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About video

Foil shaped fins generate thrust when moved, the lift of the fin sets water or air in motion and pushes the fin in the opposite direction. Aquatic animals get significant thrust by moving fins back and forth in water. Often the tail fin is used, but some aquatic animals generate thrust from pectoral fins. Fins are one of the most distinguishing features of a fish and they have several different forms. Two types of fins are found in most of the fish median and paired fins. Median fins are single in number which runs down the mid-line of the body. The vertebrate jaw probably originally evolved in the silurian period and appeared in the placoderm fish which further diversified in the devonian. Jaws are thought to derive from the pharyngeal arches that support the gills in fish. The two most anterior of these arches are thought to have become the jaw itself (see hyomandibula) and the hyoid arch, which braces the jaw against the braincase and increases mechanical efficiency. Locomotory organs of fish - fins fins are locomotory organs of fishes that propel, steer and turn the body in water which is a viscous medium when compared to terrestrial situations. Fishes possess two pairs of paired fins, namely, pectoral and pelvic which are used for steering, braking, balancing and pitching. Caudal fin propels the body forward and also neutralizes drag against water. Dorsal fins above the fishs rolling axis, these lateral forces, if unchecked, would cause fish to roll. In this paper we examine the hydrodynamics of trout anal fin function and. The anal fin supports the dorsal fins by providing the fish with more stability in the water, controlling the rolling motion. Pectoral fin like the ailerons in an aircrafts wings, the pectoral fins located on either side of the fish, helps it turn left or right and also provides support while swimming. They tend to be positioned near the anal fin in the lower fish and placed below or a little behind the pectoral fins in the higher fish. The dorsal fin(s) may extend the length of the back, be divided into two or three separate fins, or be single and small. In some groups (salmonids and some catfish) there is a small, fleshy adipose dorsal fin.   dorsal and anal fins are median fins located above and below the centre of mass of fishes, each having a moment arm relative to the longitudinal axis. Understanding the kinematics of dorsal and anal fins may elucidate how these fins are used in concert to maintain and change fish body position and yet little is known about the functions of these fins. The fish uses this fin for balance in the water and sudden movements. For most fish, the dorsal fin keeps them from rolling over in the water (stability), and to help them make sudden turns. For other fish, such as a sunfish, they use their dorsal fin (and anal fin.).

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