Transcript Chapter 33 - CanonMacZoology

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
CnidariaFeeding/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 organables 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.