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Oysters. Presented by: Meagan Wright. Classification. Scientific Name: Crassostrea virginica Common Names: Eastern Oyster & American Oyster Phylum Mullusca Class Bivalva or Class Pelecypoda. Descriptipon. Has two shells which are unequal in size and shape.
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Oysters Presented by: Meagan Wright
Classification • Scientific Name: Crassostreavirginica • Common Names: Eastern Oyster & American Oyster • Phylum Mullusca • Class Bivalva or Class Pelecypoda
Descriptipon • Has two shells which are unequal in size and shape. • Vary in length from 2 – 12 inches • The body is deep in the shells and surrounded by a tissue called mantle. • The mantle contains muscle, organs, and membranes. • The shell is held together by a centrally located adductor muscle. • When the oyster relaxes, the shell is opened up by a hinge-like ligament at the narrow end of the shell
Description • Oysters also have a pair of gills located under the mantle. • The gills are covered with hair like structure called cilia. • They are composed of layers of folded filaments, giving them a pleated look. • The gills are used for gathering food and respiration. • The front end of the gills contains the mouth • Oysters do not have heads or brains, they have two nerve centers. • One controls the mouth and mantle. The other controls the internal organs.
Geographic range & Habitat • Found in temperate and tropical oceans. • The American & Eastern Oysters are typically found around the Gulf of Mexico and Atlantic coast of North America. • Live attached to the bottom of the ocean on a hard surface. This area is called oyster beds. • The beds are typically located in estuaries, sounds, bays, and tidal creeks from brackish water to full strength seawater.
Feeding Habits • Eat organic debris called detritus and plankton – microscopic animals and plants. • Create a current in the water with their cillia. The water enters their gills, and the particles in the water are caught in mucus. • The food is sorted by size. The smaller particles go to the mouth and the larger ones go to the edge of the mantle to be taken out.
Reproductive Habits • European and the Olympia oysters contain both egg and sperm in one. • The egg is fertilized within the body is kept in the gills until shell-bearing larvae is developed. • The American blue point oyster the sexes are separate. • The oysters spawn by releasing sperm and egg into the water to develop into swimming larva called veliger larvae. • In about 2 weeks, the larvae “cement” themselves to something hard where their will remain the rest of their lives.
Interesting Facts • Each ring on an oyster shell tells how long it has lived. • There are 100 species of true oysters. • Oysters can change sex several times throughout their lives, but they are either male or female at any given time. • Oysters are considered a “keystone species” because they provide shelter and habitat for many other estuary organisms, improve water quality, and prevent erosion.
References • http://animals.howstuffworks.com/marine-life/oyster-info1.htm • http://www.smithpointseafood.com/Oyster.htm • http://score.dnr.sc.gov/deep.php?subject=2&topic=15 • http://www.rawfish.com.au/images/-tassie-oyster-pacific-oyster-tasmania-aphrodisiac1.JPG