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Sponges Cnidarians Ctenophores

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Presentation on theme: "Sponges Cnidarians Ctenophores"— Presentation transcript:

1 Sponges Cnidarians Ctenophores
Parazoa and Radiata Sponges Cnidarians Ctenophores

2 Phylum Porifera: The Sponges

3 General Information Mainly marine organisms; evolved from choanoflagellates May have algae or bacteria that give them color Larva are flagellated, adults considered sessile Many disease-fighting compounds holdfast

4 Tube Sponges Encrusting Sponges

5 Characteristics Can reproduce sexually or asexually
Gas exchange and excretion - diffusion at individual cells Supported by skeletal fibers: spicules or spongin Simple animals made of few specialized cells; NO tissues Asymmetrical Body with ostia Most are filter feeders / suspension feeders 1 family is carnivorous

6 Anatomy of a Sponge: Osculum Spongocoel Choanocyte Amoebocyte Mesohyl

7 Suspension Feeding & Gas Exchange

8 Sponge Reproduction: Asexual reproduction
Buds or gemmules Sexually – most sponges are hermaphrodites Cells become egg/sperm Sperm released into water Fertilization occurs in mesohyl (egg) Zygote becomes flagellated larva that leaves in flow of water

9 Phylum Cnidaria Jellyfish Box jelly Sea anemone Coral

10 Main Characteristics Diploblastic, radial symmetry
Cnidocytes with nematocysts concentrated in tentacles Gastrovascular cavity with 1 opening 2 layers separated by mesoglea Gas exchange and excretion occur by diffusion

11 Discharging of Nematocysts

12 Structure cont… Nerve nets Contractile cells
Connect sensory cells to contractile cells Sense organs around edge of body Ex. photoreceptors Contractile cells Not true muscles Act as hydrostatic skeleton

13 Cnidarians come in 2 forms:
Medusa – tentacles down Polyp – tentacles up Many alternate between medusa and polyp during life cycle

14 4 Classes of Cnidaria Hydrozoa Scyphozoa Cuboza Anthozoa

15 Cnidarians are Carnivores
Feed on fish, larva, comb jellies, other zooplankton Sting prey with their tentacles Mouth  gastrovascular cavity  mouth Jellyfish.asf

16 A word about corals: Many have symbiotic zooxanthellae
Environmental issue: Coral Bleaching

17 Portuguese Man-of-War
Interesting Facts… Portuguese Man-of-War Colonial Has sail-like float Tentacles can grow up to 165 feet and are nearly invisible

18 More interesting facts…
Box Jellies More toxic than Man-of-War Stings can lead to heart failure within minutes Tentacles may reach 15 feet

Diploblastic??; Biradial Symmetry Swim with 8 rows of ciliary combs Have 2 long tentacles with sticky cells Colloblasts Eat large amounts of fish larva & plankton Mouth + 2 anal pores Introduced/Invasive species (Black Sea)

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