Introduction to the Invertebrates

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Introduction to the Invertebrates
Lecture One Chapters 1 2
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What is an Invertebrate?

• I. Invertebrates are animals that do not possess
  a backbone.
• Additionally,
• Internal skeleton is not unique to vertebrates.
  (Starfish have an internal skeletons)
• Vertebrate animals have a brain encased in a bony
  skull (craniates).
• Nervous system of true invertebrates are
  different from true vertebrates.

VS.
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Why study the Invertebrates?

• II. The majority of all animals are
  invertebrates.
• 33/34 animal phyla are comprised entirely of
  animals without backbones. all vertebrates (
  5 of animals) belong in one subphylum
  (Vertebrata) within Ph. Chordata
• 85 of described animals (gt 1,097,289) are
  arthropods, and gt 350,000 are beetles.
• 1,000,000 species of insects, making them the
  most successful group of animals on earth.
• 7 of described animals (gt 93,195) are molluscs

Ph. Arthropoda
Ph. Mollusca
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The Six Kingdoms of Life

• The Prokaryotes Organisms lacking
  membrane-enclosed organelles and a nucleus and
  without linear chromosomes
• Kingdom Eubacteria ( true bacteria,
  Cyanobacteria spirochaetes)Kingdom Archaea
  (anaerobic or aerobic, methane producing
  microorganisms)
• The Eukaryotes organisms that do possess
  membrane-bound organelles and a nucleus and
  linear chromosomes
• Kingdom Fungi (molds, mushrooms, yeasts,
  etc.)Kingdom Plantae (multicellular plants)
• Kingdom Protista ( Protozoa) (single-celled
  microorganisms certain algae)
• Kingdom Animalia ( Metazoa) (multicellular
  organisms)

retz
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The Six Kingdoms of Life

• The Prokaryotes Organisms lacking
  membrane-enclosed organelles and a nucleus and
  without linear chromosomes
• Kingdom Eubacteria Kingdom Archaea
• The Eukaryotes organisms that do possess
  membrane-bound organelles and a nucleus and
  linear chromosomes
• Kingdom Fungi Kingdom Plantae
• Kingdom Protista ( Protozoa) 18/18 phyla
• Kingdom Animalia ( Metazoa) 34/34

The Invertebrates include
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Why study the Invertebrates?

• I. The majority of all animals are invertebrates.

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• The evaluation of present-day success of animal
  groups also involves consideration of the history
  of modern lineages, the diversity of life over
  time ( of species and higher taxa), and the
  abundance of life ( of individuals).

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Why study the Invertebrates?

• III. The invertebrates have been around a LONG
  time.
• Earth 4.6 billion years old
• Precambrian Period 2,500-570 mya
• 1st traces/evidence of eukaryotes algae, 3.0-2.0
  bya
• 1st positive traces of eukaryote fossils
  phytoplankton, 1.7-1.4 bya.

Kingdom Protista
Green algae Ph. Chlorophyta
extant examples
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Why study the Invertebrates?

• III. The invertebrates have been around a LONG
  time.
• Precambrian Period 2,500-570 mya
• First metazoa (700 mya) soft-bodied sea
  dwelling suspension detritus feeders
• Ediacaran Epoch (570-580 mya) - 1st evidence of
  many modern possibly extinct phyla. 1st
  Porifera, Cnidaria, Onychophora, Echinodermata,
  Arthropoda, etc.

Kingdom Animalia
Ph. Cnidaria
Ph. Annelida (?)
Ph. Arthropoda
preserved as shallow-water impressions on
sandstone beds
Fig 1.2
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Why study the Invertebrates?

• III. The invertebrates have been around a LONG
  time.
• Paleozoic Era 570-250 mya
• Lower Cambrian (530 mya) - Chengjiang deposits
  (southern China) the oldest well-preserved
  soft-bodied and hard-bodied fossils
• First Trilobites, Crustacea, Foraminifera and
  Agnathan fishes
• All tropic levels represented including giant
  predatory arthropods

Ch. 15
Ch. 5
Trilobites (extinct)Ph. Arthropoda
Foraminifera (extant ex.) Ph. Granuloreticulosa
The appearance of calcareous body skeletons in
the lower Cambrian was a fundamentally important
event in the history of life.
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• Lower Cambrian (530 mya) - Chengjiang deposits
  (southern China) the oldest well-preserved
  soft-bodied and hard-bodied fossils

Formation near Chengjiang, Yunnan Province
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Why study the Invertebrates?

