Oxygen Capacity of Lizard Bloods

摘要: The oxygen capacity of bloods from nineteen species lizards representing eight genera and three families were determined. Mean values obtained for these ranged 7.7 to 12.6 vol %. Oxygen was found be uncorrelated with the extent heat resistance characterizing various species. Likewise no correlation evident between altitude at which had existed prior study, whether analysis concerned populations within a single (Sceloporus jarrovi), genus (Sceloporus), or entire array studied. reported this study fall t'he general range previously established reptiles by other authors. upper portion overlaps lower that capacities birds mammals. This overlap suggests demands upon respiratory transport created intensification metabolism in evolution homeothermy have been met primarily through such means as augmentation cardiac output rather than any major increase blood. We undertaken lizard an initial step group. Bloods southwestern United States, analyzed. Acknowledgments. -We are extremely grateful Dr. Mont A. Cazier, Director Southwestern Research Station, numerous courtesies extended us during our work Arizona, Harvey F. Pough assistance rendered capture maintenance lizards. also wish thank Wilbur W. Mayhew University Calilfornia Riverside supplying desert iguanas, Dipsosaurus dorsalis. supported part grants National Science Foundation (G-2096 G-9238) Horace H. Rackham School Graduate Studies, Michigan. MATERIALS AND METHODS A majority used extreme southeastern Arizona New Mexico, 25 miles near Portal, Arizona. Sceloporus poinsetti Crotaphytus collaris Hidalgo County, Mexico. jarrovi, S. undulatus virgatus (designation subspecies has made only where two more conspecific forms occur same county), clarki, Uta stansburiana, Holbrookia texana, Phrynosoma modestum, P. cornutum, douglassi, Cnemidophorus inornatus, C. sacki, tigris, Cochise Lizards could approached closely captured noose connected end trout pole. More wary animals stunning them heavy rubber band Present address: Department Zoology, Yale University.