The green sea turtle (Chelonia mydas), also known as the green turtle, black (sea) turtle, or Pacific green turtle, is a large sea turtle of the family Cheloniidae. It is the only species in the genus Chelonia. Its range extends throughout tropical and subtropical seas around the world, with two distinct populations in the Atlantic and Pacific Oceans. The common name comes from the usually green fat found beneath its carapace.
Showing posts with label Underwater. Show all posts
Showing posts with label Underwater. Show all posts
Saturday, 8 March 2014
Thursday, 27 February 2014
Penguins
Penguins (order Sphenisciformes, family Spheniscidae) are a group of aquatic, flightless birds living almost exclusively in the Southern Hemisphere, especially in Antarctica. Highly adapted for life in the water, penguins have countershaded dark and white plumage, and their wings have evolved into flippers. Most penguins feed on krill, fish, squid and other forms of sealife caught while swimming underwater. They spend about half of their lives on land and half in the oceans.
Saturday, 22 February 2014
Starfish
Starfish are among the most familiar of marine invertebrates.
They typically have a central disc and five arms, though some species
have more than this. The aboral or upper surface may be smooth, granular
or spiny, and is covered with overlapping plates. Many species are
brightly coloured in various shades of red or orange, while others are
blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surface. They are opportunistic feeders and are mostly predators on benthic invertebrates. Several species having specialized feeding behaviours including eversion of their stomachs and suspension feeding.
They have complex life cycles and can reproduce both sexually and asexually. Most can regenerate damaged parts or lost arms and they can shed arms as a means of defence. The Asteroidea occupy several significant ecological roles. Starfish, such as the ochre sea star (Pisaster ochraceus) and the reef sea star (Stichaster australis), have become widely known as examples of the keystone species concept in ecology. The tropical crown-of-thorns starfish (Acanthaster planci) is a voracious predator of coral throughout the Indo-Pacific region, and the northern Pacific sea star is considered to be one of the world's 100 worst invasive species.
Wednesday, 19 February 2014
Lion Fish
Pterois, commonly known as lionfish, is a genus of venomous marine fish found mostly in the Indo-Pacific. Pterois is characterized by conspicuous warning coloration with red, white, creamy, or black bands, showy pectoral fins and venomous spiky fin rays. Pterois are classified into a number of different species, but Pterois radiata, Pterois volitans and Pterois miles are the most commonly studied. Pterois are popular aquarium fish.
Beluga Whale
The beluga or white whale, Delphinapterus leucas, is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus Delphinapterus. This marine mammal is commonly referred to simply as the melonhead, beluga or sea canary due to its high-pitched twitter.
It is adapted to life in the Arctic, so has a number of anatomical and physiological
characteristics that differentiate it from other cetaceans. Amongst
these are its unmistakable all-white colour and the absence of a dorsal
fin. It possesses a distinctive protuberance at the front of its head
which houses an echolocation organ called the melon, which in this species is large and plastic
(deformable). The beluga’s body size is between that of a dolphin’s and
a true whale’s, with males growing up to 5.5 m (18 ft) long and
weighing up to 1,600 kg (3,500 lb). This whale has a stocky body; it has
the greatest percentage of blubber. Its sense of hearing is highly
developed and it possesses echolocation, which allows it to move about and find blowholes under sheet ice.
Tuesday, 18 February 2014
Octopus
Enteroctopus is a genus of generally temperate octopuses. Members of the genus Enteroctopus are characterized by their large size and are often known as the giant octopuses. Enteroctopus
species have distinct longitudinal wrinkles or folds dorsally and
laterally on the body. The head is distinctly narrower than the mantle
width. The hectocotylus of the males in this genus, found on the third right arm, is long and narrow in comparison with other genera in the family Octopodidae, often comprising one fifth the length of the arm. Octopuses in this genus have large paddle-like papillae instead of the more conical papillae in other octopus genera
Monday, 17 February 2014
Penguins
The largest living species is the Emperor Penguin (Aptenodytes forsteri): on average adults are about 1.1 m (3 ft 7 in) tall and weigh 35 kg (75 lb) or more. The smallest penguin species is the Little Blue Penguin (Eudyptula minor),
also known as the Fairy Penguin, which stands around 40 cm tall (16 in)
and weighs 1 kg (2.2 lb). Among extant penguins, larger penguins
inhabit colder regions, while smaller penguins are generally found in
temperate or even tropical climates (see also Bergmann's Rule). Some prehistoric
species attained enormous sizes, becoming as tall or as heavy as an
adult human. These were not restricted to Antarctic regions; on the
contrary, subantarctic regions harboured high diversity, and at least one giant penguin occurred in a region not quite 2,000 km south of the equator 35 mya, in a climate decidedly warmer than today.
Thursday, 13 February 2014
Sea Turtle
Sea turtles, along with other turtles and tortoises, are part of the order Testudines.
The seven living species of sea turtles are: flatback sea turtle, green sea turtle, hawksbill sea turtle, Kemp's ridley sea turtle, leatherback sea turtle, loggerhead sea turtle and olive ridley sea turtle.
All species except the leatherback are in the family Cheloniidae.
The
leatherback belongs to the family Dermochelyidae and is its only member.The species are primarily distinguished by their anatomy: for
instance, the prefrontal scales on the head, the number of and shape of scutes on the carapace, and the type of inframarginal scutes on the plastron. The leatherback
is the only sea turtle that does not have a hard shell; instead, it
bears a mosaic of bony plates beneath its leathery skin. It is the
largest sea turtle, measuring 6 to 7 feet (1.8 to 2.1 m) in length at
maturity, and 3 to 5 feet (0.91 to 1.52 m) in width, weighing up to
1,300 pounds (590 kg). Other species are smaller, being mostly 2 to 4
feet (0.61 to 1.22 m) and proportionally narrower
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