• III. The invertebrates have been around a LONG
  time.
• Paleozoic Era 570-250 mya
• Middle Cambrian (520 mya) - Burgess shale Fauna
  (western Canada) included the 1st positive
  annelid tardigrade fossils.

Fig 1.3
Fig 1.3
Fig 1.3
OpabiniaPh. Arthropoda
AnomalocarisPh. Arthropoda
Ph. unknown
Charles Doolittle Walcott (1850-1927) an
invertebrate paleontologist, found the first
fossil specimen at Burgess Shale in 1909.
Ch. 15
Ch. 15
water Bear Ph. Tardigrada
Hallucigenia Ph. Onycophora
extant examples
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Why study the Invertebrates?

• III. The invertebrates have been around a LONG
  time.
• Paleozoic Era 570-250 mya
• Upper Cambrian (510 mya) Orsten deposits
  (southern Sweden) include 1st pentastomatid
  Crustacea and 1st primitive vertebrates.

Pentastomatid parasite fossils collected in 2004
in Västergötland, Sweden.
http//www.core-orsten-research.de/07_runningproje
cts.html
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Why study the Invertebrates?

• III. The invertebrates have been around a LONG
  time.
• Paleozoic Era 570-250 mya
• Silurian (415 mya) - First land animals
  (Arachnids, centipedes, millipedes)

Janovy
Centipede Cl. ChilopodaPh. Arthropoda

Janovy
Cl. Chelicerata Ph. Arthropoda
Millipedes Cl. DiplopodaPh. Arthropoda
extant examples
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Why study the Invertebrates?

• III. The invertebrates have been around a LONG
  time.
• Paleozoic Era 570-250 mya
• Lower Carboniferous period (302 mya) insects
  develop flight
• Permian period (270 mya) Pangaea supercontinent
• Mesozoic Era 250-65 mya
• Triassic period (250 mya) 1st modern coral
  reefs, 1st Diptera, and Pangaea begins to break
  apart.
• Jurassic period (130 mya) 1st flowering plants
• Cretaceous period (145 mya) ruling reptiles
  (incl. dinosaurs)

Tree fern galls in fossil record of the
Carboniferous period were evidence of the
beginning of a long history of insect/plant
coevolution.
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Why study the Invertebrates?

• III. The invertebrates have been around a LONG
  time.
• Cenozoic Era 65 mya - present
• Worldwide Cooling trend, movement of
  continents/plates to current positions.

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Why study the Invertebrates?

• IV. The invertebrates occupy a wide range of
  habitats
• Marine Habitats
• salt water covers 71 of earths surface
• life almost certainly evolved in the sea
• major events in invertebrate diversification
  occurred in the seas
• few lineages escaped the marine habitat
• Characteristics
• Stable temperature
• Stable salinity high water density ? enhanced
  invert. buoyancy
• Stable pH
• Abundance of CO2 , nutrients and sunlight ? high
  levels of photosynthesis in shallow and
  nearshore waters
• Ease in support, dispersal of gametes, waste
  dilution, and acquisition of dissolved materials

H. Knipes
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Why study the Invertebrates?

• IV. The invertebrates occupy a wide range of
  habitats.
• Estuaries and Coastal Marshlands
• halophyte organic matter forms the base of major
  detritus food web
• inverts adapt(ed) by migrating to more favorable
  environments or tolerating/accommodating to
  changing conditions
• Characteristics
• interaction of fresh and salt water
• Moving water tidal influences
• drastic seasonal changes
• dense halophyte stands nutrient-rich runoff
  from freshwater sources high productivity
• human caused pollution dredging, filling, storm
  drainage, thermal pollution from power plants,
  siltation from deforestation.

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Why study the Invertebrates?

