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
Egg Yolk Jellyfish
Giant Lion’s Mane Jellyfish
http://www.calvintang.com/blog/2007/06/giant-jellyfish
Fish Eating Anemone
Crimson Anemone
White Spotted Rose
Anemone

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 fresh-
water 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
Cup Coral
Soft 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