Atrial fibrillation (AF or A-fib) is an abnormal heart rhythm characterized by rapid and irregular beating.
Emperor penguins owe their scientific name (Aptenodytes forsteri) to their discoverer, the first natural scientist to reach Antarctica, the German Johann Reinhold Forster. Forster came to Antarctica in 1770, on Captain James Cook's ship, and saved Cook's life during the voyage.
Emperor penguins, Aptenodytes forsteri, feed on small pelagic (open water) fishes, crustaceans, and cephalopods. Adults and juveniles are preyed on by leopard seals, orca (killer whales), and sharks; chicks are preyed on by skua gulls (pictured above) and Antarctic giant petrels.