White's Tree Frog
Encyclopedia
The Australian Green Tree Frog, simply Green Tree Frog in Australia, White's Tree Frog, or Dumpy Tree Frog (Litoria caerulea) is a species
of tree frog
native to Australia
and New Guinea
, with introduced population
s in New Zealand
and the United States
. The species belongs to the genus
Litoria
. It is physiologically similar to some species of the genus, particularly the Magnificent Tree Frog
(Litoria splendida) and the Giant Tree Frog
(Litoria infrafrenata).
The Green Tree Frog is larger than most Australian frog
s, reaching 10 centimetres (4 inches) in length. The average lifespan of the frog in captivity, about sixteen years, is long in comparison with most frogs. Green Tree Frogs are docile and well suited to living near human dwellings. They are often found on windows or inside houses, eating insects drawn by the light. The Green Tree Frog screams when it's in danger to scare off its foe; and this particular frog squeaks when it is touched.
Due to its physical and behavioural traits, the Green Tree Frog has become one of the most recognisable frogs in its region, and is a popular exotic pet
throughout the world. The skin secretions of the frog have antibacterial
and antiviral
properties that may prove useful in pharmaceutical
preparations.
genus with dozens of frog species endemic to Australasia
. The common name of the species, "White's Tree Frog", is in honour of John White
's first description in 1790. The Green Tree Frog was the first Australian frog scientifically classified; the specimen found its way into the collection of Sir Joseph Banks, but was destroyed with the German bombing of the Hunterian Museum at the Royal College of Surgeons in London in World War II.
The species was originally called the "blue frog" (Rana caerulea) despite its green colour. The original specimens White sent to England
were damaged by the preservative and appeared blue. The colour of the frog is caused by blue and green pigment
s covered in a yellow layer; the preservative destroyed the yellow layer and left the frog with a blue appearance. The specific epithet, caerulea, which is Latin for blue, has remained. The frog is also known more simply as the "Green Tree Frog." However, that name is often given to the most common large green tree frog in a region, for example, the American green tree frog
(Hyla cinerea).
es, typical of the Litoria genus. The fingers are about one-third webbed, and the toes nearly three-quarters webbed. The tympanum (a skin membrane similar to an eardrum
) is visible.
The Green Tree Frog appears similar to the Magnificent Tree Frog (Litoria splendida), which inhabits only north-western Australia and can be distinguished by the presence of large parotoid
s and rostral glands on the head. The Giant Tree Frog (Litoria infrafrenata) is also sometimes confused with the Green Tree Frog. The main difference is a distinct white stripe along the edge of the lower jaw of the Giant Tree Frog, which is not present in the Green Tree Frog.
The tadpole's appearance changes throughout its development. The length of the species' tadpoles ranges from 8.1 millimeters (once hatched) to 44 millimetres. They are initially mottled with brown, which increases in pigmentation (to green or brown) during development. The underside begins dark and then lightens, eventually to white in adults. The eggs are brown, in a clear jelly and are 1.1–1.4 millimetres in diameter.
Although frogs have lungs, they absorb oxygen through their skin, and for this to occur efficiently, the skin must be moist. A disadvantage of moist skin is that pathogen
s can thrive on it, increasing the chance of infection. To counteract this, frogs secrete peptide
s that destroy these pathogens. The skin secretion
from the Green Tree Frog contains caerins, a group of peptides with antibacterial and antiviral properties. It also contains caerulins, which have the same physiological effects as CCK-8
, a digestive hormone and hunger suppressant. Several peptides from the skin secretions of the Green Tree Frog have been found to destroy HIV
without harming healthy T-cells.
The Green Tree Frog is native to northern and eastern regions of Australia and to southern New Guinea. Distribution is limited mostly to areas with a warm, wet tropic
al climate. In New Guinea, the Green Tree Frog is restricted to the drier, southern region. Its range spans from Irian Jaya to Port Moresby
, and is most abundant on Daru Island
. There have been isolated records in northern New Guinea, however this is thought to have been through introduction by humans. The International Conservation Union (IUCN) suggests "scattered locations" in both New Guinea and Indonesia
.
