Transcript Oct 4 - University of San Diego

I.
Flowering Plants (Angiosperms)
B.
Salt Marsh Plants
Cord grass (Spartina)
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Fig. 12.8
Salicornia
Salt tolerant terrestrial plants
Salt glands in leaves excrete excess salts
Inhabit temperate soft-bottom coastal areas
Important sources of habitat for birds, etc.
Fig. 12.7
Spartina
Pickleweed (Salicornia)
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Halophyte
Occurs at higher levels in marsh with less inundation
by salt water
Succulent leaves help to dilute salts
I.
Flowering Plants (Angiosperms)
C.
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Mangroves
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Salt tolerant shrubs and trees (80+ species)
Tropical terrestrial plants living in soft sediments, often
organic rich and anoxic
Poor competitors
All share certain characteristics
Salt tolerance (halophytes)
Shallow, broad root system and aerial roots with
pneumatophores (pores for gas exchange)
Salt glands that excrete excess salt
Tough, succulent leaves that store water
Viviparity
Inhabit highly productive ecosystems
Provide important habitat for larval and juvenile
organisms
Protect shorelines against erosion and wave action
Red
Mangrove
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Flowering Plants (Angiosperms)
C.
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Mangroves
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Salt tolerant shrubs and trees (80+ species)
Tropical terrestrial plants living in soft sediments, often
organic rich and anoxic
Poor competitors
All share certain characteristics
Salt tolerance (halophytes)
Shallow, broad root system and aerial roots with
pneumatophores (pores for gas exchange)
Salt glands that excrete excess salt
Tough, succulent leaves that store water
Viviparity
Inhabit highly productive ecosystems
Provide important habitat for larval and juvenile
organisms
Protect shorelines against erosion and wave action
Fig. 6.14
II. Invertebrates - Background
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Domain Eukaryota
Kingdom Animalia
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Multicellular
Invertebrates – No backbone
Vertebrates – Backbone
Estimate - 97% of all animal species are
invertebrates
III. Porifera (Sponges)
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Structurally simplest multicellular animals
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“Complex aggregations of specialized cells”
Cellular level of organization
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No true tissues
No true organs
Most sponges are marine (~9000 species)
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Most speciose in shallow tropical waters
All are sessile (attached to substrate)
Diversity of shapes, sizes, colors, habitats
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Encrusting sponges
Glass sponges (Hexactinellids) – Silica skeleton
Boring sponges (Ex - Cliona)
Sclerosponges – Calcium carbonate skeleton
Fig. 7.2
III. Porifera (Sponges)
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Structurally simplest multicellular animals
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“Complex aggregations of specialized cells”
Cellular level of organization
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No true tissues
No true organs
Most sponges are marine (~9000 species)
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Most speciose in shallow tropical waters
All are sessile (attached to substrate)
Diversity of shapes, sizes, colors, habitats
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Encrusting sponges
Glass sponges (Hexactinellids) – Silica skeleton
Boring sponges (Ex - Cliona)
Sclerosponges – Calcium carbonate skeleton
III. Porifera (Sponges)
A.
Body Plan (Structure)
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Ostia – Small pores through which water enters
Osculum – Large opening through which water exits
Pinacocytes – Flat cells covering outer surface
Porocytes – Canal allows water to enter
Choanocytes – Collar cells; line chambers
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Beat flagella to pump water through sponge
Collar traps food particles
Spongin – Elastic protein that makes up body of many
sponges
Spicules – Calcareous or siliceous structures that provide
structural support and discourage predators
Amebocytes – Secrete spongin and spicules
Fig. 7.1
III. Porifera (Sponges)
B.
C.
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2.
Feeding
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Suspension feeders
Filter feeders (active suspension feeders)
Pump water across filter (Video)
Ingest plankton and organic particles
Important consumers of particles in many areas
Reproduction
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Asexual
Fragmentation
Sexual
Spawning
Gametes produced by amebocytes, not gonads
Most sponges hermaphroditic
Internal fertilization
Planktonic larva = parenchymula
Spawning  Larva  Settlement  Metamorphosis
Fig. 7.4
Link: Sponge Spawning Video
IV.
Cnidaria
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Includes 9000+ species
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Sea anemones
Corals
Jellyfishes
Body Plan
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True tissues**
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Perform specific functions
Body forms
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Polyp
Medusa
Radial symmetry
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Oral surface
Aboral surface
Fig. 7.6
IV. Cnidaria
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Body Plan
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Systems
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Nervous system
Digestive system
Cell Types
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Epidermis – External cell layer
Mesoglea – Middle layer, usually acellular
Gastrodermis – Inner cell layer
Nematocysts
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Stinging cells
Defense
Prey capture
www.calacademy.org/research/izg/nematocyst.htm
IV.
Cnidaria
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Hydrozoa (Class)
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Polyp forms
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Often colonial
Polyps typically small
Polyps may be specialized for
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Feeding
Millepora species
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Reproduction
- Some produce small medusae that produce gametes
- Ciliated free-swimming planula larva  Polyp
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Defense
Medusa forms – Usually small
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May be colonial
Siphonophores – Colonial (Ex - Portugese man of war)
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Specialized polyps for swimming, feeding, reproduction
Fig. 7.8
IV. Cnidaria
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Scyphozoa
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Desmonema glaciale
Medusa stage dominant
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Polyps very small – produce juvenile medusae
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Polyp stage absent in some species
Medusae may get very large
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Ex – Cyanea capillata (Lion’s Mane)
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Bell more than 2 m in diameter
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Tentacles to 60+ m long
Swim by contracting bell rhythmically
Cyanea capillata
IV.
Cnidaria
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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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Gut contains septa to add surface area for digestion of prey
Passive suspension feeders and predators
Solitary forms
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Anthopleura xanthogrammica
Sea anemones – polyps may be very large
Colonial forms
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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