Animal Diversity BSC 2011L

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Animal DiversityBSC 2011L
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Major Divisions of Life
Eukaryotes
Bacteria
Archaea
Microsporidia
Flagellata
Animalia
Fungi
Ciliata
Plantae
membrane bound nucleus
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Major Divisions of Life
Bacteria
Archaea
Microsporidia
Flagellata
Animalia
Fungi
Ciliata
Plantae
Multicellular
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Major Divisions of Life
These multicellular groups were divided based on
feeding mode fundamental organizational
differences.
Animalia
Fungi
Plantae

• heterotrophic
• (ingest and digest food)
• no cell walls

• heterotrophic
• (absorb food)
• cell walls made of chitin

• autotrophic
• (photosynthesis)
• cell walls made of cellulose

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Diversity of Animal Life
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What is an animal?

• multicellular (Branch Metazoa)
• eukaryote
• heterotrophic
• blastula stage
• generally motile

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How are these animals grouped?

• Complexity
• level of organization
• Morphology
• general body plan
• symmetry
• comparative biochemistry
• Development
• type of developmental patterns

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Level of Organization
Cell

• no tissues, no organs
• individual cells accomplish physiological
  functions

Tissue

• cells are organized into tissues and work
  together to accomplish physiological functions

Organ

• tissues are organized into organs that
  accomplish physiological functions

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General Body Plan

• presence of different body structures
• does it have a head?
• does it have a backbone?
• does it have tentacles? etc
• solutions to different body functions
• how do they move?
• how do they feed?
• how do they reproduce? etc

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Types of Symmetry

• the arrangement of body structures relative to
  some axis of the body

Asymmetrical
Bilaterial
Radial
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Comparative Biochemistry

• comparing DNA and amino acid sequences among
  animals

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Developmental Patterns

• type of cell cleavage
• type of embryo development
• presence, type, and formation of a body cavity
• etc

sea urchin
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Taxonomic Hierarchy
Linnaen system of binomial nomenclature

• example - Humans
• Kingdom Animalia
• Phylum Chordata
• Class Mammalia
• Order Primates
• Family Hominidae
• Genus Homo
• Species sapiens

the plural of Phylum Phyla
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Phylum Porifera

• the sponges

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Phylum Porifera
Branch Parazoa beside animal Sponges are
at the cellular level of organization and have no
tissues or organs. Sponges are assemblages of
cells embedded in a protein matrix and supported
by a skeleton of needle-like structures.
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External Morphology
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General Body Plan
osculum (pluraloscula)
spongocoel
ostia (singularostium)
water
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3 Body Types
Based on the complexity of the water canals

• Asconoid
• Syconoid
• Leuconoid

Increasing size Increasing SAV
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Asconoid Body Type
osculum
spongocoel
ostium
spongocoel is lined with choanocytes
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Asconoid Body Type
osculum
spongocoel
water
ostium
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Syconoid Body Type
radial canals are lined with choanocytes
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Syconoid Body Type
water
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Leuconoid Body Type
osculum
spongocoel
apopyle
ostium
incurrent canal
flagellated chambers
prosopyle
flagellated chambers are lined with choanocytes

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Leuconoid Body Type
osculum
spongocoel
water
apopyle
ostium
incurrent canal
flagellated chambers
prosopyle
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Microscopic Morphology
archaeocyte (amoebocyte)
porocyte
choanocyte
pinacocyte
mesohyl
spicules
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Skeletal Elements

• Mesohyl
• proteinaceous matrix that contains skeletal
  material and certain cell types
• equivalent to the connective tissue in other
  organisms
• made of collagen
• and spongin

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Skeletal Elements

• Spicules
• made of calcium carbonate or silica
• often used in taxonomic identification

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Cell Types

• Choanocytes
• collar cells
• diagnostic of phylum Porifera
• consist of a long flagellum surrounded by a
  collar of microvilli
• functions
• obtaining food
• creating water currents
• reproduction

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Cell Types

• Archaeocytes
• also called amoebocytes
• found throughout mesohyl
• totipotent ? can differentiate into any other
  type of cell
• functions
• digestion through phagocytosis
• make spicules
• reproduction

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Cell Types

• Pinacocytes
• line the exterior surface of the sponge
• functions
• some can regulate water flow by moving
  (open/close ostia)

outside of sponge
inside of sponge
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Cell Types

• Porocytes
• found in asconoid sponges
• form tubes in the body wall where water can pass
  through
• functions
• allow water flow

outside of sponge
inside of sponge
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Physiology

• Feeding
• Sessile filter-feeders
• Digestion
• Intracellular
• Gas exchange
• Simple diffusion
• Excretion (nitrogenous waste removal)
• Simple diffusion

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Physiology

• Reproduction
• Asexual
• fragmentation
• budding
• regeneration
• gemmules
• - in freshwater sponges only
• - resistant mass of archaeocytes that are
  produced in unfavorable conditions
• - when the environment is nice again, they
  will develop into sponges

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Physiology

• Reproduction
• Sexual
• usually monoecious
• (a single individual can produce both male and
  female gametes both sexes are within one
  individual)
• sperm are released into the water and eggs are
  retained within the sponge
• motile larvae are produced (some swim, some
  crawl), metamorphose, and become juvenile sponges

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Ecology

• most sponges are marine (5000 species) but there
  are 150 freshwater sponge species
• Sponges are found at all depths but certain
  species are restricted to particular depths due
  to how their spicules are formed
• There are few sponge predators because they
  usually contain distasteful toxins
• Some predators (e.g. sea slugs) sequester these
  sponge toxins which in turn deters their own
  predators

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Ecology

• Symbiosis
• the living together of 2 different species in an
  intimate relationship
• Types of symbiotic relationships
• Mutualism both partners benefit
• Commensalism 1 partner benefits, 1 partner is
  unaffected
• Parasitism 1 partner benefits, 1 partner is
  harmed
• There are examples of all 3 of these types of
  symbiotic relationships occurring in Sponges

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Ecology

• Mutualism
• certain endosymbiotic bacteria and algae living
  within the sponge provide additional food for the
  sponge while the sponge provides a place for the
  bacteria and algae to grow

• some crabs will attach a piece of sponge to
  their body to use as camouflage and to deter
  predators while the sponge gets to move around

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Ecology

• Commensalism
• many different species live within sponges and
  receive food and shelter benefits but do nothing
  for the sponge
• e.g. 15cm² piece of sponge in California was
  found to house 100 different species of plants
  animals
• e.g.Venuss Flower basket
• a pair of shrimp live their entire lives
• within 1 sponge

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Ecology

• Parasitism
• boring sponges are parasites on certain corals
  because they bore into the calcium carbonate
  base of the coral for protection and kill part of
  the coral in the process

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Current Sponge Research

• Chemical defenses
• the compounds that sponges use to defend
  themselves from predators are being researched
  for potential biomedical applications
• Cell-cell communication
• although sponges have no nervous system, cells
  are capable of communicating with one another
• Sponges can also recognize foreign cells and
  particles and mount an immune response
• Animal Evolution
• relationship between sponges and all other
  Metazoans remains unclear