The species has been introduced to both the United States and New Zealand. In the United States, it is restricted to two regions within Florida
, where it was possibly introduced through the pet trade. Only small populations have been found in Florida, and it is unknown whether they have caused any ecological
damage as an invasive species
. In New Zealand, a population was once present; however, there have been no sightings since the 1950s.
Green Tree Frogs are very docile. They are nocturnal and come out in early evenings to call (in spring and summer) and hunt for food. During the day they find cool, dark, and moist areas to sleep such as tree holes or rock crevices. In the winter, Green Tree Frogs do not call and are not usually seen.
Depending on their location, Green Tree Frogs occupy various habitats. Typically, they are found in the canopy of trees near a still-water source. However, they can survive in swamps (among the reed
s) or in grasslands in cooler climates. Green Tree Frogs are well known for inhabiting water sources inside houses, such as sinks or toilets. They can also be found on windows eating insects. They will occupy tanks (cistern
s), downpipes (downspouts), and gutters, as these have a high humidity and are usually cooler than the external environment. The frogs are drawn to downpipes and tanks during mating season, as the fixtures amplify their call.
The species' call is a low, slow Brawk-Brawk-Brawk, repeated many times. For most of the year, they call from high positions, such as trees and gutters. During mating season the frogs descend, although remaining slightly elevated, and call close to still-water sources, whether temporary or permanent. Like many frogs, Green Tree Frogs call not only to attract a mate. They have been observed calling to advertise their location outside the mating season, usually after rain, for reasons that are uncertain to researchers. They will emit a stress call whenever they are in danger, such as when predators are close or when a person steps on a log in which a frog resides.
The species' diet consists mainly of insect
s and spider
s, but can include smaller frogs and even small mammal
s. Frog teeth are not suited to cutting up prey, so the prey must fit inside the mouth of the frog. Many frogs propel their sticky tongues at prey. The prey sticks, and is consumed. A Green Tree Frog will use this technique for smaller prey; however for larger prey, it pounces, then forces the prey into its mouth with its hands.
The frog has a few native predators, among them snake
s and a few species of lizard
s and bird
s. Since the European settlement of Australia, non-native predators have been introduced, primarily dogs and cats. The species has an average life expectancy in captivity of sixteen years, but some have been known to live for over twenty years, which is long for a frog. The average life expectancy in the wild is lower than in captivity, due to predation.
owners. It is also one of the easier frogs to care for: their diet is broad and they have a strong resistance to disease. One problem commonly associated with keeping this species as a pet is overfeeding; Green Tree Frogs tend to become obese if overfed. In the wild, exertion of energy is required for a frog to capture its prey. However, in captivity they are usually given live feed in a confined space. This lessens the activity needed for feeding, resulting in weight gain. An overweight member of the species will deposit fat layers over the top of the head and body, giving it "dumpy" appearance. Thus the name, "Dumpy Tree Frog."
—under the federal Environment Protection and Biodiversity Conservation Act 1999. The IUCN lists it as a "least concern
" species, given its broad range and population, balanced habitats, and because it is likely not declining fast enough for more threatened status.
Some of the Green Tree Frog's natural habitat has been destroyed. Also, some of the frogs have been found to be infected with chytrid fungus (causing chytridiomycosis
). These two factors associated with other frogs' declines in Australia threaten to reduce the population of the Green Tree Frog. However, because of the long life expectancy of this species, any effects of a reduced reproduction rate will take longer to spot than they would in a species with a shorter life expectancy.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of tree frog
Tree frog
Hylidae is a wide-ranging family of frogs commonly referred to as "tree frogs and their allies". However, the hylids include a diversity of frog species, many of which do not live in trees, but are terrestrial or semi-aquatic.-Characteristics:...
native to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
, with introduced population
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
s in New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. The species belongs to the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Litoria
Litoria
Litoria is a genus of Hylidae tree frogs native to Australia, the Bismarck Archipelago, the Solomon Islands, New Guinea, the Lesser Sunda Islands, the Moluccan Islands, and Timor. They are sometimes collectively referred to as Australasian treefrogs...
