Salmon External Anatomy Vocabulary
Dorsal: The top of the fish, or the back of a human.
Ventral: The bottom of the fish or the belly of a human.
The Fins
Dorsal Fin: Provides steering control and balance
Adipose Fin: There is no known use; however, this fin is often clipped to differentiate hatchery fish from wild fish
Pectoral Fins: Aids in stabilization, maneuvering, and braking.
Pelvic Fins: Aids in stabilization, maneuvering, and braking.
Anal Fin: Provides balance.
Caudal Fin: Also known as the tail fin it provides the main source of propulsion. Females use their caudal fin to dig their redd (nest).
Body Shape
The overall body of a salmon is streamlined for easier movement through the water.
External Body Parts
Nares: Fish use their nostrils for smelling, not for breathing.
Eyes: Fish eyes can see both to the left and right at the same time, and each eye can move independently.
Mouth: Allows the fish to take in food. All salmon have teeth, but some have bigger teeth than others.
Operculum (Gill Cover): Protects the gills, similar to how a human’s rib cage protects the lungs.
Lateral Line: A line that runs down the center of the fish. The line has little holes in it to help the fish sense vibrations in the water. These vibrations help fish tell the movements of other animals and objects in the water.
Scales: Protective outer layer. Scales overlap one another to form armor like plating around the fish. An up-close look at a scale reveals rings that can be used to determine the age of a fish, much like counting the rings on a tree.
Caudal Peduncle: The narrow region of the body of a fish just in front of the caudal fin. Provides the muscle to power the caudal fin.
