Tuesday, November 6, 2007

Top 10 Ugliest Animals

10. Mata Mata

The mata mata is a freshwater turtle found predominantly in South America, notably in the Amazon and Orinoco basins. The animal’s peculiar physical aspect distinguishes it from other members of its order. It is an animal highly skilled in hunting techniques.

9. Horseshoe Bat

Horseshoe bats (the Rhinolophidae family) are a large family of bats including approximately 130 species grouped in 10 genera. All rhinolophids have leaf-like protuberances on their noses. In rhinolophines species, these take the shape of a horseshoe; in hipposiderine, they are leaf- or spear-like. They emit echolocation calls through these structures, which may serve to focus the sound. Most rhinolophids are dull brown or reddish brown in color. They vary in size from small to moderately large.

8. Star Nosed Mole

The Star-nosed Mole is a small North American mole found in eastern Canada and the north-eastern United States. It lives in wet lowland areas and eats small invertebrates, aquatic insects, worms and molluscs. It is a good swimmer and can forage along the bottoms of streams and ponds. Like other moles, this animal digs shallow surface tunnels for foraging; often, these tunnels exit underwater. It is active day and night and remains active in winter, when it has been observed tunnelling through the snow and swimming in ice-covered streams.

7. Sloth

Sloths are medium-sized mammals that live in Central and South America. Sloths are omnivores. They may eat insects, small lizards and carrion, but their diet consists mostly of buds, tender shoots, and leaves. Sloth fur also exhibits specialized functions: the outer hairs grow in a direction opposite from that of other mammals. In most mammals, hairs grow toward the extremities, but because sloths spend so much time with their legs above their bodies, their hairs grow away from the extremities in order to provide protection from the elements while the sloth hangs upside down.

6. Naked Mole Rat

The Naked Mole Rat, also known as the Sand Puppy, or Desert Mole Rat, is a burrowing rodent native to parts of East Africa. Typical individuals are 8–10 cm long and weigh 30–35 g. Queens are larger and may weigh well over 50 g, the largest reaching 80 g. They are well-adapted for their underground existence. Their eyes are just narrow slits, and consequently their eyesight is poor. However, they are highly adapted to moving underground, and can move backwards as fast as they move forwards. Their large, protruding teeth are used to dig. Their lips are sealed just behind their teeth while digging to avoid filling their mouths with soil. Their legs are thin and short. They have little hair (hence the common name) and wrinkled pink or yellowish skin.

5. Axolotl

The Axolotl (or ajolote) is the best-known of the Mexican neotenic mole salamanders belonging to the Tiger Salamander complex. Larvae of this species fail to undergo metamorphosis, so the adults remain aquatic and gilled. Their heads are wide, and their eyes are lidless. Their limbs are underdeveloped and possess long, thin digits. Axolotls have barely visible vestigial teeth which would have developed during metamorphosis. The primary method of feeding is by suction, during which their rakers interlock to close the gill slits. Axolotls have 4 different colours, 2 naturally occurring colours and 2 mutants. The 2 naturally occurring colours are wildtype (Varying shades of brown usually with spots) and melanoid (black). The 2 mutants colours are leucistic (pale pink with black eyes) and albino (golden, tan or pale pink with pink eyes).

4. Tarsier

Tarsiers are prosimian primates of the genus Tarsius. Tarsiers have enormous eyes and long feet. Their feet have extremely elongated tarsus bones, which is how they got their name. They are primarily insectivorous, and catch insects by jumping at them. They are also known to prey on birds and snakes. As they jump from tree to tree, tarsiers can catch even birds in motion. Tarsiers have never formed successful breeding colonies in captivity, and when caged, tarsiers have been known to injure and even kill themselves because of the stress.

