Marbled gecko
Encyclopedia
Christinus marmoratus (synonym: Phyllodactylus marmoratus) is a species of Gekkonidae (gecko) native to southern mainland of Australia
, from Victoria
to Western Australia
. The species is well adapted to a variety of habitats, including city dwellings.
This group, along with other related taxa, are also known as Marbled Gecko.
in 1845. The name he gave placed this group in the genus Diplodactylus
as Diplodactylus marmoratus. Gray's description was based on four specimens that were preserved in spirits. They were collected on the Abrolhos islands (off Western Australia
), and were donated to the British museum from the collection of a “Mr. Gilbert.” Gray examined another preserved specimen of D. marmoratus (from a different donor) which was discoloured, leading him to mistakenly describe it as a separate species (Goniodactylus australis) in the same publication. In 1885 Boulenger placed D. marmoratus in the genus Phyllodactylus
(the leaf-toed geckos). It remained in that genus until 1984, when a revision by Wells and Wellington placed it in the genus Christinus
.
A study conducted by King in 1977 showed that C. marmoratus exhibits considerable geographic variation in karyotype
across its range. Further investigation by Donnellan et al. (2000) led to the species being recognized as a composite of two subspecies; C. marmoratus marmoratus and C. marmoratus dactylus. The two subspecies are commonly referred to as the Western Marbled Gecko and the Southern Marbled Gecko.
Their placement within the genus may be summarised as follows:
when threatened to aid in escape. Tails take about eight months to regenerate. Fully regenerated tails are characterized by an abrupt change in dorsal skin colouring and pattern at the level of the original fracture plane. Original tails also have much more developed muscular bands. C. marmoratus hatchlings do not have any fat in the tail, and they drop it more readily than adults do.
. It occurs from northeastern New South Wales
to southwestern Western Australia, as well as a number of islands off the coasts of South Australia
and Western Australia. They use a variety of habitats including open shrubland, sclerophyll forest, riverine woodland and urban regions.
trees during the daytime. C. marmoratus are commonly found in aggregations of up to 10 individuals, and most aggregations contain one male. Given that many geckos have been reported to engage in territorial behaviour, it is surprising that C. marmoratus aggregate so commonly (Kearney et al. reported that one quarter of individuals they found were in aggregations). It has been suggested that this activity may be related to mating success, increased vigilance or simply attraction to high-quality habitat. Angiletta and Werner (1998) found that the preferred body temperature of C. marmoratus was 27.7°C., which is much higher than their average body temperatures during the day or night. Subsequent investigation by Kearney and Predavec (2000) revealed that C. marmoratus may thermoregulate by adjusting it’s posture, such as raising or flattening the body to contact the rock substrate. Interestingly, they seem to touch the rock with their snout before doing so, as if testing the temperature.
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...
, from Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
to Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. The species is well adapted to a variety of habitats, including city dwellings.
This group, along with other related taxa, are also known as Marbled Gecko.
Taxonomy
The species was first formally described by John Edward GrayJohn Edward Gray
John Edward Gray, FRS was a British zoologist. He was the elder brother of George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray ....
in 1845. The name he gave placed this group in the genus Diplodactylus
Diplodactylus
Diplodactylid Geckos are the largest genus of the Diplodactylinae, containing 40 or so species. Most are small, between 3" and 4", with the larger ones reaching no more than 6"....
as Diplodactylus marmoratus. Gray's description was based on four specimens that were preserved in spirits. They were collected on the Abrolhos islands (off Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
), and were donated to the British museum from the collection of a “Mr. Gilbert.” Gray examined another preserved specimen of D. marmoratus (from a different donor) which was discoloured, leading him to mistakenly describe it as a separate species (Goniodactylus australis) in the same publication. In 1885 Boulenger placed D. marmoratus in the genus Phyllodactylus
Phyllodactylus
Phyllodactylus is a genus of geckos distributed in South America and Central America, and as far north as southern United States. They are commonly known as "Leaf-toed geckos" in their native range, and otherwise as American leaf-toed geckos to distinguish them from unrelated genera with similar...
(the leaf-toed geckos). It remained in that genus until 1984, when a revision by Wells and Wellington placed it in the genus Christinus
Christinus
Christinus, a genus of Gekkonidae, are geckos found in southern regions of Australia. It contains species and subspecies that are regionally termed as Marbled Geckos. The contrasted patterns of these geckos, its marbling, are found in a variety of reddish brown, grey, silver, white, black and...
