PhycoLec - PreLims

• Algae was used to be called "thallophyte" in botany
• Algae's old name is "cryptogram", which refers to spore-bearing, non-flowering plant-like organisms
• Characteristics of Algae:

  • Photosynthetic with chlorophyll a
• Major Algal Groups (Phylum):

  • Cyanobacteria (Cyanophyta)
  • Glaucophytes (Glaucophyta)
  • Green Algae (Chlorophyta)
  • Red Algae (Rhodophyta)
  • Brown Algae (Phaeophyta)
  • Diatoms (Bacillariophyta)
  • Dinoflagellates (Dinophyta)
  • Euglenoids (Euglenophyta)
  • Yellow-Green Algae (Xanthophyta)
  • Cryptophytes (Cryptophyta)
  • Golden-Brown Algae (Chrysophyta)
• Ecological Significance of Algae:

  • Many algae are planktonic
  • Habitats of algae include freshwater, marine, soil, epiphytes, and symbiosis
  • Phytoplankton are microscopic, floating, autotrophic organisms present in illuminated surface waters
  • Phytoplankton serve as the base of the aquatic food chain
  • Phytoplankton absorb 50% of global atmospheric carbon dioxide (CO2)
• Environmental Functions and Applications of Algae:

  • Ecosystem functions include reducing carbon dioxide levels, producing oxygen, and serving as the base of the aquatic food chain
  • Algae capture fertilizer runoff in farmlands for pollution control
  • Algae are researched for biofuel production
• Common Name, Genus, Major Group (Phylum), and Food Supplement:

  • Spirulina, Cyanobacteria (Cyanophyta)
  • Sea Grape (Edible Seaweed), Chlorella and Caulerpa, Green Algae (Chlorophyta)
• Historical Development of Algae:

  • Carl Linnaeus divided the plant kingdom into classes and proposed 14 genera of algae
  • Jean Vincent Feix Lamouroux separated algal groups based on color
  • William Henry Harvey divided algae into four major divisions based on pigmentation
• First Sightings and Observations:

  • Anton van Leeuwenhoek found green clouds in lake water
  • Joseph Banks found "sea saw-dust" assumed to be Oscillatoria or Trichodesmium
  • William Scoresby described diatom chains in opaque green waters
  • Joseph Dalton Hooker observed microscopic life from seawater and zooplankton guts
• Improvement in Sampling and Detection:

  • Johannes Muller used a tow net to collect samples
  • Charles Atwood Kofoid and Walter H. Lohmann noted the smallest phytoplankton were missed in large mesh sizes of nets
  • Mary Parke discovered unialgal culture of flagellated phytoplankton as food for oyster larvae
• Oceanography and Distribution:

  • Alister Hardy used a continuous plankton recorder to show patchy distribution of algal blooms
  • Alexander Wrigley & Robert Home did aerial photography and ocean color studies
  • John Douglas Strickland related phytoplankton distribution to high-nutrient upwelled waters
  • T. Platt DVS Rao proposed estimates of phytoplankton productivity in the oceans equal to that of land plants
• Characteristics of Algae:

  • Performs oxygenic photosynthesis