CnidariaHydras, anemones, jellyfish, corals

Key Characteristics Lives both in salt and fresh water

Simple nervous system’

Stinging cells

Radial Symmetry

Two embryonic cell layers

Anatomy Nerve net- areas densely pact with nerve cells

Statocyst- an organ for movement

Ocelli- simply sensory organ

Two-way digestion- food enters and leaves same cavity

Hydrostatic Skeleton- muscle changes with liquid

Anatomy cont. Tentacle- surrounds mouth to aid food captures Nematocyst- Harpoon like stinging cells

Mouth- takes in food and removes waste

Gastrovascular cavity- distributes digested nutrients

Bud- group of cells that grows into new organism

Digestion Two way Digestion

Mouth also anus

Gastrovascular cavity digests and distributes food

Waste pushed out mouth

Tentacles aid in releasing waste

Respiration Breath through diffusion

Oxygen obtained through water

Diffuses oxygen higher to lower concentration

Diffuses in gastrovascular cavity

Possible through thin cell layers

Internal Transport Gastrovascular cavity breaks down

particles

Cells surrounding cavity absorb

Nutrients distributed by cells

Thin cells create semipermeable body

Unused particles leave through anus

Excretion Gaseous wastes eliminated by diffusion

Dissolved wastes leave through diffusion

Waste created in gastrovascular cavity

Undissolved waste leaves through anus

Waste is taken in and leaves through mouth

Response Nematocyst defends animal

Nerve nets aid in response

Ocelli

Does not have brain or eyes

Nematocyst located all over

Movement Hydrostatic skeleton

Moves with muscle contractions

Shape changes depending on fluid

Without liquids there is no movement

Expelling liquids propels movement

Reproduction Both asexual and sexual reproduction

Budding creates genetic clone

Sperm and eggs are released in water

Combined in water create zygote

Zygote settles and grows into adult polyp

Examples Cubozoa- box jellyfish

Scyphozoa- moon and purple jellyfish

Anthozoa- anemone, coral

Hydrozoa- hydra, Portuguese man of war

Divided into fresh and salt water groups

Facts 10,000 different species

130 species in Sydney Harbor

Only two are dangerous to humans

Comes from Greek cnidos or stinging nettle

Have no developed organs

Works Cited http://classconnection.s3.amazonaws.com/556/flashcards/1811556/gif/cnidaria_hydra1365168401629.gif http://library.thinkquest.org/28751/review/animals/2.html http://www.vattenkikaren.gu.se/fakta/arter/cnidaria/overcnid/nass04e.html http://www.ncbi.nlm.nih.gov/pubmed/7833621 https://www.boundless.com/biology/the-musculoskeletal-system/types-of-skeletal-systems/hydrostatic-ske

leton-exoskeleton-and-endoskeleton/ http://www.angelfire.com/mo2/animals1/phylum/jellyfish.html

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http://upload.wikimedia.org/wikipedia/commons/3/32/Marrus_orthocanna_crop.jpg https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRAIwYYk21MD6R0-MTzEXMwq2mdbzM18Af9Dc

6sxswrWOb1mODMsQ

http://cnidarianh.blogspot.com/2007/02/feeding-respiration-excretion.html http://w3.shorecrest.org/~Lisa_Peck/MarineBio/syllabus/ch7invertebrates/Invertwp/invert_wp_05/cnidaria/

miles1/Cool.htm

http://www.mesa.edu.au/cnidaria/images/jelly_life-cycle.jpg https://lh4.googleusercontent.com/-nv2CohpE238/TYumw6y9wHI/AAAAAAAAJ-A/X-wIl_VNczQ/s1600/Pictur

e%2B14.png

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