HECTOR'S DOLPHIN

HECTOR'S DOLPHIN

Hector's dolphin Cephalorhynchus hectori is the best-known of the four dolphins in the genus Cephalorhynchus and is found only in New Zealand. At approximately 1.4 m in length, it is one of the smallest cetaceans, and New Zealand's only endemic cetacean.
Two subspecies occur: C. h. hectori, the more numerous subspecies, is found around the South Island, and the critically endangered Maui's dolphin C. h. maui is found off the northwest coast of the North Island. Maui's dolphin is one of the eight most endangered groups of cetaceans. The Hector's dolphin is also the world's smallest and rarest dolphin. A 2010/2011 survey by the New Zealand Department of Conservation estimated only 55 adults remained.
Hector’s dolphin was named after Sir James Hector 1834–1907, who was the curator of the Colonial Museum in Wellington now the Museum of New Zealand Te Papa Tongarewa. He examined the first specimen found of the dolphin. The species was scientifically described by Belgian zoologist Pierre-Joseph van Beneden in 1881.

BLACK RHINOCEROS

BLACK RHINOCEROS

The black rhinoceros or hook-lipped rhinoceros Diceros bicornis is a species of rhinoceros, native to eastern and central Africa including Kenya, Tanzania, Cameroon, South Africa, Namibia, Zimbabwe, and Angola. Although the rhinoceros is referred to as black, its colors vary from brown to grey.
The other African rhinoceros is the white rhinoceros Ceratotherium simum. The word "white" in the name "white rhinoceros" is a misinterpretation of the Afrikaans word wyd, itself derived from the Dutch word wijd for wide, referring to its square upper lip, as opposed to the pointed or hooked lip of the black rhinoceros. These species are now sometimes referred to as the square-lipped for white or hook-lipped for black rhinoceros.
The species overall is classified as critically endangered, and one subspecies, the western black rhinoceros, was declared extinct by the IUCN in 2011.

NARWHAL

The narwhal, or narwhal, is a medium-sized toothed whale and possesses a large "tusk" from a protruding canine tooth. It lives year-round in the Arctic waters around Greenland, Canada, and Russia. It is one of two living species of whale in the Monodontidae family, along with the beluga whale. The narwhal males are distinguished by a long, straight, helical tusk, which is an elongated upper left canine. The narwhal was one of many species described by Carolus Linnaeus in his publication Systema Naturae in 1758.
Like the beluga, narwhals are medium-sized whales. For both sexes, excluding the male's tusk, the total body size can range from 3.95 to 5.5 metres 13.0 to 18.0 feet; the males are slightly larger than the females. The average weight of an adult narwhal is 800 to 1,600 kilograms 1,800 to 3,500 pounds. At around 11 to 13 years old, the males become sexually mature; females become sexually mature at about 5 to 8 years old. Narwhals do not have a dorsal fin, and their neck vertebrae are jointed like those of other mammals, not fused as in dolphins and most whales. Narwhals can live up to 50 years old. They are often killed by suffocation when the sea ice freezes over. Another cause of fatality, specifically among young whales, is starvation. 

BLUE FIN TUNA

BLUE FIN TUNA
The blue fin tuna is a predatory species of tuna found widely in the northern Pacific Ocean, but it is migratory and also recorded as a visitor to the south Pacific.In the past it was often included, the 'combined' species then known as the northern blue fin tuna . It may reach as much as 3 m (9.8 ft) in length and 450 kg (990 lb) in weight.
Most fish are cold-blooded. However, tuna and mackerel sharks are warm-blooded: they can regulate their body temperature. Warm-blooded fish possess organs near their muscles called retia mirabilia that consist of a series of minute parallel veins and arteries that supply and drain the muscles. As the warmer blood in the veins returns to the gills for fresh oxygen it comes into close contact with cold, newly oxygenated blood in the arteries. The system acts as a counter-current heat exchanger and the heat from the blood in the veins is given up to the colder arterial blood rather than being lost at the gills. The net effect is less heat loss through the gills. Fish from warmer water elevate their temperature a few degrees whereas those from cold water may raise it as much as 20 °C warmer than the surrounding sea.
The tuna's ability to maintain body temperature has several definite advantages over other sea life. It need not limit its range according to water temperature, nor is it dominated by climatic changes. The additional heat supplied to the muscles is also advantageous because of the resulting extra power and speed. Bluefin tuna have been clocked in excess of 30 miles per hour during 10 to 20 second sprints, enabling it to hunt squid, herring, mackerel, etc., that slower predators cannot captur

