Classification of Organisms
Lecture 6
Honors and General Marine Biology
What is Taxonomy?
Taxonomy – The science of naming and classifying
organisms.
Based on the works of
Carrolus Linnaeus (1735).
Binomial Nomenclature –
All species are assigned a
two part name.
The two names are genus
and species.
These represent Taxons, or
levels of classification.
Genus and species
What is the scientific name of human beings?
Species
Genus
Capitol
Lower Case
Why is it written this way?
- foreign language. Latin or Greek.
Written in
Italics or
underlined.
Taxonomic Hierarchy
What are the other taxonomic levels?
Broadest 
Kingdom
Phylum
Class
Order
Family
Genus
Species  Most Specific
Classification Systems
Classification systems are human inventions, so ….
-Based on our objectives, not always nature.
-Can (and are) constantly changed/updated.
Kingdom Systems
Traditional 5 Kingdom
Monera
Protista
Fungi
Plantae
Animalia
Modern 6 Kingdom
Archaebacteria
Eubacteria
Protista
Fungi
Plantae
Animalia
Marine Biology*
Monera
Protista
Fungi
Metaphyta
Metazoa
* Pinet (2000)
The
Tree
of
Life
The course will
go into more
detail, this is an
overview.
Kingdom Monera (Bacteria)
General Characteristics:
1) Microscopic
2) Unicellular
3) No Membrane bound Nucleus
(Prokaryote)
Importance:
1) Major Decomposer in
ecosystems.
2) Recycle organic mater into
useable forms for life.
3) Synthesize organic compounds
dissolved in seawater for other
organisms.
Monera (Blue-Green Algae)
Characteristics:
1) Same as Bacteria.
Spirulina sp.
2) Blue-green Algae are also
called blue-green bacteria.
Importance:
1) Photosynthesizers.
2) Nitrogen fixers.
3) Dominate stressed
environments.
Anabaena sp.
4) Likely the organism that is
responsible for oxygen
gasses building up in the
atmosphere.
Kingdom Protista
Includes: Foraminferans, Flagellates, Dinoflagellates and Diatoms.
Characteristics:
1) Single celled.
2) Eukaryotes.
3) Variable likeness.
Importance:
1) Large portion of total ocean biomass.
2) Critical ecologically:
a. Take up and release chemicals.
b. Make food.
c. Bottom Sediment
Kingdom Fungi
Characteristics:
1) Multicellular.
2) Eukaryotes.
3) Heterotrophs.
Importance:
1) Very common.
2) Help algae from drying out.
3) Decomposer and nutrient
recycling.
4) Few studies on marine
fungi have been done.
Marine Fungi - Endolithic
Kingdom Metaphyta
Includes: True plants and many of the macroalgae (Traditionally Protists).
Characteristics:
1) Multicellular.
2) Eukaryotes.
3) Autotrophs.
- Mangroove
- Seaweeds (Rockweed)
Importance:
1) Habitat.
Other Notes:
1) Confined to
continental shelf.
2) Photosynthesis.
- Eelgrass
Kingdom Metazoa
The Animals!
Characteristics:
1) Multicellular.
2) Hetertrophs.
3) Eukaryotes.
4) No Cell Walls.
Examples:
Sponges, clams,
oysters, squid, fish,
sharks, whales,
seals, gulls, etc…
Other Classifications (by Lifestyle)
1) Plankton –
The ocean drifters. Can not
swim against the current.
Types of Plankton:
a. Phytoplankton –
Plant like,
photosynthesize.
b. Zooplankton –
Animal like, do
not
photosynthesize.
By Lifestyle - continued
2) Neckton
The active swimmers.
Include fish, squid,
sharks, and whales.
- Sperm whale
By Lifestyle - continued
3) Benthos
Those that live on or in the
ocean bottom.
3 Types:
a) Epifuana – Animals on
the sea floor.
b) Infuana – Animals in the
sea floor.
c) Epiflora – Plants on the
sea floor.
Identifying Organisms
Dichotomous Keys – A tool
used by biologists in
order to identify an
unknown organism.
-They are constructed using
physical characteristics of an
organism.
-Use two parts statements, of
contrasting traits, to lead you
to the identity of the organism.
Bristles
Lobes
- How
many?
For Example
Example of a Dichotomous Key
Example of a diagnostic dichotomous key for some eastern United States oaks
based on leaf characteristics
1. Leaves usually without teeth or lobes: 2
1. Leaves usually with teeth or lobes: 5
2. Leaves evergreen: 3
2. Leaves not evergreen: 4
3. Mature plant a large tree — Southern live oak Quercus virginiana
3. Mature plant a small shrub — Quercus minima
4. Leaf narrow, about 4-6 times as long as broad — Willow oak
Quercus phellos
4. Leaf broad, about 2-3 times as long as broad — Shingle oak
Quercus imbricaria
5. Lobes or teeth bristle-tipped: 6
5. Lobes or teeth rounded or blunt-pointed, no bristles: 7
6. Leaves mostly with 3 lobes — Blackjack oak Quercus marilandica
6. Leaves mostly with 7-9 lobes — Northern red oak Quercus rubra
7. Leaves with 5-9 deep lobes — White oak Quercus alba
7. Leaves with 21-27 shallow lobes — Swamp chestnut oak Quercus
prinus
Your Turn
Use the provided materials to
identify the unknown organisms.
Answer the questions that follow.