18-pound tortoise reportedly stolen from Iowa museum DUBUQUE, Iowa - A museum in Iowa says someone has stolen an 18-pound African leopard tortoise. Staff at the National Mississippi River Museum & Aquarium in Dubuque discovered the tortoise named Cashew was missing Tuesday. The staff believes Cashew was taken between Sunday afternoon and Monday night. Museum officials are reviewing security tapes in the hopes of identifying a suspect. Cashew was held in an enclosure that also had other tortoises. A museum official says the only way Cashew could get out was by someone climbing over a 4-foot glass wall and taking the animal. Officials believe the tortoise was taken as a prank or to sell it. Cashew has special dietary needs, but the museum won't specify those details in the hopes the thief will return the animal.