Collection #: 16
Scientific Name: Pediastrum boryanum var. cornutum
Phylum: Chlorophyta
Order: Chlorococcales
Family: Hydrodictyaceae
Common Name: N/A
Location: Hiram
Habitat: Small pond
Date of collecting: September 21st
Collector: Willa
Notes: Neat circular colony with tooth like cells
How did I key this out:
Fig.1 Colony under microscope
The following steps is how I went through the keys:
1. (B) Plants microscopic or if visible to the naked eye it is normallly because they are present as a mass - but still requiring microscopic observation to determine the more detailed morphology (3)
3. (B) Cells individual or in groups that may be regular or irregular in shape but not forming a filament, stand or ribbon (56)
56. (B) Cell pigments localized in chloroplast (68)
68. (A) Cells arranged in colonies of definite shape (69)
69. (B) Cells of colony without flagella, colony non-motile (76)
76. (B) Cells do not have silica walls. Main storage product starch (81)
81. (B) Cells not elongate like a cigar, often more spherical, cubical, crescent-shped or at the most short cylinders. Can form plate-like colonies. Stellate colonies are not formed. (82)
82. (B) Cells not within a definite mucilaginous envelope (91)
91. (A) Colonies either spherical, oval or a flat disc (92)
92. (A) Cells of colony form a flat disc (93)
93. (A) Colony free floating (Pediastrum)
Description of the species:
Pediastrum forms characteristics flat plate-like colonies which are common in lakes, ponds and slow flowing rivers that are nutrient-rich. The cell walls are often quite tough and persist for some time after the contents have disappeared. There are many species. Can, if present in large numbers, impart unwanted odour to drinking waters. Chlorophyta.
Colony consist of up to 32 cells; cells dimensions 5-27 x 4-24 µm, marginal cells slightly to deeply notched and with two projections lying almost parallel to each other, typically projections equal to or shorter than cells bearing them; inner cells polygonal, with triangular or lens-shaped intercellular spaces.
Collecting and keying story:
Pediastrum forms characteristics flat plate-like colonies which are common in lakes, ponds and slow flowing rivers that are nutrient-rich. The cell walls are often quite tough and persist for some time after the contents have disappeared. There are many species. Can, if present in large numbers, impart unwanted odour to drinking waters. Chlorophyta.
Colony consist of up to 32 cells; cells dimensions 5-27 x 4-24 µm, marginal cells slightly to deeply notched and with two projections lying almost parallel to each other, typically projections equal to or shorter than cells bearing them; inner cells polygonal, with triangular or lens-shaped intercellular spaces.
Collecting and keying story:
This specimen was found in the water sample provided by Willa. There were a ton of different types of algae in that water sample, and I picked this one because it looks cute. At first we thought the life form for this specimen was unicellular, but failed to key it out, so we decided that this is in a colony. After keyed to genus, a picture plate was provided by the book for us to key it to species.
Phylum, order and family name cited from:
http://www.algaebase.org/search/species/detail/?species_id=34691&-session=abv4:42F948D809f6b25045PhRI60E2F5
http://www.algaebase.org/search/species/detail/?species_id=34691&-session=abv4:42F948D809f6b25045PhRI60E2F5
Keys cited from:
Freshwater Algae by Edward G. Bellinger and David C. Sigee
Description cited from:
Freshwater Algae by Edward G. Bellinger and David C. Sigee
http://dbmuseblade.colorado.edu/DiatomTwo/sbsac_site/species.php?g=Pediastrum&s=boryanum%20cornutum
Freshwater Algae by Edward G. Bellinger and David C. Sigee
Description cited from:
Freshwater Algae by Edward G. Bellinger and David C. Sigee
http://dbmuseblade.colorado.edu/DiatomTwo/sbsac_site/species.php?g=Pediastrum&s=boryanum%20cornutum
No comments:
Post a Comment