OYSTERSPresented 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.

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