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.
Bowfin and Snakeheads: Distinguishing Features. Snakeheads (family Channidae) from Africa and Asia are occasionally imported illegally into Texas. They closely resemble native bowfin (Family Amiidae) but are unrelated. This page depicts one species of snakehead. About 27 others have been identified, some with different color patterns.