3. Hagfish

Despite their name, there is some debate about whether Hagfish are strictly fish, since they belong to a much more primitive lineage than any other group that is commonly defined fish. Hagfish are long, vermiform and can exude copious quantities of a sticky slime or mucus. When captured and held by the tail, they escape by secreting the fibrous slime, which turns into a thick and sticky gel when combined with water, and then cleaning off by tying themselves in an overhand knot which works its way from the head to the tail of the animal, scraping off the slime as it goes. Hagfish have elongated, ‘eel-like’ bodies, and paddle-like tails.

2. Aye-aye

The Aye-aye is a native to Madagascar that combines rodent-like teeth with a long, thin middle finger to fill the same ecological niche as a woodpecker. The Aye-aye is the world’s largest nocturnal primate, and dwells predominantly in forest canopies. The adult Aye-aye has black or dark brown fur covered by white guard hairs at the neck. The tail is bushy and shaped like that of a squirrel. The Aye-aye’s face is also rodent-like, the shape of a raccoon’s, and houses bright, beady, luminous eyes. Its incisors are very large, and grow continuously throughout its lifespan.

1. Blobfish

The Blobfish inhabits the deep waters off the coasts of Australia and Tasmania. Due to the inaccessibility of its habitat, it’s rarely seen by humans. Blobfish are found at depths where the pressure is several dozens of times higher than at sea level. To remain buoyant, the flesh of the Blobfish is primarily a gelatinous mass with a density slightly less than water; which allows the fish to float above the sea floor without expending energy on swimming. The relative lack of muscle is not a disadvantage as it primarily swallows edible matter that floats by in front it.

Friday, November 2, 2007

Top 10 Strangest Animals

10. Frill-necked Lizard

The Frill-necked Lizard, also known as the Frilled Dragon, is so called because of the large ruff of skin which usually lies folded back against its head and neck. Long spines of cartilage support the neck frill, and when the lizard is frightened, it opens its mouth showing a bright pink or yellow lining, and the frill flares out, displaying bright orange and red scales. They often walk on four legs when on the ground. When frightened they begin to run on all fours and then accelerate onto the hind-legs. The frill of the Australian frilled dragon is used to frighten off potential predators, as well as hissing and lunging.

9. Dumbo Octopus

The octopuses of the genus Grimpoteuthis are also known as “Dumbo octopuses” from the ear-like fins protruding from the top of their “heads” (actually bodies), resembling the ears of Walt Disney’s flying elephant. They are benthic creatures, living at extreme depths, and are some of the rarest of the Octopoda species. They can flush the transparent layer of their skin at will, and are open ocean animals, unlike most octopi.

8. Angora Rabbit

The Angora rabbit is a variety of domestic rabbit bred for its long, soft hair. The rabbits were popular pets with French royalty in the mid 1700s, and spread to other parts of Europe by the end of the century. They are bred largely for their long wool, which may be removed by shearing or plucking (gently pulling loose wool).

7. Tasmanian Tiger

The Thylacine was the largest known carniv

orous marsupial of modern times. Native to Australia and New Guinea, it is thought to have become extinct in the 20th century. It is commonly known as the Tasmanian Tiger (due to its striped back), the Tasmanian Wolf, and colloquially the Tassie (or Tazzy) Tiger. It was the last extant member of its genus, Thylacinus, although a number of related species have been found in the fossil record dating back to the early Miocene. The Thylacine became extinct on the Australian mainland thousands of years before European settlement of the continent, but survived on the island of Tasmania along with a number of other endemic species, including the Tasmanian Devil. Intensive hunting encouraged by bounties is generally blamed for its extinction, but other contributory factors may have been disease, the introduction of dogs, and human encroachment into its habitat. Despite being officially classified as extinct, sightings are still reported.

6. Platypus

The Platypus is a semi-aquatic mammal endemic to eastern Australia. Together with the four species of echidna, it is one of the five mammals that lay eggs instead of giving birth to live young. The bizarre appearance of this egg-laying, duck-billed mammal baffled naturalists when it was first discovered, with some considering it an elaborate fraud. It is one of the few venomous mammals; the male Platypus has a spur on the hind foot, which delivers a poison capable of causing severe pain to humans. The unique features of the Platypus make it an important subject in the study of evolutionary biology and a recognizable and iconic symbol of Australia; it has appeared as a mascot at national events and is featured on the reverse of the Australian 20 cent coin.

