1. Come in, and QUIETLY have a seat.2. Study Unit 1 Vocab-

Quiz will be given in 5 minutes!3. Once you Finish Quiz-bring folder and paper to front.4. Get ready to take notes on Phylum Porifera!

Invertebrates Part 1 Animal Characteristics Sponges and Cnidarians

April Adams

Zoology

Zoology StandardsSZ2. 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

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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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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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)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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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 move• 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:• Circulation: none• Respiration: oxygen diffuses into body from

water• 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

Groups & Uses of Cnidarians• 3 Groups of Cnidarians:

1.Hydrozoans: medusa and polyp colonies which

appear to be one organism-different types of polyps

work together to serve the entire colony

Ex: Hydra, portuguese-man-of-war, fire coral

2. Scyphozoans: independent medusa forms

Ex: jellyfish, box jelly, medusa

3. Anthozoans: all marine -polyps only, medusa absent

Ex: corals, sea anemoneRiches of the sea

Video jewel anenome