Transcript ENVI 21 Life in the Ocean

I.
Cnidaria
D.
Anthozoa
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More species than Hydrozoa or Scyphozoa
No medusa stage
Polyps more complex than in other classes
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1.
Gut contains septa to add surface area for digestion of prey
Passive suspension feeders and predators
Solitary forms
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2.
Anthopleura xanthogrammica
Sea anemones – polyps may be very large
Colonial forms
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b.
c.
d.
e.
Corals
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Stony corals – branching and doming (massive)
- Some build reefs in tropics
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Soft corals
Precious corals – Protein skeleton + spicules
Gorgonians (sea whips, sea fans) – Tough protein skeleton
Sea pens – No skeleton
Sea pansies – No skeleton; some bioluminescent
Branching Corals
Doming Corals
Soft Corals
Precious Corals
I.
Cnidaria
D.
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2.
Anthozoa
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Anthopleura xanthogrammica
More species than Hydrozoa or Scyphozoa
No medusa stage
Polyps more complex than in other classes
Gut contains septa to add surface area for digestion of prey
Passive suspension feeders and predatorsolitary forms
Sea anemones – polyps may be very large
Colonial forms
a.
b.
c.
d.
e.
Corals
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Stony corals – branching and doming (massive)
- Some build reefs in tropics
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Soft corals
Precious corals – Protein skeleton + spicules
Gorgonians (sea whips, sea fans) – Tough protein skeleton
Sea pens – No skeleton
Sea pansies – No skeleton; some bioluminescent
Gorgonians (Sea Whips)
Gorgonians (Sea Fans)
I.
Cnidaria
D.
Anthozoa
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More species than Hydrozoa or Scyphozoa
No medusa stage
Polyps more complex than in other classes
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1.
Gut contains septa to add surface area for digestion of prey
Passive suspension feeders and predators
Solitary forms
•
2.
Anthopleura xanthogrammica
Sea anemones – polyps may be very large
Colonial forms
a.
b.
c.
d.
e.
Corals
•
Stony corals – branching and doming (massive)
- Some build reefs in tropics
•
Soft corals
Precious corals – Protein skeleton + spicules
Gorgonians (sea whips, sea fans) – Tough protein skeleton
Sea pens – No skeleton
Sea pansies – No skeleton; some bioluminescent
Sea Pens
I.
Cnidaria
D.
Anthozoa
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More species than Hydrozoa or Scyphozoa
No medusa stage
Polyps more complex than in other classes
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•
1.
Gut contains septa to add surface area for digestion of prey
Passive suspension feeders and predators
Solitary forms
•
2.
Anthopleura xanthogrammica
Sea anemones – polyps may be very large
Colonial forms
a.
b.
c.
d.
e.
Corals
•
Stony corals – branching and doming (massive)
- Some build reefs in tropics
•
Soft corals
Precious corals – Protein skeleton + spicules
Gorgonians (sea whips, sea fans) – Tough protein skeleton
Sea pens – No skeleton
Sea pansies – No skeleton; some bioluminescent
Sea Pansies
I.
Cnidaria
E.
Cubozoa
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Sea wasps, Box jellyfish
Small medusae
Life cycles poorly known; include polyp stage
Highly toxic
Eat fishes, worms, arthropods
II.
Ctenophora
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Comb jellies
Exclusively marine (100 species)
Radial symmetry
Eight rows of ciliary combs
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Used for swimming video
Carnivorous
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Lack nematocysts
Capture prey with sticky colloblasts
May occur in swarms
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Heavy predators on plankton, including fish larvae
Body forms
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Tentaculate – Planktivores
Lobate - Ctenophorivores
II.
Ctenophora
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Comb jellies
Exclusively marine (100 species)
Radial symmetry
Eight rows of ciliary combs
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Used for swimming
Carnivorous
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Lack nematocysts
Capture prey with sticky colloblasts
May occur in swarms
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Heavy predators on plankton, including fish larvae
Body forms
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Tentaculate – Planktivores
Lobate - Ctenophorivores
Pleurobrachia
Tentaculate
Beroe
Lobate
III. Worms
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Body shape very common in invertebrates
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Especially in mobile invertebrates
Flexibility
Maneuverability
Bilateral Symmetry**
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Cephalization
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“Head” end with
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Accumulation of nerve tissue (“brain”)
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Sensory structures
Anterior – Posterior
Dorsal - Ventral
Left - Right
Fig. 7.12
IV. Platyhelminthes
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Flatworms - Dorsoventrally flattened
Simplest bilaterally symmetrical organisms
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First organs and organ systems**
Central nervous system
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Simple “brain” coordinates muscle movements
Incomplete digestive system
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Mouth but no anus
Similar to Cnidaria and Ctenophora
Mesoderm**
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Cell layer between endoderm and ectoderm
Gives rise to muscles, reproductive system
IV. Platyhelminthes
A.
Turbellaria
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Mostly free-living carnivorous species
Most commonly seen (Why?)
Some live as commensal animals inside other
invertebrates (oysters, crabs, etc.)
IV.
Platyhelminthes
B.
Trematoda (Flukes)
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Most species (6000)
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Complex life cycles
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C.
Parasitic – Feed on tissues, blood, gut contents
Adults live in vertebrate host (fish, whale, bird)
Larvae may inhabit invertebrates (intermediate hosts)
Vertebrate eats intermediate host (clam, snail, etc.)
Cestoda (Tapeworms)
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Parasitic
Live in vertebrate intestines
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Head attaches to intestine wall with suckers or hooks
Gutless – absorb nutrients through body wall
May reach 50 feet!! (sperm whales)
V.
Nemertea
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Ribbon worms
Cosmopolitan
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Complete digestive tract**
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Mouth and anus
Circulatory system**
Use long, fleshy proboscis to capture prey
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Most common in shallow, temperate regions
Feed on crustaceans and worms
May be cryptic or conspicuous
Can reach 30 m in length!!