Phylum Cnidaria

aquatic, mostly marine

tissue level of organization

• embryonic tissue
• ectoderm (outer skin)
• endoderm (inner skin)

• predatory
• use cnidocytes (venom containing cells) to capture prey.

Polyp- attaches to a surface and has tentacles pointing upward

medusa- jellyfish, free swimming, tentacles pointing downward

• venom containing cells capture prey
• use stinging filament nematocyst which shoots out from the cell at the slightest touch, to inject venom into prey