• IV. The invertebrates occupy a wide range of
  habitats
• Freshwater Habitats
• smaller than oceans ? more easily influenced by
  environment ? relatively unstable
• inverts adapted to changing water availability
  through diapause stages
• far less biological diversity than oceans
• Characteristics
• extreme seasonal changes in temperature(complete
  freezing/drying)
• unstable salinity ionic/osmotic stress
• unstable pH
• rapid nutrient input and depletion

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Why study the Invertebrates?

• IV. The invertebrates occupy a wide range of
  habitats
• Terrestrial Habitats
• life on land is in many ways more rigorous than
  life in freshwater
• relatively few higher taxa successfully invaded
  the terrestrial world
• Characteristics
• temperature extremes encountered daily
• water balance is critical
• physical support of body requires energy
• Alternative mode for dispersing gametes,
  obtaining materials diluting waste

H. Knipes
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Why study the Invertebrates?

• IV. The invertebrates occupy a wide range of
  habitats
• Symbiosis
• inverts in intimate association with other
  animals plants
• at least half the planets species are symbionts
  all species have symbiotic partnerships
• Characteristics
• Parasitism (obligate or temporary) parasite
  benefits at hosts expense. Evolved in nearly
  every invert phylum.
• Mutualism (obligate or loose association)
  both host and symbiont benefit.
• Commensalism advantageous to one (the symbiont)
  but leaves the other (the host) unaffected. No
  obvious significant harm or mutual benefit

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Why study the Invertebrates?

• IV. The invertebrates occupy a wide range of
  habitats
• Symbiosis

Termite gut flagellates (symbionts)
Crustacean (parasite) ona fish (host)
http//www.workingnet.com/
http//img.photobucket.com/
http//www.ecuador-travel.net/
Clown fish and anemone (symbionts)
Cattle egret and cattle (commensalism)
Goldenrod (host) and a gall fly (parasite)
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Approach to studying the Invertebrates

• V. As Invertebrate Zoologists we are comparative
  biologists.
• We will deal with
• descriptions of organisms, particularly
  similarities and differences in characteristics
• the phylogenetic history of the organisms through
  time and
• the distributional history of organisms in space.

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Approach to studying the Invertebrates

• V. As Invertebrate Zoologists we are comparative
  biologists.
• Biological Classification consists of analyzing
  patterns in the distribution of characters among
  organisms, in order to group organisms.
• Similarity of characteristics shared among
  organisms, is used to measure biological
  relatedness among taxa.
• Biological nomenclature refers to a system of
  naming organisms in which (1) any single kind of
  organisms has one and only one correct name, and
  (2) in which no two organisms bear the same name.

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Approach to studying the Invertebrates

• V. As Invertebrate Zoologists we are comparative
  biologists.
• International Code of Zoological Nomenclature
  (I.C.Z.N.) established, on January 1, 1758, a
  revised set of rules for naming organisms that
  follow hierarchical categories based on the
  evolutionary relatedness of organisms.
• Category Taxon Kingdom Animalia
• Phylum Echinodermata
• Class Asteroidea
• Order Forcipulatida
• Family Asteriidae
• Genus Pisaster
• Species Pisaster giganteus (Stimpson,
  1857)
• Stimpson first described and named the organism
  in 1857.
• The parentheses indicate that this species is now
  placed in a different genus than originally
  assigned by Stimpson.

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Take-home Messages

• I. Invertebrates are animals that do not possess
  a backbone.
• II. The majority of all animals are
  invertebrates.
• III. The invertebrates have been around a LONG
  time.
• IV. The invertebrates occupy a wide range of
  habitats
• V. As Invertebrate Zoologists we are comparative
  biologists.

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Study Questions -

• I will give you questions at the end of each
  lecture. Each Friday I will select
• five questions from the lectures for the quiz. Be
  prepared to answer the
• questions using one or two complete sentences,
  each of which should
• contain two facts or ideas.
• What single, fundamentally important event took
  place at the beginning of the Cambrian, and what
  changes arose as a result?
• Give an approximate timeline and argue the
  significance of the four most important
  evolutionary events in the history of Metazoa.
• Explain the significance of tree fern galls in
  the Carboniferous.
• Define an obligate symbiotic relationships and
  give an example.

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Vocabulary -

• Metazoa
• Burgess Shale
• Symbiosis
• Parasitism
• Mutualism
• Commensalism
• I.C.Z.N.
• Similarity