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Sponges and Cnidarians

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1 Sponges and Cnidarians
Life Science

2 Review the Animal Kingdom
4 Major Characteristics? Multicellular Eukaryotic Heterotrophs Cells lack cell walls

3 7 Essential Functions? Feeding Respiration Circulation Excretion
Response Movement Reproduction

4 Hard Shells Fur & Milk Glands Amniotic Egg Lungs Bony Skeleton jaws Brain Encased Skull



7 Phylum Porifera “Pore-Bearers”

8 Sponges are the simplest of all animals.
They are multicellular, heterotrophic, have no cell walls, and have specialized cells.

9 Sheet sponge Carnivorous- eat small crustaceans

10 Adult sponges are sessile.
CAN”T MOVE They live attached to a single spot.

11 Sponges are asymmetrical filter feeders
Feed on : bacteria, unicellular algae, and protists through filter feeding.

12 IV. Phylum- Porifera (“pore bear”) –sponges – simplest of all animals
A. Body Plan – asymmetrical, pores all over body with large hole on top called osculum where water is pumped through, Have no mouth or gut, Have no tissues or organ systems, Simple functions are carried out by a few specialized cells B. Protection: skeleton of spicules (glass-like material) or spongin (soft)

13 Asymmetrical? Have no front or back ends, no left and right sides
A large, cylindrical water pump The body forms a wall around a large central cavity through which water flows continually

14 Protection- Silica (cells of glass offer protection and support

15 C. Feeding – filter feeders, trap microorganisms in water flow.
1. Collar cells - specialized cells that use flagella to move a steady current of water thru the sponge. Each collar cell digests its own food. 2. Archaeocytes - specialized cells that make spicules 3. Pore cells – Cells thru which water flows into the body of a sponge

16 Major Body Functions D. Respiration/ Circulation/ Excretion – water flow carries out all body functions (osmosis and diffusion) As water moves through the cavity: Oxygen dissolved in the water diffuses into the surrounding cells 2. Carbon dioxide and other wastes, diffuse into the water and are carried away

17 Major Body Functions E. Response/Movement- no nervous system, do produce toxins, adults don’t move (sessile), larva swim F. Reproduction- sexually with internal fertilization between two different sponges or asexually by budding or fragmentation

18 Osculum A large hole at the top of the sponge, through which water exits The movement of water provides a simple mechanism for feeding, respiration, circulation and excretion

19 The Anatomy of a Sponge Water flow Osculum Collar Cell Central cavity
Pores Spicule Pore cell Pore Epidermal cell Archaeocyte

20 Ecology of Sponges Ideal habitats for marine animals such as snails, sea stars, sea cucumbers, and shrimp Mutually beneficial relationships with bacteria, algae and plant-like protists

21 Sponge Life Cycle (Sexual Reproduction) Sponges are hermaphrodites.
MEIOSIS Haploid (N) Diploid (2N) Adult sponge releases sperm into the water New sponge Sperm (N) Mature sponge (2N) Egg (N) Larva attaches to a hard surface Larva (2N) The zygote develops into a free swimming larva Sperm fertilize eggs inside the body of another sponge FERTILIZATION

22 Review Questions Answer the 4 questions on your own.


24 Asexual Reproduction-Budding
A new polyp genetically identical to the parent is formed.

25 Jelly fish

26 Lion’s Mane Jelly



29 Some have eyes! Box Jelly

30 Colony of polyps

31 Deadly within 3 minutes! Chironex fleckeri
Found off the coast of Australia Deadly within 3 minutes! Over 100 deaths in the last 25 years Chironex fleckeri

32 Anemones

33 Colonial Anemone


35 Coral Reefs

36 Brain Coral

37 Orange Cup Coral Red Sea Fan

38 Sea Pen Feathery Hydroid

39 Fungiid Coral- this coral can move!

40 Carpet Anemone

41 Giant Sea Fan Mushroom Coral

42 Solid Table Coral Staghorn Coral


44 Phylum Cnidaria –more complex than sponges
A. Carnivorous animals with stinging tentacles around their mouths B. Simplest animals to exhibit symmetry – cnidarians have radial symmetry C. Simplest animals to have true tissues including nerves

45 Cnidarians have two body forms
Polyp - stationary, vase-shaped Medusa - swimming, cup-shaped Examples: hydra, coral, sea anemone Examples: jellyfish, portuguese man of war

46 Examples: hydras, jellyfishes, sea anemones, and corals
A. Hydrozoans: Most of life as polyp ex. hydra B. Scyphozoans: Most of life as medusa  ex. jellyfish C. Anthozoans: Only polyp stage in the life cycle  ex. corals and sea anemones

47 Simplest animal with true tissues.
soft bodied, have tentacles, radial symmetry, 1. Gut – gastrovascular cavity with one opening 2. Nerve net- detects stimuli 3. Hydrostatic Skeleton- movement and support with the use of muscles

48 The Polyp and Medusa Stages
1. Polyp - Stationary, Examples: Hydra, Coral, and Sea Anemone 2. Medusa- Swimming, Cup Shaped. Examples: Jelly Fish and Man O War

49 The Polyp and Medusa Stages
3 tissue layers Epidermis Mesoglea Gastroderm Tentacles Mouth/anus Gut Bell gut Mouth/anus Tentacles Medusa Polyp

50 1. Feeding- kill small prey with stinging cells in tentacles, digest in gut, food in and waste out of one opening. 2. Respiration/Circulation/Excretion- all by diffusion (no true organs) 3. Response- have specialized sensory cells and nerve net to gather info and react to stimuli.

51 b. Ocelli: eyespots made of cells that detect light
Response a. Statocysts: groups of sensory cells that help determine the direction of gravity b. Ocelli: eyespots made of cells that detect light

52 (StingingStructure) (Stinging Cell)

53 4. Movement- propel themselves with water using hydrostatic skeleton
5. Reproduction- asexually by budding, sexually by external fertilization, sperm and egg are released and meet in water

54 IX. Ecology of Cnidarians
A. Source of new drugs/chemicals sunscreen 855 B. Provide habitats for marine organisms C. Source of food for other organisms (like sea turtles) D. Symbiotic relationships with other organisms

55 Jellyfish Life Cycle (Sexual Reproduction)
Female medusa (2N) MEIOSIS Fertilization occurs in the open water, producing many diploid zygotes. Egg (N) Adult medusas reproduce sexually by releasing gametes into the water. FERTILIZATION Sperm (N) Each zygote grows into a ciliated larva. The larva eventually attaches to a hard surface and develops into a polyp. Zygote (2N) Male medusa (2N) Young medusa Swimming larva Polyp The polyp buds to release young medusas. Haploid Diploid Budding polyp

56 Answer the 2 review questions

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