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WORM PHLYA• Worms are general grouping
• Worms have bilateral symmetry
– Allows for more sophisticated behaviour
• Worms are the beginning of advanced inverts
– Evolved organs and other specialization
– Evolved complete digestive tracts
– Body cavity/ coelem
• found in most bilateral animals
• organs are suspended in this space
Worm Phylas• Worms are soft bodied so they
mostly live in tubes, burrows or under something
• Feeding ranges from parasites to carnivorous hunters
• Some worms create mucous nets to catch food while they are safe in their burrow
Platyhelminthes - Flatworms
• Advancements include…– Central nervous system (brain)
– Muscles
– Simplest of animals with bilateral symmetry
• Three classes of flatworms– Turbellaria: carnivorous hunters– Trematodes and Cestodes which are both
parasitic
Tapeworm found on Tiger sharks and mackerel.http://www.marineparasitology.com/Papers/Palm%20&%20Klimpel%202007.pdf
biology.unm.edu/.../Summaries/SimpleAnimals.htm
Nemertea- Ribbon worms• Advancements…
–Nervous system with a brain
–Muscles
–Circulatory System with blood vessels
–Complete digestive tract (mouth and anus)
Ribbon worms continued-
• Stretchy bodies (8 in can stretch to 3 ft)
• Gather food with a proboscis that everts from inside them to catch food
• Proboscis may be sticky or poisoned
Nematode - Roundworms-Body cavity
-Have to molt cuticle as they grow
-Live in sediments and tissues of orgs
-parasitic & predatory
Annelida – Segmented Worms
– Head-like area with a brain
– Segmentation- repeated compartments
• Helps with motion
• Allows for appendages
http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20Laboratory/Animal%20Diversity/Lophotrochozoans/img012.jpg
Class Polychaeta • Each segment has a flattened extension called
parapodia• Gills for breathing
Class Oligochaete• burrow in mud and sand• Scavengers
Class Hirudinea• Live on whatever they are “eating”• Parastic / blood sucking• Sucker at each end
www.inhs.uiuc.edu/.../AOGSMNP.OligoIntro.html
aqua.intervet.com/news/2007-11-25.aspx
Sipuncula – Peanut Worms
• Recent studies have placed them with Annelids even though they aren’t segmented
• Bottom dwellers, many burrow
• Deposit feeders
www.ucmp.berkeley.edu/sipuncula/sipuncula.html
www.wildsingapore.com/.../sipuncula.htm
Pogonophora –Beard Worms
• Lack a digestive system
• Symbiotic bacteria at hydrothermal vents provide them food
White Tube worm
Tube worms
www.nematodes.org/.../odl_pogonophora.html
Vent community worms, live in tubesUse bacteria in them to manufacture food
Chaetognatha- Arrow Worms
• All the features of a complex org
• Eyes and a distinct head
• planktonic
• vicious carnivores preying on larvae of other animals
Lophophorates…colonial worms
• All the features of complex orgs
• Lophophore- unique feeding structure with ciliated tentacles
–Suspension feeders
• Two groups-Bryozoans and Phoronids
Phylum Mollusca
• Evolutionary advances in specializing parts of the body
• Advancement in the nervous system– Squid and octopus are as intelligent as some
vertebrates– Allows for more sophisticated behaviors
• Very successful phylum and one of the most diverse
Phylum Mollusca• Wide diversity of form but based on general body plan
http://www.manandmollusc.net/http://palaeo.gly.bris.ac.uk/Palaeofiles/Fossilgroups/Cephalopoda/BAUPLAN.JPG
Mollusc Body Plan
All molluscs have or had: Foot, Mantle, Shell and Radula
Mantle – tissue which secretes shellBilateral symmetryBody CavityOpen circulatory system with
compartmentalized heart (except cephalapods)
Phylum Mollusca
Class Polyplacophora….chitons
http://www.geocities.com/Yosemite/Gorge/5604/chitonsrickettslarge.jpg
Phylum MolluscaClass Bivalvia “two shells”Ex. Clams, mussels, scallops
http://www.sciencedaily.com/images/2006/10/061006072601.jpg
http://www.xconomy.com/wordpress/wp-content/images/2008/12/scallop_eyes.jpg
• Figure 2 Geoduck Clams. Geoducks are a species of long-lived (100+ years) saltwater clams (Panope generosa) native to the northern Pacific coasts of Canada and the U.S. Pacific Northwest. Washington State’s Puget Sound bays and estuaries harbor the highest density of geoducks in the continuous United States (Washington Dept. of Ecology). Photo courtesy of Are Strom. Used with permission.
cses.washington.edu/.../ae/aekeyfindings.shtml
Phylum MolluscaClass Gastropoda “stomach foot”: snails, slugs and limpets
http://www.ucmp.berkeley.edu/images/taxa/inverts/shell_morph.jpg
Phylum Mollusca
Class Cephalopoda…squid, octopus
http://pics.livejournal.com/krakenwakes/pic/00003p9r
Shells of Shellfish• Three layers: conchin, CaCO3
in conchin matrix, and nacreous made of CaCO3 with some conchin in sheet-like pattern (mother-of-pearl).
