Caleb Tubbs and Madelyn Showalter Cnidaria Caleb Tubbs and Madelyn Showalter This Photo by Unknown author is licensed under CC BY-SA.

Description Over 11,000 known species Found in aquatic biomes Bodies consist of mesoglea a nonliving jelly structure They are divided into two categories medusa and polyp.

Symmetry Bilateral or Radial

Feeding Carnivores They are predators that feed on shrimp, amphipods, plankton and other small organisms Trap animals with their tentacles Nematocyst is a special cell containing barbed threat that is used for self-defense or catching prey.

circulation Diffusion which allows glucose or amino acids through blocking proteins and starch This Photo by Unknown author is licensed under CC BY-SA-NC.

Excretion Canal like cavity for ingestion, digestion, and egestion

Response No brain or central nervous system Have decentralized nerve nets that have sensory neurons

Polyp are sessile, which means they do not move Polyp are sessile, which means they do not move. When they are young larva, they swim short distances in their environment. Medusa move by jet propulsion using mesoglea to move forward through small bursts. Tentacles help movement and are long appendages  Movement

Reproduction Males release sperm into the water, which then travels into the mouth of females Reproduce sexually and asexually Some contain one sex while other contain both sexes

respiration Respiration occurs through organs such as the trachea, gills, or lungs.

examples Moon Jellyfish Horn Coral Scientific Name: Hydnophora rigida Scientific Name: Aurelia aurita They are 95% water Horn Coral Scientific Name: Hydnophora rigida Went extinct 251 million years ago