Sponges and Cnidarians Chapter 12 Section 2 Introduction to Animals Student Composed Notes.
Animal Characteristics Sponges and Cnidarians Zoology.
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Transcript of Animal Characteristics Sponges and Cnidarians Zoology.
Animal Characteristics Sponges and Cnidarians
Zoology
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
Planes ofsymmetry
Radial
Planes of Symmetry
Dorsal
Ventral
Anterior end
Posterior endBilateral Symmetry
2. Body arrangements:
a. anterior: head regionb. posterior: tail regionc. dorsal: back or topd. 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
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
SPONGES
Section 26-2
Water flow
Choanocyte
Spicule
Pore cell
Pore
Epidermal cell
Archaeocyte
Osculum
Central cavity
Pores
The Anatomy of a Sponge
• 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
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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Simple Sponge Morphology
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)
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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Sponge Body Forms
Classes• Calcarea- spicule
made of calcium carbonate-
• Hexactinellida- glass sponge (spicule-silicon)
• Demospongia- “people’s sponge”, spicules are spongin (ex. Bath)
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Class CalcareaGrantia
• 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 ReproductionAsexually:• Fragments break off and grow into
new individuals• Buds form from sides of parent
sponge, break offnew sponge• can grow back missing parts
(regeneration)• Gemmules: During droughts or cold
weather, some freshwater sponges produce internal buds called gemmules. A food-filled ball of amebocytes surrounded by a protective coat made of organic material and spicules
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
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PoriferaPorifera PlatyhelmithesPlatyhelmithes MolluscaMollusca ArthropodaArthropoda
HemichordataHemichordataCnidariaCnidaria NemerteaNemertea AnnelidaAnnelida
EchinodermataEchinodermataChordataChordataLophophoresLophophores
ProtozoansProtozoansPrecambrian
Before 670 MYA
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. provide the skeleton of a sponge?
b. Filter food out of the water?
c. Allows water to exit the sponge?
d. Class Hexactinellida has spicules made of?
4. How do sponges survive without body systems? (Be specific)
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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Hypothesis of Multicellularity
Cnidarians• Phylum Cnidaria: “stinging cell”• Hollow gut- (coel)• radial symmetry• Germ Layers: 2
epidermalgastrodermal
• 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
• 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
Label the hydra on your notes!
http://www.arkive.org/common-jellyfish/aurelia-aurita/video-10.html
Without Body Systems, how do they survive?
• Nervous: Cephalization absent; Nerve Net-conducts 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 zygotelarvaadult)
• 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: Body Forms
• Polyp: body with tentacles hanging upward
• Ex: hydra, sea anemone
• video polyp predation
• Medusa: body with tentacles hanging downward
• Ex: jellyfish
basal disc: sticky structure at the bottom of polyp ; sessile
Epidermis
Mesoglea
Gastroderm
Mesoglea
Gastrovascular cavity
Mouth/anus
Tentacles
Tentacles
Mouth/anus
Gastrovascularcavity
Polyp
Medusa
Structure:The Polyp and Medusa Stages
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Diploblastic - 2 germ layers
– Epidermis - outer covering (ectoderm)– Mesoglea - middle non-living jelly-like layer– gastrovascular cavity (endoderm)
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 anemoneRiches of the sea
Video jewel anenome
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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 AnthozoaSea Anemone
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Class AnthozoaMetridiumClass AnthozoaMetridium
MouthMouthMouthMouth
TentaclesTentaclesTentaclesTentacles
PharynxPharynxPharynxPharynx
SeptumSeptumSeptumSeptum
Gastrovascular cavityGastrovascular cavityGastrovascular cavityGastrovascular cavity
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Symbiosis
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Class AnthozoaCorals
• Protective skeleton of calcium carbonate
• Polyp retracts when not feeding
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CoralsColony of interconnected polyps
CoralsColony of interconnected polyps
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Class AnthozoaMeandrinaBrain Coral
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Class AnthozoaGorgoniaSea Fan
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Class AnthozoaTubiporaPipe Organ Coral
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Class AnthozoaActinodiscusMushroom Coral
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Class AnthozoaAcroporaStaghorn 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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Coral Reef Ecosystem
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Photo © McGraw-Hill Higher Education, Barry Barker, Photographer
Coral Reefs
• 200 C or warmer water; large formations of calcium carbonate laid down by organisms over thousands of years
1. Fringing Reef
• Less than a quarter of a mile from shore
2. Barrier Reef
• Runs parallel to shore, has a wider and deeper lagoon
3. Atoll Reef
• Reef that circles a lagoon of water rather than an island
Here they are together…
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AnthozoaScyphozoa Cubozoa
Hydrozoa
Radial symmetry, cnidocytes, planula larva
Septa divide gastrovascular cavity
Medusa cuboidal
Polyp stage reducedLoss of medusa
Cladogram of Cnidaria
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The End
Phylum Ctenophora• Characteristics• All marine • Includes comb jellies • Have eight rows of fused cilia called "comb rows" • Largest animal to move by cilia • Move by beating cilia • Lack cnidocytes but have cells sticky cells called
colloblasts that bind to prey • Colloblasts located on two ribbon-like tentacles • Have sensory structure called apical organ to detect
direction in the water • Most are hermaphrodites (make eggs & sperm) • Produce light by bioluminescence
Comb jellies