Sea Anemones, Jellyfish, & Corals Phylum Cnidaria Sea Anemones, Jellyfish, & Corals

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

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

II) Morphology Nematocysts Cnidae Unique stinging structure

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

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

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

IV) Reproduction

V) Classes of Cnidarians Hydrozoans Leathery or bushy colonies of polyps Siphonphores: drifting colonies of polyps Scyphozoans Jellyfish Larger, bell-shaped medusas Cubozoans Anthozoans Sea Anemones Corals

A) Hydrozoans

B) Scyphozoans

C) Cubozoans

D) Anthozoans

D) Anthozoans