Common Bottlenose Dolphin - Tursiops truncatus
Common bottlenose dolphins are the most familiar dolphins due to the wide exposure they receive in captivity in marine parks and dolphinaria, and in movies and television programs. T. truncatus are the largest species of the beaked dolphins. They inhabit temperate and tropical oceans throughout the world, and are absent only from polar waters. All bottlenose dolphins were previously known as T. truncatus, but recently the genus has been split into two, T. truncatus and T. aduncus. Although this species has been traditionally called the bottlenose dolphin, many authors have used the name common bottlenose dolphin for this species since a second bottlenose dolphins species, the Indo-Pacific bottlenose dolphin, was described. The dolphins inhabit warm and temperate seas worldwide. Considerable genetic variation has been described among members of this species, even between neighboring populations, and so many experts believe that there may be multiple species included within T. truncatus. The common bottlenose dolphin is grey in color and may be between 2 and 4 metres (6.6 and 13 ft) long, and weigh between 150 and 650 kilograms (330 and 1,400 lb). Males are generally larger and heavier than females. In most parts of the world the adult's length is between 2.5 and 3.5 metres (8.2 and 11 ft) with weight ranges between 200 and 500 kilograms (440 and 1,100 lb). Newborn calves are between 0.8 and 1.4 meters long and weigh between 15 and 30 kilograms. The dolphins have a short and well-defined snout, that looks like an old-fashioned gin bottle, which is the source for their common name. Like all whales and dolphins, though, the snout is not a functional nose, which has evolved instead into the blowhole on the top of their head. Their neck is more flexible than other dolphins' due to 5 of their 7 vertebrae not being fused together as is seen in other dolphin species.
Leopard Seal - Hydrurga leptonyx
The leopard seal (Hydrurga leptonyx), also referred to as the sea leopard, is the second largest species of seal in the Antarctic (after the southern elephant seal). It is most common in the southern hemisphere along the coast of Antarctica and on most sub-Antarctic islands, but can also be found on the coasts of southern Australia, Tasmania, South Africa, New Zealand, Lord Howe Island, Tierra del Fuego, the Cook Islands, and the Atlantic coast of South America. It can live twenty-six years, possibly more. Orcas and large sharks are the only natural predators of leopard seals. The leopard seal is large and muscular, with a dark grey back and light grey on its stomach. Its throat is whitish with the black spots that give the seal its common name. Females are slightly larger than the males. The overall length of this seal is 2.4-3.5 m (7.9-11.7 ft) and weight is from 200 to 600 kilograms (440 to 1,300 lb). They are about the same length as the northern walrus but usually less than half the weight. Its front teeth are sharp like those of other carnivores, but its molars lock together in a way that allows them to sieve krill from the water, in the manner of the crabeater seal.The leopard seal is second only to the orca among Antarctica's top predators. Its canine teeth are 2.5 cm (1 in). It feeds on a wide variety of creatures. Smaller seals probably eat mostly krill, but also squid and fish. Larger leopard seals probably switch from krill to more substantial prey, including king, adelie, rockhopper, gentoo and emperor penguins, and less frequently, other seals such as the crabeater seal.