phylum cnidaria hydra, jellyfish, coral, & sea anemones
TRANSCRIPT
Phylum CnidariaPhylum CnidariaHydra, jellyfish, coral, & sea Hydra, jellyfish, coral, & sea
anemonesanemones
Phylum CnidariaPhylum Cnidaria
Examples?Examples?• Sea anemonesSea anemones• CoralsCorals• Sea PenSea Pen• Sea FanSea Fan• Sea PlumeSea Plume• HydraHydra• Jelly fishJelly fish• Portuguese Man o’ WarPortuguese Man o’ War• Box Jelly FishBox Jelly Fish
I. Body StructureI. Body Structure
A. A. PolymorphismPolymorphism = =
more than one body formmore than one body form
1. 1. PolypPolyp
2. 2. MedusaMedusa
B. PolypB. Polyp
• Tube with tentacles Tube with tentacles
around the moutharound the mouth
• SessileSessile
Coral polyp
C. MedusaC. Medusa
• Umbrella shapeUmbrella shape
• Tentacles around mouthTentacles around mouth
• Motile, Free-swimmingMotile, Free-swimming
D. TentaclesD. Tentacles• Have Have nematocysts nematocysts
(stinging (stinging
cells)cells)
• Coiled thread Coiled thread discharges discharges
like a like a harpoonharpoon
• Contains Contains neurotoxinneurotoxin
• Paralyzes Paralyzes preyprey
Discharged nematocyst
IV. HabitatIV. Habitat
A. AquaticA. Aquatic
1. Most Marine1. Most Marine
2. Few fresh-water2. Few fresh-water
V. FeedingV. Feeding
A. Carnivores A. Carnivores
(predators)(predators)
B. Process of feedingB. Process of feeding
1. Tentacles sting prey with1. Tentacles sting prey with
nematocystsnematocysts
2. Tentacles grab prey2. Tentacles grab prey
3. Prey pulled into mouth3. Prey pulled into mouth
Lion’s mane eats another jelly
Process of feedingProcess of feeding
4. Prey stuffed into 4. Prey stuffed into gastro-gastro-vascular cavityvascular cavity (GVC)* (GVC)*
5. GVC makes 5. GVC makes enzymesenzymes, extra-, extra-cellular digestioncellular digestion
6. Undigested food back out 6. Undigested food back out mouthmouth
**incomplete digestive tract (no incomplete digestive tract (no anus)anus)
VI. RespirationVI. Respiration
• Via diffusion Via diffusion
• Body is two cell layers Body is two cell layers
thickthick
IX. ResponseIX. ResponseA.A. No cephalization or nervous systemNo cephalization or nervous system
B.B. Nerve net around mouthNerve net around mouth
IX. ResponseIX. Response
C. Sensory cellsC. Sensory cells
1. Chemoreceptors (chemicals)1. Chemoreceptors (chemicals)
2. Thigmoreceptors (touch)2. Thigmoreceptors (touch)
3. Photoreceptors (light)3. Photoreceptors (light)
OcelliOcelli (eyespots) (eyespots)
4. 4. StatocystsStatocysts (balance) (balance)
X. LocomotionX. Locomotion
A.A. Medusa motileMedusa motile, free-swimming, free-swimming
B.B. Polyps sessilePolyps sessile
Exceptions: Exceptions:
1. Hydra tumbles on tentacles1. Hydra tumbles on tentacles
2. Sea anemones glide on pedal 2. Sea anemones glide on pedal discdisc
XI. ReproductionXI. Reproduction
1. 1. Asexual Asexual
budding from polyps or medusaebudding from polyps or medusae
2. 2. SexualSexual
a. Medusae release sperm & eggsa. Medusae release sperm & eggs
b. Some monoecious, some b. Some monoecious, some dioeciousdioecious
c. Larvae free-swimmingc. Larvae free-swimming
XII. Ecological RoleXII. Ecological Role
A.A. Predators and preyPredators and prey
B.B. Neurotoxins in medical researchNeurotoxins in medical research
C.C. Coral – jewelry, building, reefs Coral – jewelry, building, reefs (surfing!)(surfing!)
D.D. Coral reefs - habitat for manyCoral reefs - habitat for many
-great biodiversity-great biodiversity
- protect coastline- protect coastline
E.E. Symbiosis with other organisms Symbiosis with other organisms
Hydra eating DaphniaHydra eating Daphnia
• Hydra eats DaphniaHydra eats Daphnia
Portuguese Portuguese Man 0’ WarMan 0’ War
(a (a Hydrozoan), Hydrozoan), NOT a true NOT a true
jelly fishjelly fish