Daily Activity 4-12-2012
• Get out your notebooks and be
prepared to take notes on Cnidaria.
Phylum Porifera
Sponges
Phylum Cnidaria
Jellyfish, corals .....
• Don’t forget – sponges are
animals and belong to the
Animal Kingdom
1. Multicellular
2. No organs or body systems
3 . Cellular digestion
(heterotrophic)
4. Asymmetry
Sponges
are
SESSILE –
they do not
move
They obtain
food by
FILTER
FEEDING
Reproduce sexually (sperm and eggs)
Reproduce asexually (regeneration)
Skeleton composed of spongin (soft)
and spicules (hard)
Sponge Anatomy
Amebocytes - cells
within the sponge that
move around
supplying nutrients
and taking away
waste
Pacific Northwest Locals
Purple Sponge
Cnidarians - jellyfish, coral, hydra,
sea anemone
*Named after the stinging cells found on
their tentacles called CNIDOCYTES
Characteristics of Cnidarians
· Tentacles
· Cnidocytes (stinging cells)
· Nematocysts
(barbs)
· Gastrovascular
cavity (digestion)
Most Cnidarians have radial symmetry
Cnidarians have two body forms:
polyp (vase shaped)
medusa (cup shaped)
Portuguese Man of War - cnidarian that floats in the
water and has long tentacles
Pacific Northwest Locals
Fish Eating Anemone
Giant Lion’s Mane Jellyfish
White Spotted Rose
Anemone
Egg Yolk Jellyfish
Crimson Anemone
http://www.calvintang.com/blog/2007/06/giant-jellyfish
The Hydra is a freshwater cnidarian
What kind of symmetry does hydra have?
Is it a medusa or a polyp?
Hydra
• Predatory animals
• They can be found in most unpolluted freshwater ponds, lakes, and streams in the temperate
and tropical regions and can be found by gently
sweeping a collecting net through weedy areas.
• Hydras are generally sedentary or sessile, but do
occasionally move quite readily, especially
when hunting.
Video of hydra at
http://www.microscopyu.com/moviegallery/pondscum/hydra/
Pacific Northwest Locals
Pink Mouth Hydroid
Coral Reefs are made from the skeletons of
cnidarians
Pacific Northwest Locals
Soft Coral
Cup Coral
Multimedia
Sponge Images and Videos http://www.junglewalk.com/video/Sponge-movie.htm
Cnidarian Images and Videos http://www.junglewalk.com/video/Coelantrate-movie.htm
General Invertebrate Movies at National Geographic
--- really good video on the portuguese man of war (under
invertebrates)
Hydra Video at http://www.schooltube.com/video/55045/Hydra