1. Cnidarians (Coelenterates)

2. Phylum Cnidaria (Coelenterata) Class Hydrozoa = Hydra POLYP body form = “vase shaped” ; sessile Most live in colonies. 1 of 3 classes within Phylum Cnidaria

3. Phylum Cnidaria (Coelenterata) Class Scyphozoa: “Cup Animals” –Medusa body form (bell-shaped); swimming –Commonly known as jellyfish –“Portuguese Man-o-war” –200 different species

5. Phylum Cnidaria (Coelenterata) Class Anthozoa: “Flower Animals” –6,100 different species –Sea Anemones, Corals –Coral Reef = 30 degrees North or South of the equator, shallow water for photosynthetic algae that live in symbiosis with coral

6. Classification Common Name: Hydra Scientific Name: Hydra Phylum: Cnidaria Class: Hydrozoa Other: Phylum Coelenterata (Old name)

7. Major Characteristics Body Plan: Hollow, 2 layered sac Body Cavity: Endoderm, Mesoglea (jelly like), Ectoderm Symmetry: Radial - pull in food from all around Cell Specialization: No Organs, Nematocysts = harpoon like stinging cells; neurotoxins cause paralysis

9. Life Support Processes Absorption: Gastroderm; directly into the body wall Feeding: tentacles pull food into the mouth; they are carnivores Digestion: Gastroderm (endoderm), food vacuoles in cells Respiration & Circulation: Gastrovascular inner cavity

11. Life Support Processes Excretion: Mouth opening, diffusion Secretion: sticky base for attachment Response: Nerve Net - contractile fibers in the epidermis; Ocelli - detects light Movement: contractile fibers; tumble motion through the water Reproduction: Asexual = budding; sexual = hermaphrodite (no self fertilization)

14. Life Support Processes Support: tissue layers, hydroskeleton

15. Ecological Relationships Freshwater living Solitary - not colonial like most hydrozoans Carnivorous - predatory lifestyle

16. Body Systems Compared With Humans Tissues - layers like our skin

17. Advancements Over the Previous Phylum Nervous Structure Movement Active Feeding

18. Diagram of Hydra

19. The largest jellyfish is the Arctic Giant Jellyfish: it can have a diameter over 8 ft. with tentacles stretching as long as 120 ft. The most venomous jellyfish is the Australian Sea Wasp; death can occur within 1-3 minutes. The Great Barrier Reef is the worlds largest stony coral structure stretching for 1,260 miles off Northeast Australia.

20. Lion’s Mane Jellyfish

21. Coral Reefs can be visible from the air! Preventing beach erosion

22. Great Barrier Reef - Australia