start presentation. by eric mcclung & mitchell christopher play intro soundplay background sound
Post on 04-Jan-2016
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By Eric McClung
& Mitchell Christopher PLAY INTRO SOUND PLAY BACKGROUND SOUND
Habitat
Food
Importance to Humans
Classes
Reproductive system
Credits
Nervous System
Unique Characteristics
Respiratory System
Circulatory system
Excretory System
Digestive system
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• Most anywhere on earth
• ¾ of the planets surface
• Can live in fresh and salt water as well as on land
• Must be a damp environment
• If the plants are scarce so are mollusks
• Can be found in ponds lakes and rivers
Squid video
• Some live on sediment bottom, or cling to rocks
• Some will glide over reefs
• Other types live in the deep dark part of the sea like the squid
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• They feed on most anything • Gastropods are usually vegetarians• Slugs and Snails eat plants• Limpets and Winkles eat algae• Many mollusks have a radula • The Radula is used to rasp away at
food• It is covered with tiny little “teeth”
Definitions: limpets, Winkles
• Gastropods, like whelk usually eat dead animals and few species hunt
• Marine Carnivores, cephalopods, are an extremely formidable predator
• The squid and cuttlefish have two extra long tentacles that capture their prey
• The squid has very good eye sight that also helps them judge distance
Return to menuDefinitions: whelk
• 30,000 tons of squid are caught off the coast of Argentina alone
• Roman is the most popular type of snail that is eaten in France, there it is called escargots
• Some mollusks are used for buttons and calcium pills
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Gastropods = snails slugs etc.
• Most live in the ocean
• Five of the seven that live in the ocean are: Chiton, tusk shells, cephalopods, monolacophs, and aplacophs
• Cephalopoda-(web definition)
• Bivalvia-(web definition)
• Gastropoda- (web definition)
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• Some mollusks fertilize themselves • Others will swarm and breed• Some will only use a single partner• Mollusks also produce large amounts
of eggs• Many are eaten before they hatch• When a mollusks reproduces sexually
it reproduces with a large organ called a gonad
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A diagram of the inside of a squid
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• The nervous system is quite unique it includes a ring of a nervous tissue that is around the esophagus that is then connected with two pairs of vertical nerve cords that got to the muscles of the foot and mantle
• No formal nervous system but it has a series of ganglia that conduct impulses
• Some mollusks have simple nervous systems like clams, but others have more complex nervous system like octopuses
Return to menuDefinitions: ganglia, esophagus
• There are ten thousand species of mollusks
• Most mollusks have a soft body with a hard shell (ex. Snails)
• Some squids have nerve cells about 100 times bigger than human nerve cells.
Rare Squid sighting in natural habitat video Return to menu
• Numerous mollusks have gills to absorb water into the mantle cavity, once in the cavity the oxygen will be siphoned
• After the oxygen has been removed it will enter the blood stream, while simultaneously removing carbon dioxide
• Land dwellers will have lungs which are always moist, also the opening or mouth is usually found behind the head
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• Mollusks have a heart with extensive branched and blood vessels that carry blood from the heart to all other parts of the body
• There hearts are pericardial cavities, which is a part of the body cavity or coelom
• Contains a simple heart
• In a slow moving Mollusks, blood is pumped from the heart through open spaces called sinuses
• Blood then travels into vessels that move through gills and then returns to the heart
• Referred to as an “open” circulatory system
Return to menuDefinitions: , sinuses, open circulatory system, coelom
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• A mollusks’ excretory system has an anus it also has an organ called a nephridium that get rid of the wastes
• Made up of glandular epithelium which takes nitrogenous wastes from blood passing though them
• The waste material is then discharged to the outside by pores near the anus
Definitions: nephridium
• A mollusks must capture its food through a siphon system that travels to a digestive gland and into its intestine, then the waste is removed by anus
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