Section 2 Cnidaria and Ctenophora Chapter 33 Section 2 Cnidaria and Ctenophora

Phylum Cnidaria Body Plan Freshwater hydra, stinging jellyfish, & flowerlike coral Medusa- bell-shaped Polyp- vase-shaped

Cnidaria- Body Plan Epidermis- outer layer Gastrodermis- inner layer Mesoglea- between epidermis & gastrodermis Gastrovascular cavity- single opening or mouth Tentacles- flexible extensions

Cnidaria- Feeding/Defense Cnidocytes- specialized cells used for defense and capturing prey Nematocyst- cnidocyte organelle, long filament coiled up

Cnidaria- Nervous System Nerve net- diffuse web of interconnected nerve cells

Cnidaria Classes Class Hydrozoa Portuguese man-of war Hydra

Cnidaria Classes Class Cubozoa Box jellyfish

Cnidaria Classes Class Scyphozoa Jellyfish

Cnidaria Classes Class Anthozoa Sea anemones & corals

Phylum Ctenophora “Comb-like”/ Comb jellies Move by beating their cilia Have cells called colloblasts, which secrete a sticky substance that binds to their prey- located on two tentacles

Phylum Ctenophora Sensory structure- apical organ- ables ctenophores to sense their orientation in water Bioluminescence- production of light by means of a chemical reaction

REVIEW!!! Describe how cnidarians feed. Name one organism from each of the 4 cnidarian classes. Compare and contrast cnidarians and ctenophores.