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.
The northern snakehead is an aggressive freshwater fish that can grow to be about 4 feet long. It has been found in a variety of freshwater lakes, swamps, ponds, and streams of various temperatures, but cannot tolerate saltwater.