image: This is an American water shrew hunting underwater for an insect larva. Weighing just 16 grams, American water shrews are the smallest mammalian divers and able to submerge for 24 seconds. Air trapped in their fur gives these fast and agile divers the appearance of a silver bullet. This image relates to a paper that appeared in the June 14, 2013, issue of Science, published by AAAS. The paper, by Scott Mirceta at University of Liverpool in Liverpool, UK, and colleagues was titled, "Evolution of Mammalian Diving Capacity Traced by Myoglobin Net Surface Charge." view more
Credit: [Image courtesy of Robert A. MacArthur/Kevin L. Campbell]