Swim/Gas Bladder

  • The swim bladder on the longnose gar can function much like the swim bladder in any number of fishes. It is meant to hold a specific amount of air so the fish can remain at a particular depth due to the bouncy of the air. This is a very helpful feature because the fish does not have to waste energy by constantly having to swim to adjust it depth. Though this is swim bladder is found in a wide variety of fish the longnose gar has another use for its swim bladder. The longnose gar has found a way in which it can use its swim bladder as a primitive lung to breathe atmospheric air. This very specialized ability is due to the unique way in which the longnose gar’s swim bladder is built. For starters the swim bladder is attached to the gars esophagus which allows the fish to inhale and exhale easily through its mouth. The swim bladder also contains a rough surface on the inner wall of the bladder allowing for the transfer of gasses into and out of the fishes blood stream (Zaccone, Sengar & Lauriano, 2012). The gar’s swim bladder is advanced enough to allow the gar to survive on only atmospheric air when water oxygen levels are low (Rudy, 2003).


  • The longnose gar possesses scales that are able to protect the animal from a variety of different attackers. The genes name for longnose gar is Lepisosteus which in Greek translates to Scale (Lepis), and bone (Osteos). It earned this name because of the very tough scales which are composed of ganoin, an enamel type substance that gives the scale a very hard shell (Rudy, 2003). The scales are specially designed to interlock and create a type of armor suite covering the fish. These scales in addition to protection provide a hydrodynamic surface that the gar can use to move through the water easier (Long, Hale, Mchenry & Westneat, 1996).


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