Phylum Cnidaria Sea Anemones Jellyfish Corals 1 2

Phylum Cnidaria Sea Anemones, Jellyfish, & Corals 1

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I) Cnidarians A) Phylum Cnidaria 1) Means “to have stingers” B) C) D) E) True Tissues Radial Symmetry Radial Nerve Net Partial Digestive Tract 1) Only have one opening F) Some 10, 000 species known G) First appeared some 540 -650 Million Years 3 Ago

II) Morphology A) Oral surface 1) Where the mouth is B) Aboral Surface 1) Opposite side of the mouth C) Central mouth / anus surrounded by tentacles D) Mouth opens to gut 4

II) Morphology E) Nematocysts 1) Cnidae 2) Unique stinging structure 5

II) Morphology F) Polyp 1) Sac-like attached stage with mouth & tentacles orientated upwards G) Medusa 1) Jellyfish, an upside down polyp for swimming H) Some cnidarians go through both life stages, others only one 6

II) Morphology I) Epidermis 1) External cell layer J) Gastrodermis 1) Lines the gut K) Mesoglea 1) Middle, gelatinous layer 7

III) Feeding A) Practically all are carnivores B) Use nematocysts primarily to capture prey 1) Some contain toxins C) Ingest into mouth D) Extracellular digestion 1) Initial digestion that takes place outside the cells (in the gut) E) Intracellular digestion 1) Final digestion within cells lining the gut 8

IV) Reproduction 9

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V) Classes of Cnidarians A) Hydrozoans 1) Leathery or bushy colonies of polyps 2) Siphonphores: drifting colonies of polyps B) Scyphozoans 1) Jellyfish 2) Larger, bell-shaped medusas C) Cubozoans D) Anthozoans 1) Sea Anemones 2) Corals 11

A) Hydrozoans 12

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B) Scyphozoans 14

C) Cubozoans 15

D) Anthozoans 16

D) Anthozoans 17