Algae Research Project
Jigsaw
Teacher Background:
Algae, an Introduction:
Algae…it is a term that often illicits images of murky swimming pools, spooky, sludge covered
farm ponds, algal blooms and fish kills, slippery rocks in a stream, or the obscured, slimy glass
of an aquarium. Unfortunately, the ambiguous term “algae” does not do justice to the
tremendous amount of diversity found in these aquatic photosynthesizes (an estimated 250,000+
species), nor does it provide insight into the remarkable range of shapes and sizes of these
organisms (stretching from prokaryotic cells that are a few microns in width to marine kelps that
can be greater than 50 meters in length). Furthermore, despite the negative connotations often
attached to algae, it is important to note that these organisms often make up the foundation of
aquatic food webs and are critical to the world around us.
The term alga (algae: plural) is used to reference a heterogeneous conglomerate of nonembryophyte (i.e., not included with the bryophytes or vascular plants), primarily photosynthetic
(though some have heterotrophic capacities), and generally aquatic organisms. One of the
greatest challenges for a beginning phycologist (someone who studies algae) is understanding
that the term algae actually references many different groups of organisms, most of which are not
closely related. Technically known as a polyphyletic assemblage, the term algae represent an
unnatural grouping of organisms. Consider if we created a new group of organisms and the
characteristic used to define this group was the ability to fly (the Phylum Flyophyta). Examples
of organisms which we would place in this could include birds, bats, butterflies, dragonflies,
flying squirrels, and superheroes. Now while all of these taxa have the capacity to soar through
the air they employ strikingly different mechanisms by which they achieve flight (or do not,
considering the flying squirrel simply glides). Furthermore, the lack of common ancestry makes
it difficult to determine the relationships between these various groups. The different groups of
algae are similar in that they share some very general characteristics, but often lack a common
ancestry, as well as operate in a very different manner from one another. However, it is unlikely
that that the term algae will disappear anytime soon from the human vernacular. Thus, it is
important to realize that they are simply a collection of relatively simple photosynthetic life
forms.
The majority of algae are eukaryotic in nature and are often presently lumped into the Kingdom
Protista (another unnatural group). In the future it is likely that these various groups will be
broken into their own kingdoms (joining the existing Animalia, Fungi, and Plantae). There is
also an ecologically and economically (good and bad) group of prokaryotic algae, the
Cyanobacteria (blue-green algae). Below you will find a simplified listing of the major groups
of algae:
© 2010, Ohio Northern University: Dr. Kenneth Reid, Dr. Debra Gallagher and Dr. Robert Verb
Domain Bacteria

Phylum Cyanophyta (Cyanobacteria)
Domain Eukarya

Kingdom Protista
o Phylum Bacillariophyta (Diatoms)
o Phylum Chlorophyta (Green Algae)
o Phylum Chrysophyta (Golden Algae)
o Phylum Dinophyta (Dinoflagellates)
o Phylum Euglenophyta (Euglenoids)
o Phylum Phaeophyta (Brown Algae)
o Phylum Rhodophyta (Red Algae)
o Phylum Xanthophyta (Yellow-green Algae)
Not all of these groups are major contributors to the algal diversity and biomass on the planet
and may not be discussed in great detail. In addition, there are several other obscure phyla of
eukaryotic algae that will not be included in these modules.
Algae show tremendous amounts of variation in terms of the morphology (shape) of their body
(also known as a thallus). Most commonly encountered forms include:
 Unicellular: Solitary, individual cells. May be motile or nonmotile.
 Colonial: Assemblage of individual cells. May be variable or predictable number of cells
involved.
 Filament: Cells are attached together in a chain like manner. May be branched or
unbranched. Filaments may also be one cell or many cells thick.
 Ceonocytic or aseptate forms: Often filaments lacking individual cell units, the organism
persists as a giant individual cell.
 Parenchymous/Pseudoparenchymous: Highly derived forms with many shapes and sizes
ranging from microscopic to large macroscopic seaweeds.
We do not know how many species of algae exist in the world. Current estimates of described
species range from 250,000- 300,500 species, but some researcher think that the number of
undiscovered species is in the millions. Even with so many undiscovered species we can still
appreciate the ability of algae to grow anywhere in the world.
