Taxonomy

I. TaxonomyA. Definition – the classification and

naming of living organismsB. Purpose – to help organize and

understand informationC. History

1. In the beginning, two groups classified

(a) Plants(b) Animals

2. In 400 B.C. Aristotle (a Greek philosopher)

(a) Was the first to classify animals into three groups

(1) Land dwellers

(2) Air dwellers

(3) Water dwellers

(b) Was the first to classify plants into three groups

(1) Short stem

(2) Medium stem

(3) Tall stem

(c) Too general and not very scientific

(d) Worked until the invention of the microscope

3. In the 1600’s, John Ray (naturalist)

(a) Used the term species – group of organisms structurally

similar and passes similarities on to offspring

(b) Used the term genus – closely related species; Ex.: Feline

4. Carolus Linnaeus – the father of taxonomy, established the modern day classification of organisms

D. Modern day classification

1.Domain

2. Kingdom – broadest category (6)

3. Phylum

4. Class

5. Order

6. Family

7. Genus

8. Species – the narrowest

(no two species are the same)

E. Naming of Organisms1. Nomenclature – system for

naming organisms(a) Linnaeus used John Ray’s

genus and species term to name organisms

(b) Each organism has a genus name and a single Latin species name

(c) Latin is a dead language so it will never change like English does

(d) inu – perro – dog – or to scientists: Canine

domesticus(e) No two species could be

described by the same Latin word

2. Binomial Nomenclature – a two-word system used to identify and name organisms

(a) This is an organism’s scientific name

(b) Ex.: Carcharodon carcharias

great white shark

(c) We know most animals by their common name

3. Scientific Name – must include both the genus and species names

(a) must be written as follows:

1st – the genus name is capitalized

2nd – the species name is lower-cased

3rd – both names must be underlined or written in italics

(b) Ex.: Delphinus delphis –

dolphin

Orcinus orca –

killer whale

Physalia physalis –

Portuguese man-o-war

(c) Scientific names are needed because not all common names are the same

II. The Five KingdomsA. Kingdom Monera

(Eubacteria and Archaebacteria)

1. Marine representatives – true bacteria

& cyanobacteria (Blue-green algae)

2. Characteristics of Monerans(a) Most primitive group of organisms

(b) Prokaryotes – no nucleus, lacks cell “stuff”

(c) Unicellular

(d) Asexual reproduction

(e) Oldest life form

3. Function

(a) Bacteria – converts “waste” into edible food; decomposers

(b) Cyanobacteria – photosynthetic; produces O2; (not a plant = its unicellular)

B. Kingdom Protista

1. Marine representatives:

(a) Unicellular algae – Ex. Diatom & Dinoflagellates

(b) Protozoa – unicellular animas; Ex. Copepods

2. Characteristics of Protists

(a) Eukaryotes (most microscopic) – has a nucleus; many organelles

(b) Unicellular

(c) Asexual or sexual reproduction

3. Function in marine ecosystem

(a) The start of the marine food chain

(b) 98% of the marine “plant” growth

(c) #1 producers of oxygen (not plants because Protista are unicellular)

(d) 1st to be affected by pollution

(e) Most go through photosynthesis

(f) Feed over half the marine pollution

C. Kingdom Fungi1. Marine representatives – lichens –

blackish or brownish “grassy” organisms2. Characteristics of Fungus

(a) Eukaryotes(b) Multi-cellular, but simple

(c) Reproduce by spores(d) Non-photosynthetic

3. Function(a) Decomposers – feed on dead

organisms’(b) Hiding place for some

organismsD. Kingdom Plantae

1. Marine representatives(a) Seaweed

(b) Multi-cellular algae(c) Flowering plants – Ex. sea

grasses, mangrove trees2. Characteristics of plants

(a) Eukaryotes(b) Multi-cellular & complex

(c) Photosynthesis3. Function

(a) Produces oxygen (small amount in marine ecosystem)

(b) Provides food for manatees, turtles, etc…

(c) Provides home for a variety of organisms

(d) Medicines

E. Kingdom Animalia

*Eukaryotes, multi-cellular & complex, most numerous

group

III. Kingdom PlantaeA. General Information

1. Multi-cellular2. Photosynthetic3. Divided into 2 major subkingdoms

(a) Subkingdom Thallophyta – “no seeds”includes “seaweeds” & “kelp”

(b) Subkingdom Tracheophyta – includes “flowering plants” & “grasses”

B. Subkingdom Thallophyta

1. General Information

(a) mostly attached to a firm substrate Ex. Rocks, reefs, etc

(b) shallow waters for photosynthesis

(c) sargassum seaweed is not attached, but free-floating(d) kelp grows several hundred feet(e) no true roots

2. Types of Thallophyta (3)(a) Division Chlorophyta

1) green algae2) clear green due to chlorophyll3) over 7,500 species (both

marine & freshwater)

4) “sponge weed” & “sea lettuce” most common

5) range from microscopic to 25 ft.

(b) Division Phaeophyta

1) brown algae

2) brown/golden in color

3) over 1,500 species (entirely marine)

4) most common phaeophyte – sargassum seaweed

5) largest phaeophyte – kelp (grows 100’s of ft.)

6) humans farm kelp7) Parts of a kelp

a) Holdfast – anchors kelp to bottom b) Stipe – stalk, supports kelp c) Blade – leaf like part of kelp d) Pneumatocyst – “floats” on the

blade*easily uprooted

pneumatocyst

stipe

blade

holdfast

http://www.oceanlight.com/spotlight.php?img=2411

(c) Division Rhodophyta

1) red algae

2) reddish pigment

3) over 4,000 species

4) more red algae than all algae combined

5) live mostly in warm waters

6) live in deep water (150 meters/450ft)

7) red light penetrates deeper than other lights

8) “coralline” algae secretes calcium carbonate to help “cement” coral reefs together

3. Importance

(a) food for marine animals

(b) home for marine animals

(c) farmed by humans for

1) food (ice cream)

2) agar – thickening agent; used in capsules & to

study bacteria

3) medicine

C. Subkingdom Tracheophyta (flowering plants)

1. General information

(a) very few marine species

(b) have seeds “flower” (Thallophytes do not have seeds)

(c) true rooted

2. Types of Tracheophytes (both types in division angiosperms)

(a) Grasses

1) found in shallow waters close to land

2) “surf grass”; “turtle grass”; “sea grass” & “manatee grass”

3) rooted into ground

(b) Mangrove trees

1) only in tropics & warm waters

2) totally marine adapted

3) very sturdy due to root growth

4) roots very complex – acts as an anchor & a “straw” to “suck” up water & nutrients

5) roots need aeration, so only grow in intertidal zone

6) home to many marine animals that live only among the mangrove roots

7) can with stand most storms, rarely uprooted

3. Importance(a) food for marine animals(b) provide cover for marine

animals(c) act as nursery

(d) act as a giant “filter system” (roots suck up nutrients & some pollution)

(e) keeps area from “suffocating” by sucking up nutrients

(f) grasses keep silt from “filtering” off land into ocean