Study Handout

Hunter Prater

Daniel Kirby

B7

Honor Bound

Mollusks Outline

Examples of Mollusks-

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Body Structure of a Mollusk-

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Diversity/Classes-

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Three Species-

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  Nervous System-

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Reproduction-

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Symmetry-

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Circulation-

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Digestion/Gas Exchange-

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Excretion of Wastes-

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Class Specimens

The specimens we observed were Chiton (Katherina), Squid (Loligo), Land Snail (Helix), Clam (Anodota), Zebra Mussels (Dreissena), Limpet (Patellogastorpoda), and Sea Slug (Dendronotus).

Dissection

The part that is being pointed to with the silver pointer is the arm of the squid.

The big part in the middle that is being pointed to is the Buccal mass of the squid.

The silver things are pointing at the Mantle of the squid.

The silver is pointing at the Siphon.

The silver is pointing to the Sucker of the squid.

The silver is pointing to the Tentacle of the squid.

Three Species Examples

The Nudibranch is one example of a Mollusk and it's often referred to as the sea slug.  Its classification is the Berghia Coerulescens.  The Nudibranch's can live in almost any depth of water but they live their best in shallow warm waters.  It sheds its shell after its larval stage and is basically a slug with no shell for the rest of its life.  It has an external gill cluster that allows the animal to breath.  Some believe that it has such bright colors because of the fact that they are trying to warn other animals away from eating them because they will taste bad.  All nudibranchs are carnivorous and eat sponges or hydroids.

Another example of a Mollusk is the Blue-ringed Octopus.  Its binomial nomenclature is Hapalochlaena lunulata.  This animal is considered one of the worlds most venomous marine animals.  The brown patches on the octopus darken when it becomes agitated.  They usually feed on small crabs or shrimp but if they can catch small fish they will eat them also.  They pounce on their food and paralyze it with their venom and then crush there food with their beak and tear of parts of their catch.  The venom in this creature is strong enough to kill humans.  The venom is produced by bacteria in the salivary glands.  If your bit by this creature often you will not know your infected until your dead.

  A final example of Mollusks is the Colossal Squid.  The binomial nomenclature of it is Mesonychoteuthis hamiltoni.  They are around 39-46 feet long making them the largest known invertebrate in the world.  The Colossal Squid has suckers lined with small teeth but also sharp hooks so their prey sticks to their arm.  This is different from regular squids because they do not have the sharp hooks.  This creature has the largest eyes of any animal in the animal kingdom.  The Squid lives from Antarctica all the way to the southern tip of South America, South Africa, and New Zealand.  It feeds on large fish and doesn't need that much food a day because it has a really slow metabolism.

  

The Major Classes

  There are three major classes for the Mollusks.  These classes are the Bivalves, Gastropods, and the Cephalopods.  Some examples of Bivalves are Clams, Oysters, Scallops, and Mussels.  Some examples of Gastropods are Snails, Whelks, periwinkles, abalone, and slugs.  Finally some examples of Cephalopods are octopuses, squids, and Nautilus.  

Summary on Article

  Dams are being removed more and more  because of the fact that it is helping the ecosystem function.  There was an experiment done around twenty-two small dams in Alabama to observe the life of Mollusks.  Sites that are up and down stream from dams did not have that many differences in their habitat.  Streams that had intact dams had a higher mussel catch rate and there was higher taxon richness than the small streams that didn't have dams.  

  The mollusks found in the streams were Deposit-feeding Snails, Exotic Bivalve, and the Fingernail Clams.  They think that if dams are intact it enhances mollusk habitats in down stream reaches.  Streams that have intact dams are proven to be more stable than ones that are not.  Streams that have dams that are not intact are not as clean and can have parts of construction from the dam when it was taken down.  The dams that are not intact need to be fixed because they can harm the Mollusks and hurt them in time to come if we don't do anything about it.  

This Article was found on http://web.ebscohost.com/ehost/detail?vid=4&hid=12&sid=53170813-764d-43e7-95c1-58a94008881f%40sessionmgr111&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=a9h&AN=66697468  

   

Mollusks a case study