. It is physiologically similar to some species of the genus, particularly the Magnificent Tree Frog
Magnificent Tree Frog
The Magnificent Tree Frog or Splendid Tree Frog is a tree frog species that was first described in 1977. It has a limited range, only occurring on the north-western coast of Australia in the Northern Territory and Western Australia...
(Litoria splendida) and the Giant Tree Frog
Giant Tree Frog
The White-lipped Tree Frog , also known as the Giant Tree Frog, is the world's largest tree frog. This species is native to the rainforests of Northern Queensland, New Guinea, the Bismarck Islands and the Admiralty Islands....
(Litoria infrafrenata).
The Green Tree Frog is larger than most Australian frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s, reaching 10 centimetres (4 inches) in length. The average lifespan of the frog in captivity, about sixteen years, is long in comparison with most frogs. Green Tree Frogs are docile and well suited to living near human dwellings. They are often found on windows or inside houses, eating insects drawn by the light. The Green Tree Frog screams when it's in danger to scare off its foe; and this particular frog squeaks when it is touched.
Due to its physical and behavioural traits, the Green Tree Frog has become one of the most recognisable frogs in its region, and is a popular exotic pet
Exotic pet
An exotic pet is a rare or unusual animal pet, or an animal kept as a pet which is not commonly thought of as a pet.The definition is an evolving one; some rodents, reptiles, and amphibians have become firmly enough established in the world of animal fancy to no longer be considered exotic...
throughout the world. The skin secretions of the frog have antibacterial
Antiseptic
Antiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction...
and antiviral
Antiviral drug
Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics for bacteria, specific antivirals are used for specific viruses...
properties that may prove useful in pharmaceutical
Pharmacology
Pharmacology is the branch of medicine and biology concerned with the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function...
preparations.
Taxonomy
The Green Tree Frog shares the LitoriaLitoria
Litoria is a genus of Hylidae tree frogs native to Australia, the Bismarck Archipelago, the Solomon Islands, New Guinea, the Lesser Sunda Islands, the Moluccan Islands, and Timor. They are sometimes collectively referred to as Australasian treefrogs...
genus with dozens of frog species endemic to Australasia
Australasia
Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...
. The common name of the species, "White's Tree Frog", is in honour of John White
John White (surgeon)
John White was an English surgeon and botanical collector.White was born in Sussex and entered the Royal Navy on 26 June 1778 as third surgeon's mate. He was promoted surgeon in 1780, and was the principal surgeon during the voyage of the First Fleet to Australia...
's first description in 1790. The Green Tree Frog was the first Australian frog scientifically classified; the specimen found its way into the collection of Sir Joseph Banks, but was destroyed with the German bombing of the Hunterian Museum at the Royal College of Surgeons in London in World War II.
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
were damaged by the preservative and appeared blue. The colour of the frog is caused by blue and green pigment
Pigment
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...
s covered in a yellow layer; the preservative destroyed the yellow layer and left the frog with a blue appearance. The specific epithet, caerulea, which is Latin for blue, has remained. The frog is also known more simply as the "Green Tree Frog." However, that name is often given to the most common large green tree frog in a region, for example, the American green tree frog
American green tree frog
The American green tree frog is a common species of New World tree frog belonging to the genus Hyla. It is a common backyard species that is popular as a pet, and is the state amphibian of Georgia and Louisiana.-Description:...
(Hyla cinerea).
