Transcript Unit 5: Animals – Sponges, Cnidarians, & Worms

1. Come in, and QUIETLY
have a seat.
2. Study Unit 1 VocabQuiz will be given in 5
minutes!
3. Once you Finish Quizbring folder and paper
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4. Get ready to take notes
on Phylum Porifera!
Invertebrates Part 1
Animal Characteristics
Sponges and Cnidarians
April Adams
Zoology
Zoology Standards
SZ2. Students will explain the evolutionary history of animals over the
geological history of Earth.
a. Outline the geological history of Earth and discuss the major environmental
changes that have occurred over time.
c. Describe the fossil record of the animals including discussing the Cambrian
Explosion and major extinction events.
SZ3. Students will compare form and function relationships within animal
groups (clades) and across key taxa.
a. Explain the similarities and differences among major body plans (e.g.,
asymmetry, radial and bilateral symmetry).
SZ4. Students will assess how animals interact with their environment
including key adaptations found within animal taxa.
a. Discuss morphological and physiological adaptations relative to ecological
roles.
b. Relate animal adaptations, including behaviors, to the ecological roles of
animals.
c. Explain various life cycles found among animals (e.g., polyp and medusa in
cnidarians;
Characteristics of Animals
1. Multicellular, eukaryotes
2. Heterotrophs
3. Cells w/out cell walls, many have specialized
functions
4. Usually have a method of movement
5. Most reproduce sexually
6. Require oxygen
Describe the Body Plans of Animals
1. Symmetry: balance in body proportions
a. Asymmetrical:have irregularly shaped
bodies, no symmetry
b. Radial symmetry: can be divided along any
plane to produce 2 halves which look alike
c. Bilateral: can be divided only one way to
produce mirror image halves
Radial
Bilateral Symmetry
Posterior end
Dorsal
Ventral
Planes of
symmetry
Anterior end
Planes of
Symmetry
2. Body arrangements:
a. anterior: head region
b. posterior: tail region
c. dorsal: back or top
d. ventral: abdomen or bottom
Sponges: Phylum Porifera
(“pore bearer”)
• Simplest of all animals
• Assymetrical
• Sessile filter-feeders
whose bodies have many
pores
• Obtain oxygen by filtering
water
• No nervous system or
organ systems
• No tissue organization
• Acoelomates
SPONGES
Digestion: NO SYSTEM filter feeders chooanocytes
Excretion: NO SYSTEM Basic diffusion; wastes exit
thru osculum
Circulation: NO SYSTEM- amoeboid cells
Respiration: NO SYS. diffusion-obtain oxygen from
water
Reproduction: ASEXUAL AND SEXUAL
The Anatomy of a Sponge
Section 26-2
Osculum
Water flow
Central cavity
Pores
Choanocyte
Spicule
Pore cell
Pore
Epidermal cell
Archaeocyte
• Outer epidermal layer
• jellylike middle layer ( amoeboid cells and spicules)
• Spongocoel- inner cavity lined with choanocytes
Sponge Body Structures
• A. Osculum: water exits-part of
feeding
• B. Pore cells (ostia): water
enters-part of feeding
• C. Collar cells:(choanocytes)line interior, have flagella to
filter food from water
• D. Amoebocytes: carry
nutrients from collar cells to
body of the sponge
• E. Spicules- support/skeleton
• F. Epithelial cells-”skin”support/protection
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Simple Sponge Morphology
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Three Body Types(Forms)
• Asconoid- simple- pore cells open directly into
sponge
• Syconoid- more complex- pore cells open into
canals
• Leuconoid- most complex- pore cells open into
canals that open into chamber (ex. Bath
sponge)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Sponge Body Forms
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Classes
• Calcarea- spicule
made of calcium
carbonate-
• Hexactinellida- glass
sponge (spicule-silicon)
• Demospongia“people’s sponge”,
spicules are spongin
(ex. Bath)
Class Calcarea
Grantia
• Small
• Vase shape
• Spicules of calcium
carbonate
– Straight or 3-4 rays
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Class Hexactinellida
Euplectella
• Spicules
– Siliceous
– 6 rays
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Class Demospongiae
Spongia
• Spicules
– Siliceous
– spongin
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Sponge Reproduction
Asexually:
• Fragments break off and grow into
new individuals
• Buds form from sides of parent
sponge, break offnew sponge
• can grow back missing parts
(regeneration)
Sexually:
• Hermaphrodites: produce both
eggs and sperm
• Gametes are released into water
(external fertilization)larva swim to
new area
Lifestyle and
Importance
• Aquatic- mostly marine
sessile as adults with free living larva
Importance- As filter feeders, they clean water
in ecosystem
Large sponges filter 1500 liters/day
Porifera Platyhelmithes Mollusca Arthropoda
Cnidaria
Nemertea
Annelida
Echinodermata Hemichordata
Lophophores Chordata
Precambrian
Protozoans
Before 670 MYA
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How much did your brain
“sponge” in?
1. What are the basic characteristics of
Animals?
