When an object rests on a surface, such as a table, for example, the downward force it applies to the surface is counteracted by an equal but upwards force, or reaction, applied by the surface. See more at Newton's laws of motion. A response to a stimulus, such as a reflex.
State. Aquatic Invasive Species: Snakehead (PDF | 201 KB). Indiana Department of Natural Resources. Northern Snakehead. Maryland Department of Natural Resources. Northern Snakehead Fish (Channa argus). New York Department of Environmental Conservation.
An invasive species can be any kind of living organismâan amphibian (like the cane toad pictured left), plant, insect, fish, fungus, bacteria, or even an organismâs seeds or eggsâthat is not native to an ecosystem and which causes harm. They can harm the environment, the economy or even, human health.nvasive species are primarily spread by human activities, often unintentionally. People, and the goods we use, travel around the world very quickly, and they often carry uninvited species with them. 1  Ships: Ships can carry aquatic organisms in their ballast water.