Description
The Green Tree Frog can grow up to 10 centimetres (4 inches) in length. Its color depends on the temperature and colour of the environment, ranging from brown to green; the ventral surface is white. The frog occasionally has small, white, irregularly shaped spots on its back, up to five millimetres in diameter, which increase in number with age. The frog has large discs at the end of its toes, of about five millimetres in diameter at maturity. These help the frogs grip while climbing and allow them to climb vertically on glass. The eyes are golden and have horizontal irisIris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
es, typical of the Litoria genus. The fingers are about one-third webbed, and the toes nearly three-quarters webbed. The tympanum (a skin membrane similar to an eardrum
Eardrum
The eardrum, or tympanic membrane, is a thin membrane that separates the external ear from the middle ear in humans and other tetrapods. Its function is to transmit sound from the air to the ossicles inside the middle ear. The malleus bone bridges the gap between the eardrum and the other ossicles...
) is visible.
The Green Tree Frog appears similar to the Magnificent Tree Frog (Litoria splendida), which inhabits only north-western Australia and can be distinguished by the presence of large parotoid
Parotoid gland
The parotoid gland is an external skin gland on the back, neck, and shoulder of toads and some frogs and salamanders. It secretes a milky alkaloid substance to deter predators...
s and rostral glands on the head. The Giant Tree Frog (Litoria infrafrenata) is also sometimes confused with the Green Tree Frog. The main difference is a distinct white stripe along the edge of the lower jaw of the Giant Tree Frog, which is not present in the Green Tree Frog.
Although frogs have lungs, they absorb oxygen through their skin, and for this to occur efficiently, the skin must be moist. A disadvantage of moist skin is that pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s can thrive on it, increasing the chance of infection. To counteract this, frogs secrete peptide
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
s that destroy these pathogens. The skin secretion
Secretion
Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland. In contrast to excretion, the substance may have a certain function, rather than being a waste product...
from the Green Tree Frog contains caerins, a group of peptides with antibacterial and antiviral properties. It also contains caerulins, which have the same physiological effects as CCK-8
Cholecystokinin
Cholecystokinin is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein...
, a digestive hormone and hunger suppressant. Several peptides from the skin secretions of the Green Tree Frog have been found to destroy HIV
HIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
without harming healthy T-cells.
Distribution
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
al climate. In New Guinea, the Green Tree Frog is restricted to the drier, southern region. Its range spans from Irian Jaya to Port Moresby
Port Moresby
Port Moresby , or Pot Mosbi in Tok Pisin, is the capital and largest city of Papua New Guinea . It is located on the shores of the Gulf of Papua, on the southeastern coast of the island of New Guinea, which made it a prime objective for conquest by the Imperial Japanese forces during 1942–43...
, and is most abundant on Daru Island
Daru Island
Daru Island is an island in the Western Province of Papua New Guinea, the town on the island goes by the same name and is the capital of the Province, housing the vast majority of its population of 20,524 . It is elliptical in shape, with dimensions of 5.0 by 3.7 km², 14.7 km² in area,...
. There have been isolated records in northern New Guinea, however this is thought to have been through introduction by humans. The International Conservation Union (IUCN) suggests "scattered locations" in both New Guinea and Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
.
The species has been introduced to both the United States and New Zealand. In the United States, it is restricted to two regions within Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
, where it was possibly introduced through the pet trade. Only small populations have been found in Florida, and it is unknown whether they have caused any ecological
Ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
damage as an invasive species
Invasive species
"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
. In New Zealand, a population was once present; however, there have been no sightings since the 1950s.
