HOW ARE THEY SIMILAR TO PHYLUM PORIFERA? No digestive system No circulatory systems Both have 2 cell layers Some are sessile
How are they different from Phylum Porifera? Cells bound by inter-cell connections Muscles Nervous system Have special cells called CNIDOCYTES Some are mobile
Main Charcteristics • What type of symmetry do they have?
What are their stinging cells called? What are they used for? • Have tentacles with stinging cells called____________________. • What are they used for?
Occur in 2 basic forms 1. sessile________ 2. free floating__________
How many tissue layers? tissues composed of 95% or more water How do they move? http://www.pbs.org/kcet/shapeoflife/episodes/move_explo1.html
Homework: Jelly Life Story http://bcs.whfreeman.com/thelifewire/content/chp32/32020.html
Classification Kingdom Animalia Phylum Cnidaria Class Cubozoa Class Hydrozoa Class Scyphozoa Class Anthozoa
Cubozoa: "box jellies" Mostly found in tropical waters Actively hunts prey Four evenly spaced out tentacles Extremely powerful venom Well-developed, complex eyes-24 in all
Hydrozoa: "polyp colonies" Live in colonies Colonies have separate sexes Some polyps asexually reproduce by budding Polymorphism: specialized polyps
Scyphozoa: "true jellies" Mostly exist as a medusa Found at all depths all over the world Four oral arms Contract muscles to move
Anthozoa: "sessile polyps" No medusa stage Symbiotic relationship with zooxanthellae (photosynthetic algae) Corals secrete calcium carbonate Mesenteries (longitudal sheets of tissue)