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.
The king penguin (Aptenodytes patagonicus) is a large species of penguin, second only to the emperor penguin in size. There are two subspecies: A. p. patagonicus and A. p. halli; patagonicus is found in the South Atlantic and halli elsewhere. King penguins eat small fish, mainly lanternfish, and squid. They are less reliant on krill and other crustaceans than most Southern Ocean predators. On foraging trips king penguins repeatedly dive to over 100 metres (300 ft), and have been recorded at depths greater than 300 metres (1,000 ft).