Kangaroo

The word kangaroo derives from the Guugu Yimithirr word gangurru, referring to grey kangaroos. The name was first recorded as "Kangooroo or Kanguru" on 4 August 1770, by Lieutenant (later Captain) James Cook on the banks of the Endeavour River at the site of modern Cooktown, when HM Bark Endeavour was beached for almost seven weeks to repair damage sustained on the Great Barrier Reef. Guugu Yimithirr is the language of the people of the area.

A common myth about the kangaroo's English name is that "kangaroo" was a Guugu Yimithirr phrase for "I don't understand you." According to this legend, Lieutenant Cook and naturalist Sir Joseph Banks were exploring the area when they happened upon the animal. They asked a nearby local what the creatures were called. The local responded "Kangaroo", meaning "I don't understand you", which Cook took to be the name of the creature. The Kangaroo myth was debunked in the 1970s by linguist John B. Haviland in his research with the Guugu Yimithirr people.

Kangaroos are often colloquially referred to as roos. Male kangaroos are called bucks, boomers, jacks, or old men; females are does, flyers, or jills, and the young ones are joeys. The collective noun for kangaroos is a mob, troop, or court. Mobs usually have ten or more kangaroos in them. Living in mobs provides protection for some of the weaker members of the group.

Biology and behaviour

Kangaroos are the only large animals to use hopping as a means of locomotion. The comfortable hopping speed for Red Kangaroo is about 20–25 km/h (13–16 mph), but speeds of up to 70 km/h (44 mph) can be attained, over short distances, while it can sustain a speed of 40 km/h (25 mph) for nearly 2 kilometres (1.2 mi). This fast and energy-efficient method of travel has evolved because of the need to regularly cover large distances in search of food and water, rather than the need to escape predators.[citation needed] To move at slow speeds, it uses its tail to form a tripod with its two forelimbs it then raises its hind feet forward.

The average lifespan of kangaroos averages at 6 years in the wild to in excess of 20 years in captivity, varying by species. Most individuals, however, do not reach maturity in the wild.

Diet

Different species of kangaroos have different diets, although all are strict herbivores. The Eastern Grey Kangaroo is predominantly a grazer eating a wide variety of grasses whereas some other species (e.g. the Red Kangaroo) include significant amounts of shrubs in the diet. The smaller species of kangaroos also consume hypogeal fungi. Many species are nocturnal and crepuscular, usually spending the days resting in shade and the cool evenings, nights and mornings moving about and feeding.

Because of its grazing, kangaroos have developed specialised teeth. Its incisors are able to crop grass close to the ground, and its molars chop and grind the grass. Since the two sides of the lower jaw are not joined together, the lower incisors are farther apart, giving the kangaroo a wider bite. The silica in grass is abrasive, so kangaroo molars move forward as they are ground down, and eventually fall out, replaced by new teeth that grow in the back.

Blindness

Eye disease is rare but not new among kangaroos. The first official report of kangaroo blindness took place in 1994, in central New South Wales. The following year, reports of blind kangaroos appeared in Victoria and South Australia. By 1996, the disease had spread "across the desert to Western Australia".[citation needed] Australian authorities were concerned that the disease could spread to other livestock and possibly humans. Researchers at the Australian Animal Health Laboratories in Geelong detected a virus called the Wallal virus in two species of midge, believed to have been the carriers. Veterinarians also discovered that less than three percent of kangaroos exposed to the virus developed blindness.

American Bullfrog

Description
Bullfrogs grow on average to be about 3.5 to 6.0 inches (9–15 cm) in body length (although there are records of some up to 8.0 inches), legs add another 7–10 inches (17–25 cm) to length. The adult bullfrog skeleton is representative of tetrapod vertebrates, comprising an axial skeleton (skull and vertebrae) and an appendicular skeleton (pectoral girdle and forelimbs, pelvic girdle and hindlimbs). Ranids, however, lack ribs. The pronounced pair of dorsal humps in the back of ranid frogs are the ends of the pelvic ilia, homologues of the human hips.

Growth and development
Eggs hatch in three to five days. Time to metamorphosis ranges from a few months in the southern to three years in the northern parts of the geographic range.Maximum lifespan in the wild is estimated at eight to 10 years, but one captive lived almost 16 years.