LEATHER BACK TURTLE

LEATHER BACK TURTLE
The leatherback sea turtle, sometimes called the lute turtle or leathery turtle, is the largest of all living turtles and is the fourth-heaviest modern reptile behind three crocodiles. It is the only living species in the genus Dermochelys. It can easily be differentiated from other modern sea turtles by its lack of a bony shell. Instead, its carapace is covered by skin and oily flesh. D. coriacea is the only extant member of the family Dermochelyidae.
Relatives of modern leatherback turtles have existed in some form since the first true sea turtles evolved over 110 million years ago during the Cretaceous period. The dermochelyids are close relatives of the family Cheloniidae, which contains the other six extant sea turtle species. However, their sister taxon is the extinct family Protostegidae which included other species not having a hard carapace.
Leatherback turtles have the most hydrodynamic body design of any sea turtle, with a large, teardrop-shaped body. A large pair of front flippers power the turtles through the water. Like other sea turtles, the leatherback has flattened fore limbs adapted for swimming in the open ocean. Claws are absent from both pairs of flippers. The leatherback's flippers are the largest in proportion to its body among extant sea turtles. Leatherback's front flippers can grow up to 2.7 m in large specimens, the largest flippers of any sea turtle.
Leatherback turtles are one of the deepest-diving marine animals. Individuals have been recorded diving to depths as great as 1,280 m. Typical dive durations are between 3 and 8 minutes, with dives of 30–70 minutes occurring infrequently.

WHALE

WHALE

Whale origin Old English hwæl from Proto-Germanic hwalaz is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to the suborder Odontoceti toothed whales. This suborder includes the sperm whale, killer whale, pilot whale, and beluga whale. The other cetacean suborder, Mysticeti baleen whales, comprises filter feeders who eat small organisms caught by straining seawater through a comblike structure found in the mouth called baleen. This suborder includes the blue whale, the humpback whale, the bowhead whale and the minke whale. All cetaceans have forelimbs modified as fins, a tail with horizontal flukes, and nasal openings blowholes on top of the head.
Whales range in size from the blue whale, the largest animal known to have ever existed, at 30 m 98 ft and 180 tonnes 180 long tons; 200 short tons, to pygmy species such as the pygmy sperm whale at 3.5 m 11 ft. Whales inhabit all the world's oceans and number in the millions, with annual population growth rate estimates for various species ranging from 3% to 13%. Whales are long-lived, humpback whales living for up to 77 years, while bowhead whales may live for more than a century.
Human hunting of whales from the seventeenth century until 1986 radically reduced the populations of some whale species.
Whales play a role in creation myths, for example among the Inuit, and they are revered by coastal people in countries such as Ghana and Vietnam.

OLIVE RIDLEY TURTLE

OLIVE RIDLEY TURTLE
The olive ridley sea turtle, also known as the Pacific ridley sea turtle, is a medium-sized species of sea turtle found in warm and tropical waters, primarily in the Pacific and Indian Oceans.
The olive ridley is a small sea turtle, with an adult carapace length averaging 60 to 70 cm.[3] The heart-shaped carapace is characterized by four pairs of pore-bearing inframarginal scutes on the bridge, two pairs of prefrontals, and up to 9 lateral scutes per side. Olive ridleys are unique in that they can have variable and asymmetrical lateral scute 6 to 8 counts ranging from five to 9 plates on each side, with six to eight being most commonly observed.[3] Each side of the carapace has 12–14 marginal scutes. The carapace is flattened dorsally and highest anterior to the bridge.
It has a medium–sized, broad head that appears triangular from above. The head's concave sides are most obvious on the upper part of the short snout. It has paddle-like forelimbs, each having two anterior claws. The upperparts are grayish green to olive in color, but sometimes appear reddish due to algae growing on the carapace. The bridge and hingeless plastron of an adult varies from greenish white in younger individuals to a creamy yellow in older specimens.
Hatchlings are dark gray with a pale yolk scar, but appear all black when wet.^[3] Carapace length ranges from 37 to 50 mm. A thin, white line borders the carapace, as well as the trailing edge of the fore and hind flippers.^[4] Both hatchlings and juveniles have serrated posterior marginal scutes, which become smooth with age. Juveniles also have three dorsal keels; the central longitudinal keel gives younger turtles a serrated profile, which remains until sexual maturity is reached