca -can have varying shapes -can have varying shapes Punctae Punctae Raphe (groove) Raphe (groove) No flagella No flagella

Classification Phylum Bacillariophyta Phylum Bacillariophyta Class Diatomatae Class Diatomatae Order Centrales Order Centrales Order Pennales Order Pennales Although some put it in the phylum Chrysophyta Although some put it in the phylum Chrysophyta

Order Centrales Centric Centric Dominate marine environments Dominate marine environments Cret. To Rec. Cret. To Rec. Radially symmetrical Radially symmetrical -although they can have varying shapes -although they can have varying shapes

Order Pennales Pennate (elongate) Pennate (elongate) Dominate non-marine environments Dominate non-marine environments Paleocene to Recent Paleocene to Recent Bilaterally symmetrical Bilaterally symmetrical -features perpendicular to long axis -features perpendicular to long axis

Reproduction Asexual Asexual Mitosis Mitosis Alternation between both Alternation between both Progressive decrease in size Progressive decrease in size

Reproduction Sexual Sexual Meiosis Meiosis Gametes released and combined with another Gametes released and combined with another Zygote Zygote

Importance Responsible for 20%-25%of all carbon fixation (CO2 + H2O = sugars) Responsible for 20%-25%of all carbon fixation (CO2 + H2O = sugars) Contribute to atmospheric oxygen Contribute to atmospheric oxygen Major component of plankton (source of food for many organisms Major component of plankton (source of food for many organisms Age dating (many have short time ranges) Age dating (many have short time ranges) Dynamite, abrasive, filter, etc. Dynamite, abrasive, filter, etc. Grass of the Sea Grass of the Sea

Hazardous genus Pseudonitzschia genus Pseudonitzschia Domoic acid Domoic acid binds to the glutamate receptors in the brain where it causes nerve cells to transmit impulses continuously until the cells die 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. eutrophication processes occurring along our coasts some algae (diatoms!) blooms have caused mass pollution and starvation.

References angallery/diatom.html angallery/diatom.html angallery/diatom.html angallery/diatom.html html 07.html 07.html 07.html m m m m mmm.html mmm.html mmm.html mmm.html