Sept. 26, 2011
Phylum Cnidaria
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Class Anthozoa
o Sea Anemones
o larvae are Pelagic- motile in marine habitat
o they are zooplankton- animal plankton not phytoplankton
Anemones
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adults are sessile, however they can move
zoozanthellae are photosynthetic, endosymbiotic algae
o found in all anthozoans
Intertidal zone
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area that is under water for part of the day
intertidal zone of Pacific has more species per sq. meter than most other habitats
Splash Zone
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area directly above intertidal zone
Benthic zone
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bottom of the ocean
Symbiosis
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living together
Parasitism
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one animal living in or on another animal at the expense of the host
Commensalism
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free living, mutualistic relationship
Charles Lyell
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Coral
coral reef formation
continental drift
o there is a hotspot under Hawaii
o fringing reefs form by growing on island's edges
 as the island subducts under the water surface the coral grows larger
 coral dies as it gets too far under water
 new coral builds on top of dead exoskeletons
 only about the top 1 meter is alive- sunlight reaches it
Hawaii's Big Island is over a hot spot creating more island
o tectonic plates are moving and old islands re subducted
fringe reef results
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anthozoan that produces CaCO3 exoskeleton
produces massive amounts of zooplankton, where they settle a new coral is formed
Phylum Platyhelminthes
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Flatworms
no coelom = Acoelomates
Protonephridia- precursor to primitive kidneys
o flame cells - maintain osmotic balance in flatworms
o Marine flatworms are isosmotic with environment
bilaterally symmetrical
no circulatory system
most don't have a complete digestive tract
o no anus
eye spots for detection of light
o present in free living forms
o parasitic forms lack them
o pigment cells receive light and they can determine the direction it came from.
Sept. 28, 2011
Platyhelminthes
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occur in marine, freshwater and terrestrial habitat
some are parasitic
o parasitic forms: in larval stages can detect light
capable of regeneration
o cellular differentiation
Class Trematoda
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Digenetic = two separate parts to their life cycle
Subclass Digenea
o parasitic
o 2 separate hosts for life cycle
o a mollusc is the intermediate host for all
 intermediate host = used for increased amplification, a sexual
reproduction, increased distribution through space
Dicvocoelium dendriticum life cycle:
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definitive host is deer
intermediate host is snail
phoretic (carrier) host is ants
Phototropic
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Positive = moves toward light
Negative = moves away from the light
Parasites
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use only 2 ATPs per 38 available
o not a large amount of energy taken from host
presence of parasites with complex life cycles are indicators of healthy ecosystems.
Reference
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Parasites as Probes for Biodiversity written by Dr. Gardner
E.O Wilson coined term "biodiversity"
Flatworms
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hermaphroditic = both male and female reproductive systems are present
o can self fertilize but usually cross
o Protandrous = testes develop first in sequence of morphological growth
o Protogynous = ovaries develop first in sequence of morphological growth
Digenetic Trematode:
Sept. 30, 2011
Trematodes
Family Schistosomatidea
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means "split body"
digenetic
not hermaphroditic
male and female never spilt from each other
o female is attached to male
important in humans
o Schistosoma mansoni
Schistosoma mansoni life cycle:
Oct. 3, 2011
Flatworms
Hymenolepis tualatinensis Gardner, 1981
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tapeworm
Family Hymenolepididae
name means "membrane with filaments" "of the Tualatin River"
Order Cyclophyllidea
Hymenolepis spp. = many species of the genus Hymenolpeis
o scolex is the head of a tapeworm
o strobilization occurs at neck
o has 3 testes in each segment
o strobia = chain of segments
Mature Segment:
Gravid segment:
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beetle eats the gravid segment in feces
cysticercoids emerge in beetle
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beetle gets eaten by rat
develops into mature tapeworm in rat
if a person eats the beetle with cysticercoids they will become infected
o except H. dininuta
Family Taeniidae
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Beef Tapeworm
o Taenia saginata occurs in people (definitive host)
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Taenia solium Pork Tapeworm
25 other spp.
spread by carnivory
how did people get these tapeworms initially?
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Eric Hoberg: phylogeny of Taeniidae
people shared lion or hyena kills
contracted parasites from the uncooked meat
host switch
o parasite switched from hyenas and lions to humans
Proximate Ecology
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how things are happening right now
Historical Ecology
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looks at history of organisms and phylogenies