.
A study conducted by King in 1977 showed that C. marmoratus exhibits considerable geographic variation in karyotype
Karyotype
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...
across its range. Further investigation by Donnellan et al. (2000) led to the species being recognized as a composite of two subspecies; C. marmoratus marmoratus and C. marmoratus dactylus. The two subspecies are commonly referred to as the Western Marbled Gecko and the Southern Marbled Gecko.
Their placement within the genus may be summarised as follows:
- ChristinusChristinusChristinus, a genus of Gekkonidae, are geckos found in southern regions of Australia. It contains species and subspecies that are regionally termed as Marbled Geckos. The contrasted patterns of these geckos, its marbling, are found in a variety of reddish brown, grey, silver, white, black and...
- Christinus alexanderiChristinus alexanderiChristinus alexanderi, a species of Gekkonidae, are geckos found in the Nullarbor Plain of Australia. It is one of the many species and subspecies that are regionally termed as Marbled Geckos.-Description:...
(endemic to Nullarbor PlainNullarbor PlainThe Nullarbor Plain is part of the area of flat, almost treeless, arid or semi-arid country of southern Australia, located on the Great Australian Bight coast with the Great Victoria Desert to its north. It is the world's largest single piece of limestone, and occupies an area of about...
) - Christinus guentheriChristinus guentheriChristinus guentheri is a species of lizard in the Gekkonidae family.It is found at Australia islands, at the Norfolk and Lord Howe Island, and has a common name Lord Howe Island Southern Gecko....
, (Lord HoweLord Howe IslandLord Howe Island is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, directly east of mainland Port Macquarie, and about from Norfolk Island. The island is about 11 km long and between 2.8 km and 0.6 km wide with an area of...
and Norfolk IslandNorfolk IslandNorfolk Island is a small island in the Pacific Ocean located between Australia, New Zealand and New Caledonia. The island is part of the Commonwealth of Australia, but it enjoys a large degree of self-governance...
) - Christinus marmoratus, (widespread: southern mainland, northwest interior)
- Christinus marmoratus macrodactylus
- Christinus marmoratus marmoratus
- Christinus alexanderi
Description
Adults reach an average (snout-vent) length of 50mm, and weigh about 2.5g. C. marmoratus have fat reserves in their tails, which can be disconnected from their body autotomyAutotomy
Autotomy or self amputation is the act whereby an animal severs one or more of its own appendages, usually as a self-defense mechanism designed to elude a predator's grasp...
when threatened to aid in escape. Tails take about eight months to regenerate. Fully regenerated tails are characterized by an abrupt change in dorsal skin colouring and pattern at the level of the original fracture plane. Original tails also have much more developed muscular bands. C. marmoratus hatchlings do not have any fat in the tail, and they drop it more readily than adults do.
Distribution and habitat
C. marmoratus is Australia’s most southerly geckoGecko
Geckos are lizards belonging to the infraorder Gekkota, found in warm climates throughout the world. They range from 1.6 cm to 60 cm....
. It occurs from northeastern New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
to southwestern Western Australia, as well as a number of islands off the coasts of South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...
and Western Australia. They use a variety of habitats including open shrubland, sclerophyll forest, riverine woodland and urban regions.
Ecology and behaviour
C. marmoratus is insectivorous and diurnal. During the hot summer months they generally use deep crevices and burrows as their daytime retreat sites, and in cooler weather they aggregate under rocks. Riverine populations generally rest under the thick exfoliating bark of large eucalyptusEucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
trees during the daytime. C. marmoratus are commonly found in aggregations of up to 10 individuals, and most aggregations contain one male. Given that many geckos have been reported to engage in territorial behaviour, it is surprising that C. marmoratus aggregate so commonly (Kearney et al. reported that one quarter of individuals they found were in aggregations). It has been suggested that this activity may be related to mating success, increased vigilance or simply attraction to high-quality habitat. Angiletta and Werner (1998) found that the preferred body temperature of C. marmoratus was 27.7°C., which is much higher than their average body temperatures during the day or night. Subsequent investigation by Kearney and Predavec (2000) revealed that C. marmoratus may thermoregulate by adjusting it’s posture, such as raising or flattening the body to contact the rock substrate. Interestingly, they seem to touch the rock with their snout before doing so, as if testing the temperature.