Invasive and Endangered species categories, though sometimes including similar organisms, vary a great deal in their meaning. Invasive species are species that are not native to an area, but have been introduced into a different location due to a variety of different reasons. While invasive species do not always have an impact on the area they are introduced to, they can also have a vast impact on the ecology and environment they inhabit. Endangered species are those whose population sizes have been decreased dramatically and are now in danger, often times caused by human involvement, but sometimes also because of environmental factors. Corbula amurensis, commonly known as the Asian Bivalve or Amur River clam is an invasive species whose introduction has caused severe stress on the environment it inhabits. Potamilus inflatus, also known as the Alabama Heelsplitter, is another mussel type organism, but is endangered due to the changes its environment has undergone.
The Asian Bivalve (Figure 1) is native to areas such as Korea, Japan and China. It occurs in estuarine and marine habitats in tropical to cold temperate waters. (Potamilus amurensis (mollusc)). Corbula amurenesis is generally a tan, white, or yellow clam. It grows up to about 25 millimeters long, and lives partly buried in sediment. The majority of its diet consists of zooplankton and phytoplankton, which is extracted from water when passing through the clam’s siphons (Cohen). This species was introduced in San Francisco Bay in California (Figure 2) in 1986 during a severe drought. It was brought to this area by the dumping of ships’ ballast water. The Asian Bivalve has caused many problems for the ecology of the San Francisco Bay because of its consumption of large amounts of plankton. Plankton is a major food source for important fish species is San Francisco. Furthermore, when populations of these fish species are dramatically decreasing, other organisms are losing their sources of food, and the...
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