2. What does the word Porifera mean?
3. What type of structure?
a.
b.
c.
d.
provide the skeleton of a sponge?
Filter food out of the water?
Allows water to exit the sponge?
Class Hexactinellida has spicules made of?
4. How do sponges survive without body
systems? (Be specific)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Hypothesis of Multicellularity
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Cnidarians
Phylum Cnidaria: “stinging cell”
Hollow gut- (coel)
radial symmetry
Germ Layers: 2
epidermal
gastrodermal
NO ORGAN SYSTEMS
Segmentation: none
Coelom: Acoelomate
Movement: sessile or motile
Have tentacles- stinging cells
found on tentacles
Structures:
• One body opening (mouth) for food
to enter and wastes to exit
• Gastrovascular cavity: interior
cavity where food is digested &
nutrients are circulated around the
body
Label the hydra on
your notes!
• Nerve net: net of nerves that allow
impulses to travel around the body,
senses the environment
• NEMATOCYSTS tentacles that
contain stinging cells(cnidocysts)
used to capture and poison prey
http://www.arkive.org/common-jellyfish/aurelia-aurita/video-10.html
Without Body Systems, how
do they survive?
• Nervous: Cephalization absent; Nerve Netconducts impulses
• Skeleton: Hydrostatic- water pressure
maintains shape
• Respiration: Oxygen diffuses into body from
water
• Digestion: one body opening for food &
wastes
• Excretion: none
• Circulation: none
• Reproduction: asexual and sexual,
alternation of generations
Cnidarian Reproduction
• Asexually: by budding
• Sexually: in medusa form
only, sperm and eggs are
released into water
(fertilized egg
zygotelarvaadult)
• Thousands of gametes are
released at a time
Alternation of Generations:
Video: medusa releasing from polyp
Answer the following:
Explain why sponges and
cnidarians release so many
gametes into the water
Cnidarians: • Polyp: body with tentacles
Body Forms hanging upward
• Ex: hydra, sea anemone
• video polyp predation
• Medusa: body with
tentacles hanging
downward
• Ex: jellyfish
Structure:The Polyp and Medusa
Stages
Epidermis
Mesoglea
Gastroderm
Tentacles
Mesoglea
Gastrovascular cavity
Mouth/anus
Mouth/anus
Gastrovascular
cavity
Tentacles
Medusa
Polyp
basal disc: sticky structure at the
bottom of polyp ; sessile
Diploblastic - 2 germ layers
– Epidermis - outer covering (ectoderm)
– Mesoglea - middle non-living jelly-like layer
– gastrovascular cavity (endoderm)
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Classes of Cnidarians
1. Hydrozoa:fresh water and marine, polyp and medusa
present ex. Hydra, man-o-war, Obelia
2. Scyphozoans: cup- large jellyfish ex. box
3. Anthozoans: flower -all marine -polyps only
Ex: corals, sea anemone
Riches of the sea
Video jewel
anenome
Class Hydrozoa
• Freshwater & marine.
• Medusa and polyp colonies
which appear to be one
organism-different types of
polyps work together to serve
the entire colony
• Ex: Hydra, Obelia, Gonionemus
Physalia (portuguese-man-of-war)
• Asexual repro.-budding.
• Sexual repro. via gametes
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Class Scyphozoa
• Scyph= “cup”
• Large- Tentacles up
to 70 meters in
length
• All marine
• Independent
medusa forms
• Lack polyp stage or
have for a very short
time
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Class Anthozoa
• ANTHO=“flower”
• All polyps-Medusa
stage absent
• Solitary or colonial
• Some produce
protective skeletons
• All Marine
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Class Anthozoa
Sea Anemone
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Class Anthozoa
Metridium
Tentacles
Mouth
Pharynx
Septum
Gastrovascular cavity
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Symbiosis
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Class Anthozoa
Corals
• Protective skeleton of
calcium carbonate
• Polyp retracts when
not feeding
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Corals
Colony of interconnected
polyps
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Class Anthozoa
Meandrina
Brain Coral
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Class Anthozoa
Gorgonia
Sea Fan
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Class Anthozoa
Tubipora
Pipe Organ Coral
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Class Anthozoa
Actinodiscus
Mushroom Coral
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Class Anthozoa
Acropora
Staghorn Coral
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Coral Reefs
• Formed over thousands of
years from successive layers
of coral skeleton deposits
(calcium carbonate forms
underwater mountains of coral
animal skeletons)
• The underwater equivalent of
the amazon jungle- very high
species diversity and biomass
• Reefs contain sponges,
colonial hydrozoans,
anemones, many varieties of
coral, fish, many types of
worms we’ve not discussed,
not to mention bryozoans,
ctenophores, protists,
bacteria, etc etc..
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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Coral Reef Ecosystem
Photo © McGraw-Hill Higher Education, Barry Barker, Photographer
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Cladogram of Cnidaria
Anthozoa
Scyphozoa
Hydrozoa
Cubozoa
Medusa cuboidal
Loss of medusa
Polyp stage reduced
Septa divide
gastrovascular cavity
Radial symmetry,
cnidocytes, planula larva
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The End
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