Respiratory+System

__Respiratory System __   //Varanus// lizards, in particular the //Varanus varius// (lace monitor), have evolutionarily developed a unique gaseous exchange pulmonary system that allows these reptiles to effectively transmit oxygen throughout their body during times of both rest and activity in order to survive in the Australian environment. They are among the only reptiles to have a spectrum (membrane) in place of a mammal’s diaphragm to separate the abdominal and chest cavity. The lungs contain an enlarged surface area due to their immense size in comparison to their body and therefore can extract larger amounts of oxygen from the air (Green, B. & King, D., 1993). This is helpful when in times of danger and pursuit and in times where large oxygen intake improve the lizards with an added evolutionary advantage.  __Mulitcameral lungs__ Multicameral lungs which are attached to the body wall to prevent collapse with large air intake allow //Varanus// lizards to alter between high and low activity levels and oxygen consumption (Green, B. & King, D., 1993). The development of a multicameral or mulit-chambered lung system has allowed //Varanus// species such as the //V. varius//to excel in their habitat of the eastern Australian environment (James, C. 1996). Encompassing a combination between __aerobic (oxygen)__ and __anaerobic (no oxygen)__ respiration systems has allowed //Varanus// lizards to control the amount of lactic acid present in their body (Knox, //et al.//, 2010) (Green, B. & King, D., 1993). Various literature articles stress the importance of having a low amount of lactic acid present in the body (Knox, 2010). Lactic acid build up within muscles is a result of long term use of anaerobic respiration methods and prevents sustained activity, thus causing muscle impediment and reduced mobility (Knox, //et al.//, 2010). Although the lace monitor is a predator in its environment a failure of basic mobility can have detrimental effects. Morphological adaptations allow lace monitors to survive in harsh seasonal change and drought conditions and this lizard is one of only few species in the world that seems highly tolerant to environmental climate change (Cronin, L., 2001).