Algal Habitats
Algae are abundant in most bodies of water including marine, brackish, and freshwater systems,
but also extreme/unusual environments such as snow, ice, geysers, acidic zones, and deserts. In
addition, algae are often involved in symbiotic relationships with other organisms including
© 2010, Ohio Northern University: Dr. Kenneth Reid, Dr. Debra Gallagher and Dr. Robert Verb
lichens, coral reefs, sponges, cycads, and sloths. Since inland, freshwater system are the focus of
this module, a generalize listing of habitat types follow:
Lotic Systems: Refers to habitats with standing or sluggish waters. Attached algae are abundant
in the shallow parts and often exist in the open water as floating/swimming phytoplankton.
Common examples include ponds and lakes.
Lentic Systems: Refers to habitats with moving or flowing waters. Attached algae are common
in systems where light can reach the bottom (benthos). The densest abundances of algae can be
found on hard substrates such as rocks, rather than those that can be easily disturbed (i.e., sands,
mud). Common examples include streams and rivers.
Wetland Environments: A broad, encompassing term referring to habitats that must be saturated
with moisture either permanently or seasonally. Algae often exist on the benthos, but also as
phytoplankton and between emergent plants such as cattails. Common examples include, but are
not limited to, bogs, fens, marshes, and swamps.
Temporary, Vernal, or Ephemeral: These unique systems only contain water for a few
days/weeks out of the year. Despite their short existence, they are full of unique algae. These
can be natural or artificial in nature. Examples include ephemeral streams, vernal pools, ditches,
springs, teasel leaves, bird baths, buckets, and tire tracks.
Terrestrial: Many algae can exist out of water, even in places when low quantities of moisture
are available.
Anthropogenic Uses of Algae:
For thousands of years humans have utilized algae as fertilizer, food, and feed for livestock.
Even today many species are still used for these functions. There are also several economically
important products extracted from algae including agar, algin, carrageenan, and pigmentation.
Algae are also often used as living monitors serving as bioindicators of the health of aquatic
ecosystems. Recently, with rising concerns of climate change and shortages of non-renewable
fossil fuels (i.e., petroleum), there have been many ventures into the realm of biofuels. Algae are
of particular interest because they have the potential to produce more biomass per unit area in a
year than any other form of biofuel biomass (i.e., soybeans, palm, corn). However, the field of
algal based biofuels is in its infancy, with many unresolved ecological and technical issues. The
primary objective of these successive modules is to introduce students to the field of algae and
eventually to the culturing, harvesting, and processing of algal biomass to generate viable biofuel
products.
© 2010, Ohio Northern University: Dr. Kenneth Reid, Dr. Debra Gallagher and Dr. Robert Verb
Additional Web Based Algal Information
http://www.uctv.tv/search-details.aspx?showID=11931
http://vis-pc.plantbio.ohiou.edu/algaeimage/imageindex.htm
http://www.ucmp.berkeley.edu/protista/rhodophyta.html
http://www.ucmp.berkeley.edu/chromista/bacillariophyta.html
http://www.ucmp.berkeley.edu/chromista/phaeophyta.html
http://www.ucmp.berkeley.edu/chromista/xanthophyta.html
http://www.ucmp.berkeley.edu/greenalgae/greenalgae.html
http://www.ucmp.berkeley.edu/protista/dinoflagellata.html
http://www.umich.edu/~phytolab/GreatLakesDiatomHomePage/top.html
http://www.turtles.org/limu/limu.htm
http://www.keweenawalgae.mtu.edu/
http://www.seaweed.ie/
http://www-cyanosite.bio.purdue.edu/index.html
http://www.desmids.nl/
http://www.fossilmuseum.net/Tree_of_Life/Stromatolites.htm
http://www.bgsu.edu/departments/biology/facilities/algae/index.html
http://euglena.msu.edu/
http://www.psaalgae.org/website/resources/educational.html
http://www.mbari.org/staff/conn/botany/phytoplankton/phytoplankton_diatoms.htm
© 2010, Ohio Northern University: Dr. Kenneth Reid, Dr. Debra Gallagher and Dr. Robert Verb
Helpful Algal Identification Guides
While most identification guides are designated for the professional, there are some useful
introductory guides available.
Freshwater Algae in Australia: A Guide to Conspicuous Genera (great color photographs, but
difficult to find in the United States).
Common Freshwater Algae of the United States: An Illustrated Key to the Genera (Excluding the
Diatoms) Gary E. Dillard (Author)
How to Know the Freshwater Algae - Spiral-bound (May 1, 1978) by G. Prescott, John Bamrick,
Edward Cawley, and Wm. Jaques
© 2010, Ohio Northern University: Dr. Kenneth Reid, Dr. Debra Gallagher and Dr. Robert Verb