Feeding
A juvenile with a small, grey, oval-shaped area on top of the head, the parietal eye
Native habitat

Stomach content studies going back to 1913 suggest the bullfrog preys on any animal it can overpower and stuff down its throat. Bullfrog stomachs have been found to contain rodents, small turtles, snakes, frogs (including bullfrogs), birds, and a bat, as well as the many invertebrates which are the usual food of ranid frogs. These studies furthermore reveal the bullfrog's diet to be unique among North American Rana in the inclusion of large percentages of aquatic animals, e.g., fish, tadpoles, planorbid snails, and dytiscid beetles. The specialized ability of bullfrogs to capture submerged and large, strong prey comprises a pronounced biting motor pattern that follows up on the initial and typical ranid tongue strike.Adaptation to target image displacement due to light refraction at the water-air interface consists of the bullfrog's application of tongue surface comparatively posterior to the perceived location of the prey target. The comparative ability of bullfrogs to capture submerged prey, compared to that of the green frog, leopard frog, and wood frog (R. clamitans, R. pipiens, R. sylvatica, respectively) was also demonstrated in laboratory experiments.

Whale shark

The whale shark, Rhincodon typus, is a slow-moving filter feeding shark, the largest living fish species. The largest confirmed individual was 12.65 metres (41.50 ft) in length and the heaviest weighed more than 36 tonnes (79,000 lb), but unconfirmed claims report considerably larger whale sharks. This distinctively-marked fish is the only member of its genus Rhincodon and its family, Rhincodontidae (called Rhinodontes before 1984), which belongs to the subclass Elasmobranchii in the class Chondrichthyes. The shark is found in tropical and warm oceans, lives in the open sea with a lifespan of about 70 years. The species originated about 60 million years ago. Although whale sharks have very large mouths, they feed mainly, though not exclusively, on plankton, microscopic plants and animals. However, the BBC program Planet Earth filmed a whale shark feeding on a school of small fish.

Description

As a filter feeder it has a capacious mouth which can be up to 1.5 metres (4.9 ft) wide and can contain between 300 and 350 rows of tiny teeth. It has five large pairs of gills. Two small eyes are located towards the front of the shark's wide, flat head. The body is mostly grey with a white belly; three prominent ridges run along each side of the animal and the skin is marked with a "checkerboard" of pale yellow spots and stripes. These spots are unique to each individual and are useful for counting populations. Its skin can be up to 10 centimetres (3.9 in) thick. The shark has a pair each of dorsal fins and pectoral fins.

Diet

The whale shark is a filter feeder — one of only three known filter feeding shark species (along with the basking shark and the megamouth shark). It feeds on macro-algae, plankton, krill, Christmas Island red crab larvae, and small nektonic life such as small squid or vertebrates. The many rows of teeth play no role in feeding; in fact, they are reduced in size in the whale shark. Instead, the shark sucks in a mouthful of water, closes its mouth and expels the water through its gills. During the slight delay between closing the mouth and opening the gill flaps, plankton is trapped against the dermal denticles which line its gill plates and pharynx. This fine sieve-like apparatus, which is a unique modification of the gill rakers, prevents the passage of anything but fluid out through the gills, trapping anything above 2 to 3 millimetres (0.079 to 0.12 in) in diameter. Material caught in the filter between the gill bars is swallowed. Whale sharks have been observed "coughing" and it is presumed that this is a method of clearing a build up of food particles in the gill rakers.

Behaviour toward divers

Despite its size, the whale shark does not pose significant danger to humans. Although massive, whale sharks are docile fish and sometimes allow swimmers to hitch a ride. Whale sharks are actually quite gentle and can play with divers. Divers and snorkelers can swim with this giant fish without risk, apart from unintentional blows from the shark’s large tail fin. In July 2011, several sources reported, with photos, an incident of a diver who, allegedly, was nearly sucked into the mouth of a whale shark (but escaped unharmed) off the coast of Isla Mujeres, Mexico.

The 10 Most Dangerous Animals in Australia

As fascinating as Australia might be, the Land Down Under is not without dangers, especially when it comes to the rich fauna. When choosing to travel to Australia, be sure to consider all the continent has in store, especially poisonous or lethal animals.

