http://www.ux1.eiu.edu/~cfruf/bio4950/fish_locomotion.htm
Fish
move in water with great speed and agility. In water fish are
essentially weightless, in other words their ability to float
counteracts the gravitational forces acting on them. How does the
fish move if it is neutrally buoyant and not rising or sinking in the
water? The answer is that when the fish thrusts forward a small
amount of water equal to the mass of the fish is pushed up to the
surface of the body of water. This push of water is the
counterforce on gravity and causes the fish to move.
A fishes fins and tail also play a major part in their movement and velocity through the water. When water flows past the fish, the energy exerted by the muscles then transfers to the fins, which provide a platform to exert the thrust on the water. As the tail completes a whole "stroke" the forces shown above all cancel out. For the fish to swim, the thrust by the fish must be greater than the drag force of the water. Fish are made up of over 80% muscle to account for the amount of thrust in a heavy medium such as water.
http://www.lets-evo.net/2008/10/
Fins located on a fish body are used to keep the fish from flipping over and help it steer in the correct directions. The fins on the sides of their bodies are used to balance, while the ones located on the top and bottom of their bodies are used primarily for steering and keeping the fish from rolling over.
Return To Main Go To Jellyfish Eels Dolphins
A fishes fins and tail also play a major part in their movement and velocity through the water. When water flows past the fish, the energy exerted by the muscles then transfers to the fins, which provide a platform to exert the thrust on the water. As the tail completes a whole "stroke" the forces shown above all cancel out. For the fish to swim, the thrust by the fish must be greater than the drag force of the water. Fish are made up of over 80% muscle to account for the amount of thrust in a heavy medium such as water.
http://www.lets-evo.net/2008/10/
Fins located on a fish body are used to keep the fish from flipping over and help it steer in the correct directions. The fins on the sides of their bodies are used to balance, while the ones located on the top and bottom of their bodies are used primarily for steering and keeping the fish from rolling over.
Return To Main Go To Jellyfish Eels Dolphins