5. Narwhal

The Narwhal is an Arctic species of cetacean. It is one of two species of white whale, the other being the Beluga whale. The most conspicuous characteristic of male narwhal is their single extraordinarily long tusk, an incisor that projects from the left side of the upper jaw and forms a left-handed helix. The tusk can be up to nearly 10 feet long and weigh up to 22 pounds. About one in 500 males has two tusks, which occurs when the right tooth, normally small, also grows out. The purpose of the tusk has been the subject of much debate. Early scientific theories suggested that the tusk was used to pierce the ice covering the narwhal’s Arctic Sea habitat. Others suggested the tusk was used in echolocation. More recently, scientists believed the tusk is primarily used for showmanship and for dominance: males with larger tusks are more likely to successfully attract a mate.

4. Anglerfish

Anglerfish are named for their characteristic mode of perdition, wherein a fleshy growth from the fish’s head (the esca) acts as a lure. Anglerfish also have spines protruding from their head, movable in all directions. The esca can be wiggled so as to resemble a prey animal, and thus to act as bait to lure other predators. Deep-sea anglerfish live mainly in the oceans’ aphotic zones, where the water is to deep for the sun to penetrate; therefore their perdition relies on the “lure” being bioluminescent. Since individuals are presumably locally rare and encounters doubly so, finding a mate is problematic. When scientists first started capturing ceratioid anglerfish, they noticed that all of the specimens were females. These individuals were a few inches in size and almost all of them had what appeared to be parasites attached to them. It turned out that these “parasites” were the remains of male ceratioids

3. Leafy Sea-dragon

Named after the dragons of Chinese mythology, Leafy Sea-dragons resemble a piece of drifting seaweed as they float in the seaweed-filled water. The Leafy Sea-dragon, with green, orange and gold hues along its body, is covered with leaf-like appendages, making it remarkably camouflaged. Only the fluttering of tiny fins or the moving of an independently swiveling eye reveals its presence. Sea-dragons have no teeth or stomach and feed exclusively on mysidopsis shrimp. Known as “Australian seahorses” in Australia, they are found in calm, cold water that is approximately 50-54° Fahrenheit. The South Australian government since 1982 has protected Leafy Sea-dragons.

2. Yeti Crab

Kiwa hirsuta is a crustacean discovered in 2005 in the South Pacific Ocean. This decapod, 6 inches long, is notable for the quantity of silky blond setae (resembling fur) covering thoracic legs and claws. Its discoverers dubbed it the “yeti lobster” or “yeti crab”. Based on both morphology and molecular data, the species was deemed to form a new genus and family (Kiwaidae). The animal has strongly reduced eyes that lack pigment, and is thought to be blind. The ‘hairy’ pincers contain filamentous bacteria, which the creature may use to detoxify poisonous minerals from the water emitted by the hydrothermal vents where it lives. Alternatively, it may feed on the bacteria, although it is thought to be a general carnivore. Its diet also consists of green algae and small shrimp.

1. Coelacanth

Coelacanth is the common name for an order of fish that includes the oldest living lineage of jawed fish known to date. The coelacanths, which are related to lungfishes and tetrapods, were believed to have been extinct since the end of the Cretaceous period, until the first specimen was found off the east coast of South Africa, off the Chalumna River in 1938. Since 1938, they have been found in the Comoros, Kenya, Tanzania, Mozambique, Madagascar, among other places. Coelacanths first appear in the fossil record in the Middle Devonian, about 410 million years ago. Coelacanths are lobe-finned fish with the pectoral and anal fins on fleshy stalks supported by bones, and the tail or caudal fin diphycercal (divided into three lobes), the middle one of which also includes a continuation of the notochord.