Download Phylum Cnidaria

Phylum Cnidaria
Hydra, jellyfish, coral, & sea
anemones
Cnidaria – get name from cnidocytes
or stinging cells along their tentacles
•Class Anthozoa: Sea Anemones
Giant Sea Anemone
Rosy Sea Anemone
Clown fish and sea anemone
Class Anthozoa: Corals and Sea
Anemones
Brain Coral
Coral
Colt Coral
Elkhorn Coral
Cabbage Coral
Flower Coral
Sun Coral
Sea Pen
Sea Fan
Sea Plume
Class Hydrozoa:
Hydra, Portuguese Man 0’ War
Portuguese Man
0’ War
(A colonial
hydrozoan)
One specialized
polyp is enlarged
and full of air to
keep it afloat, while
the other are below
the water for
feeding and
reproduction
Portuguese Man 0’ War
Tentacles of Physalia physalis
Class Scyphozoa: True
Jellyfish
Fried egg jelly
Jellyfish
Purple lion’s mane
Sea Nettle
Giant Jelly off Coast of Japan
Class Cubozoa: Box Jellyfish
Characteristics:
• Soft bodied
• 2 Body forms – Polyp and Medusa
• Have stinging tentacles with nematocysts
• Radial symmetry
•Internal space – gastrovascular cavity
• Hydrostatic skeleton (such as sea
anemones
Specialized structures:
•2 Tissue layers: Ectoderm and Endoderm
Jellylike substance in between - mesoglea
• Contracting cells contain muscle fibers
• Nerve cells form a nerve net – detect
stimuli
• Cnidocytes that contain nematocysts
(stinging structures) mostly on
tentacles.
Mode of nutrition:
• Carnivores
• Catch prey using tentacles.
• Digestion in gastrovascular cavity
• Mouth is used for ingestion and excretion.
Movement:
• Sea anemones uses its hydrostatic
Skeleton for the body to get taller.
• Jellyfish move by jet propulsion.
•Hydras often do somersaults!
Reproduction:
1. Sexually:
• Sexes are often separate*
• External fertilization takes place in the H2O
• Zygote develop into a larva (the planula)
• Larva develop into a polyp.
• Polyp buds to form a medusa.
*Hydra is a
hermaphrodite
and contains
male and female
structures.
2. Asexual reproduction:
•Budding
Bud becomes new Hydra