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By Eric McClung & Mitchell Christopher PLAY INTRO SOUNDPLAY BACKGROUND SOUND

Habitat Food Importance to Humans Classes Reproductive system Credits Nervous System Unique Characteristics Respiratory System Circulatory system Excretory System Digestive system PLAY BACKGROUND SOUND

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 Return to menu

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, WinkleslimpetsWinkles

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 menu Definitions: whelkwhelk

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 Return to menu 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 ) web definition Bivalvia-( web definition ) web definition Gastropoda- ( web definition ) web definition Return to menu

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

A diagram of the inside of a squid Return to menu

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 menu Definitions: ganglia, esophagusgangliaesophagus

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 Return to menu

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 menu Definitions:, sinuses, open circulatory system, coelomsinusesopen circulatory systemcoelom

Return to menu 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 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 Return to menu

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