1. The Box Jellyfish
One of the most extremely lethal animals in the world, and implicitly Australian, often found on the continent. Found on the coast alongside the Great Barrier Reef, the box jellyfish possesses an extremely powerful venom. The stings are terribly painful and often fatal.
Be sure to include a bottle of vinegar in your first aid kit if you’ll be traveling in areas abound with these jellyfish. Vinegar applied for 30 seconds to the sting, then removing the tentacles with a towel, will reduce the damage. But you will need to seek medical attention as soon as possible.

2. The Taipan
The taipan is a large, fast and highly venomous snake often found throughout Australia. The taipan has the most toxic venom out of all the species worldwide, has a dark brown color and is often found in sugar fields where it hunts for rats. The snake is usually found in the far north of Australia, in Queensland, the Northern Territory and Western Australia, where the winter is mild. Taipan’s usually stay away from people but once cornered or threatened, they strike several times.

3. Saltwater Crocodile
The largest living member of the crocodilians and reptiles, the saltwater crocodile can grow up to 18 feet (5.45 meters) in length and is often found in Thailand, Vietnam and Northern Australia. They have been known to take on animals such an adult water buffalo and have often attacked people. It is usually well camouflaged both underwater or on dry land and strikes at an amazing speed. Its most powerful attack – the death roll – consists of grabbing its prey and rolling powerfully until it dies

4. Blue Ring Octopus
Another serious threat for those that wish to explore the waters of Australia is the blue-ringed octopus – one of the most toxic sea creatures in the world found off the coast of Australia, New Guinea, Indonesia, and the Philippines. Even though the octopus is only the size of a golf ball, there is no known antidote for its powerful venom. It causes motor paralysis, eventually leading to cardiac arrest. First aid treatment consists of pressure on the wound and mouth-to-mouth breathing that can last for several hours.

5. Stone Fish
Known as the most venomous fish in the world, the stone fish lives on the bottom of the reefs, camouflaged as a rock. It lives above the Tropic of Capricorn but can be found in the Queensland Great Barrier Reef as well. It’s venom comes from the dorsal area, that is lined with 13 spines, causing shock, paralysis and tissue death depending on the severity of the sting. First aid consists of immobilizing the venom by bandaging the affected area then applying a hot compress. The pain is said to be so excruciating that it lead to amputating the affected limb.

6. Red Back Spider
This species found all over the continent is Australia’s most famous deadly spider. The red striped spider has a neurotic venom that induces severe pain, however, deaths are rare. Thousands of people are bitten but only approximately 20% of the victims require treatment. Generally, the children and the elderly are the most exposed to the spider’s threat. This is one of the few spider species that displays sexual cannibalism while mating.

7. Brown Snake
There are several types of brown snakes but the Pseudonaja is the genus commonly found in Australia. Known as one of Australia’s most deadly creatures, the brown snake has a venom which quickly kills if it goes untreated. Even young snakes are capable of delivering a fatal bite to humans

8. Tiger Snake
The tiger snake is another of the many venomous snakes found Australia, particularly in the southern regions. The striped snakes are not generally aggressive and retreat whenever they have the chance. The tiger snake is known as one of the deadliest snakes in the world. Although anti-venom is readily available, mortality rates are around 45% if the bite is left untreated. In most states, the species is protected and any harming or injuring lead to a fine of up to $4,000.

9. Great White Shark
This exceptionally large shark known as the white death is known as world’s largest known predatory fish. They can be found in great numbers on the southern coasts of Australia and, even though they have often been depicted as fatal to humans, they do not target them as a prey. Many of the attacks we’re not fatal, the shark only performing test-biting, out of curiosity. Humans are not a good meal, considering the shark’s slow digestion compared to the human’s muscle to fat ratio.

10. Funnel web spider
The darkly colored spiders resembling tarantulas have fangs and chelicerae with ample venom glands, that can even penetrate fingernails or shoes. They can be found in the eastern coast of Australia, New South Wales, Victoria or Queensland. First aid consists of applying a bandage and wrapping the bitten limb. As with other spiders, the main treatment is the anti-venom.

source:http://blog.hotelclub.com/the-10-most-dangerous-animals-in-australia/