The Galapagos Giant Tortoise (Geochelone elephantopus) weigh as much as 550 pounds and can live for over 200 years.  It is quite possible that some of the tortoises Charles Darwin saw 161 years ago may still be alive today.  Then there were an estimated 250,000 tortoises and 14 varieties.  Today only 15,000 remain and three varieties are extinct altogether and a fourth variety has only one remaining member (Lonesome George).  They are vegetarian, eating large quantities of prickly pear, cactus and fruits, bromeliads, water ferns, the so-called poison apple, and other native species.  The Giant Tortoise can survive many months without food or water which enable them to survive the long arid season.