Term
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Definition
| Sponges are sesille suspension feeders. Food is passed through the spongocoel and then flows out through the osculum. They have choanocyte cells whose flagellum createsa current. Food is captured in mucus, and throught phaogcytosis are captured by an amoebocyte which is capable of movement. The basic structure is simple; water enters through the porocytes which are seperated by the mesohyl. Spongers contain spicules that provide support. |
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Term
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Definition
| The Cnidarians come in two forms: polyps and medusa. Some Cnidarians are only the former, other only the latter. They are the most ancient clade and contains true tissues. Polyps adhere to a subtrate using their tentacles to capture food, the mouth/anus appears on top of the organism. A medusa is the free living form, it's mouth/anus is below. Tentacles are armed with cnidocytes; a stringing capsule with a thread shoots out. They are bilaterial, with a gastovascular cavity and dipoblastic. Between the epidermis and gastrodermis exists the mesohyl. |
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Term
| (Cnidaria) Class Hydrozoa |
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Definition
| The hydrozoans will alternate betwen the polyp and medusa forms. Some, such as the Hydra exist only in the polyp form, they are found only in fresh water. They can reproduce assexually by budding in good conditions, should conditions turn bad they are capable of producing resistant zygotes that remain dormant. |
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Term
| (Cnidaria) Class Scyphozoa |
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Definition
| The medusa stage is most prevalent, those near the coast have a reduced polyp stage while those in the open ocean have none. The live among the plankton. |
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Term
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Definition
| The cubozoans are named for there "cube" shape. They have complex eyes and are usually highly toxic. The sea wasp is an example of these highly toxic species. |
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Term
| (Cnidaria) Class Anthozoa |
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Definition
| The sea anemones and corals belong to this class. They occur only as polyps. |
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Term
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Definition
Turbellaria/Trematoda/Cestoidea
This phylum encompasses flatworms; which are flattened dorso-ventrally such they do not required organs to expel wastes or gaseous exchange. They are acoelomates. |
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Term
(Plathelinthes) Class Turbellaria
[Flatworms & Planaria] |
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Definition
| These planarians move using cilia on there dorsal body, gliding on mucus. Others use muscles to swim throught water. They have senstive eye-spots capable of detecting light. They are hermaphrodites but can also reproduce assexually. |
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Term
(Plathelinthes)Class Trematoda
[Flukes] |
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Definition
| Trematodes and monogeneans are parasites on animals. Blood flukes or Schistosoma cause Schistosomiassis. These blood flukes evade the immune system by changing surface proteins. |
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Term
(Plathelinthes) Class Cestoidea
[Tapeworms] |
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Definition
| The tapeworm is fundamentally evolved for reproduction. The scolex features suckers and hooks to attach it to a portion of the intestines. Absorption of nutrients occurs across the surface area of the tapeworms. Proglottids exist on a ribbon, they are loaded with eggs which are released into the feces. |
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Term
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Definition
| All squids, oysters and clams are part of Mollusca. They have a shell made of calcium carbondate that is lost or reduced in some forms. The three main parts are; a muscular foot, a visceral mass consisting of internal organs and a mantle that forms over the visceral mass. They also have a radula to scrape up food. |
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Term
(Mollusca) Class Polyplacophora
[Chitons] |
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Definition
| The chitons have a main oval shape body with 8 segmented scales on its back. The body is non-segmented. The chiton uses it's muscular foot to grip rocks with suction action. The have no main head. |
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Term
(Mollusca) Class Gastropoda
[Snails & Slugs] |
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Definition
| Most gastropods are marine, but the terrestrial examples are garden snails and slugs. The notable characteristic of gastropods is the phenomenon of torsion - which is the rotation of it's internal vicerseral mass causing the anus to appear above it's head. |
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Term
(Mollusca) Class Bivalvia
[Clams, Oysters & Scallops] |
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Definition
| The bivalves are named for the two halves held by powerful adductor muscles. They are suspension feeders rapped food and then passing the water back out through the excurrent. Mussels hold themselves firmly to substrate by threads. Scallops can move by moving there teeth like chattering teeth. |
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Term
(Mollusca) Class Cephalopoda
[Squids & Octopuses] |
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Definition
| These are active predators with powerful eyes. There shells are reduced and internal They are able to steer by directing the jet of water .The squid is intelligent and capable of learning. Some cephalopods are shelled, these are called ammonites. They have a closed circulatory system. |
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