Ecology, behaviour and life history
Depending on their location, Green Tree Frogs occupy various habitats. Typically, they are found in the canopy of trees near a still-water source. However, they can survive in swamps (among the reed
Phragmites
Phragmites, the Common reed, is a large perennial grass found in wetlands throughout temperate and tropical regions of the world. Phragmites australis is sometimes regarded as the sole species of the genus Phragmites, though some botanists divide Phragmites australis into three or four species...
s) or in grasslands in cooler climates. Green Tree Frogs are well known for inhabiting water sources inside houses, such as sinks or toilets. They can also be found on windows eating insects. They will occupy tanks (cistern
Cistern
A cistern is a waterproof receptacle for holding liquids, usually water. Cisterns are often built to catch and store rainwater. Cisterns are distinguished from wells by their waterproof linings...
s), downpipes (downspouts), and gutters, as these have a high humidity and are usually cooler than the external environment. The frogs are drawn to downpipes and tanks during mating season, as the fixtures amplify their call.
The species' call is a low, slow Brawk-Brawk-Brawk, repeated many times. For most of the year, they call from high positions, such as trees and gutters. During mating season the frogs descend, although remaining slightly elevated, and call close to still-water sources, whether temporary or permanent. Like many frogs, Green Tree Frogs call not only to attract a mate. They have been observed calling to advertise their location outside the mating season, usually after rain, for reasons that are uncertain to researchers. They will emit a stress call whenever they are in danger, such as when predators are close or when a person steps on a log in which a frog resides.
The species' diet consists mainly of insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s, but can include smaller frogs and even small mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s. Frog teeth are not suited to cutting up prey, so the prey must fit inside the mouth of the frog. Many frogs propel their sticky tongues at prey. The prey sticks, and is consumed. A Green Tree Frog will use this technique for smaller prey; however for larger prey, it pounces, then forces the prey into its mouth with its hands.
The frog has a few native predators, among them snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
s and a few species of lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s and bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s. Since the European settlement of Australia, non-native predators have been introduced, primarily dogs and cats. The species has an average life expectancy in captivity of sixteen years, but some have been known to live for over twenty years, which is long for a frog. The average life expectancy in the wild is lower than in captivity, due to predation.
As a pet
The Green Tree Frog is one of the most popular pet frogs throughout the world. Its docile nature, often cartoon-like appearance, and long life expectancy make it an attractive choice for exotic-petExotic pet
An exotic pet is a rare or unusual animal pet, or an animal kept as a pet which is not commonly thought of as a pet.The definition is an evolving one; some rodents, reptiles, and amphibians have become firmly enough established in the world of animal fancy to no longer be considered exotic...
owners. It is also one of the easier frogs to care for: their diet is broad and they have a strong resistance to disease. One problem commonly associated with keeping this species as a pet is overfeeding; Green Tree Frogs tend to become obese if overfed. In the wild, exertion of energy is required for a frog to capture its prey. However, in captivity they are usually given live feed in a confined space. This lessens the activity needed for feeding, resulting in weight gain. An overweight member of the species will deposit fat layers over the top of the head and body, giving it "dumpy" appearance. Thus the name, "Dumpy Tree Frog."
Conservation
Australian law gives protected status to the Green Tree Frog—along with all Australian faunaFauna of Australia
The fauna of Australia consists of a huge variety of animals; some 83% of mammals, 89% of reptiles, 90% of fish and insects and 93% of amphibians that inhabit the continent are endemic to Australia...
—under the federal Environment Protection and Biodiversity Conservation Act 1999. The IUCN lists it as a "least concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
" species, given its broad range and population, balanced habitats, and because it is likely not declining fast enough for more threatened status.
Some of the Green Tree Frog's natural habitat has been destroyed. Also, some of the frogs have been found to be infected with chytrid fungus (causing chytridiomycosis
Chytridiomycosis
Chytridiomycosis is an infectious disease of amphibians, caused by the chytrid Batrachochytrium dendrobatidis, a non-hyphal zoosporic fungus. Chytridiomycosis has been linked to dramatic population declines or even extinctions of amphibian species in western North America, Central America, South...
). These two factors associated with other frogs' declines in Australia threaten to reduce the population of the Green Tree Frog. However, because of the long life expectancy of this species, any effects of a reduced reproduction rate will take longer to spot than they would in a species with a shorter life expectancy.