• Wide variety of shapes.• Reduced shells (sea hares,
squid pen, cuttle bone).• Lost shells (octopus,
nudibranchs)
http://upload.wikimedia.org/wikipedia/commons/thumb/5/50/Valve-InternalView.png/300px-Valve-InternalView.png
Mollusc Locomotion • Have a muscular foot for crawling,
swimming, burrowing
• Modified into tentacles for squid & octopus– Muscles forces water out siphon or funnel for
swimming.
• Byssal threads- protein strands used to anchor some shellfish to a surface
http://www.huntsmanmarine.ca/assets/images/slide18.gif
Sense Organs
Well developed nervous system in cephalopodsChemosensory organs- sense chemicals by smell or tasteCephalopods have highly developed eyes. Distinct images and possibly color (1 species of squid).
• http://images.google.com/imgres?imgurl=http://www.phy.duke.edu/~hsg/54/table-images/scallop-with-eyes.jpg&imgrefurl=http://www.phy.duke.edu/~hsg/54/&usg=__lOBprQin3JucMYHMZe9hGogM0e0=&h=510&w=793&sz=60&hl=en&start=5&tbnid=j5c6lTW_u_E6TM:&tbnh=92&tbnw=143&prev=/images%3Fq%3Dscallop%2Beye%26gbv%3D2%26hl%3Den%26sa%3DG
Interesting Characteristics
Color change in cephalopods using chromatophores.
Cells that contain pigments and are under nervous system and hormonal control.
http://upload.wikimedia.org/wikipedia/commons/3/3d/Striped_pyjama_squid.jpghttp://imagecache01a.allposters.com/images/pic/NGSPOD/124954-FB~Close-View-of-the-Chromatophore-Laden-Skin-of-a-Squid-Posters.jpg
Mollusc Feeding
Radula Used for scraping, boring, and sometime associated with toxins.
www.jaxshells.org/rad.htm
Cephalapods
http://precordialthump.medbrains.net/files/2009/01/octopus-beak.jpg
Cephalopods highly mobile predators.
Catch prey with suckered arms.
Neurotoxins associated with beak in octopus.
Bivalves
• Filter feeding• Water comes through a siphon,
passes over ctenidia, exits over anus and out exhalent siphon
• Siphons are a flexible tube.• Food particles sorted by
ctenidiahttp://static.howstuffworks.com/gif/willow/geoduck-info0.gif
Gastropods• Gastropod feeding habits are extremely
varied, although most species make use of a radula in some aspect of their feeding behavior.
• Some graze, some browse, some feed on plankton, some are scavengers or detritivores, some are active carnivores.
Mollusc Digestion
• Complete digestive system
• Stomach often has a crystalline style- rod with enzymes
•Food then goes to a digestive gland and to its intestine. Waste passed through anus.
How do molluscs reproduce and develop?
http://www.marlin.ac.uk/php/image_viewer.php?images=crefor&topic=Species
Mollusc Reproduction and Development
Separate sexes and sexual reproduction
Some lay eggs and some bear live young
Some with internal and external reproduction
http://1.bp.blogspot.com/_pbKM4qxmq4c/SItJHG3rmHI/AAAAAAAAEms/D2Fh4ujwQ6I/s400/03.jpghttp://homepage.uab.edu/acnnnghm/BY255L/BY255LImages/BY255LImages-Mollusca/WhelkEggCase-2.jpg
Circulatory System exception
• Cephalopods have closed circulatory system.
• More efficient circulation which allows them to be fast hunters.
news.nationalgeographic.com/news/2006/12/0612...
Human and Mollusc Interaction
• Source of food• Shells are a source of calcium for some birds • Crushed shells are used to kill agricultural pests.
Mollusks also nourish humans culturally. • Mollusk shells served as money in some early
cultures• Species health is used in monitoring water
pollution• Many are invasive species
True or False• All cone shells possess a poisonous dart
(their"radula"), with which they harpoon, inject venom and kill their prey. Cone shell venom is toxic enough to hurt or even kill a full-grown man!
http://publications.nigms.nih.gov/findings/sept02/images/shells.jpg
True or False• Most shelled molluscs can make pearls
• They coat the foreign substance with nacre, the same as the lining of their shell.
• Stimulus include organic material, parasites, or even damage
• Pearl oysters take up to 7 years to grow pearls big enough for jewelry.
http://images.google.com/imgres?imgurl=http://2.bp.blogspot.com/_VfjiSyBlALg/SbgT6kWBw4I/AAAAAAAAAOc/-8OW3-ypwc4/s400/Natural%2BPearls%2BCollage.jpg&imgrefurl=http://www.pearl-professor.com/&usg=__RUA4pRNos1yOfGwtkHVWmYmT9d8=&h=400&w=312&sz=21&hl=en&start=34&tbnid=66apw7XW8G4G3M:&tbnh=124&tbnw=97&prev=/images%3Fq%3Dpearls%2Bnatural%26gbv%3D2%26ndsp%3D20%26hl%3Den%26safe%3Dactive%26sa%3DN%26start%3D20
True or False• The largest known bivalve
was a "Giant Clam" (Tridacna gigas which weighed in at an amazing 734 pounds (333kg!!) and was nearly four feet (1.4m!!) in length.
• It can swallow a diver
http://www.waterworxbali.com/Images/Photos/Large/giant-clam-diver.jpg