''Christinus marmoratus'', also known as marbled gecko or southern marbled gecko, is a species of

Gekkonidae Gekkonidae (the common geckos) is the largest family of geckos, containing over 950 described species in 64 genera. Members of the Gekkonidae comprise many of the most widespread gecko species, including house geckos ('' Hemidactylus''), tokay g ...

(gecko) native to southern mainland of Australia, from

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

. The species is well adapted to a variety of habitats, including city dwellings.''.

Taxonomy

The species was first formally described by

John Edward Gray John Edward Gray, FRS (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for ...

in 1845. The name he gave placed this group in the genus ''

Diplodactylus ''Diplodactylus'' is a genus of geckos of the family Diplodactylidae from Australia. They are sometimes called stone geckos or fat-tailed geckos. Member species are morphologically similar but genetically distinct. Species The following 27 specie ...

'' as ''Diplodactylus marmoratus''. Gray's description was based on four specimens that were preserved in spirits. They were collected on the Abrolhos Islands (off

), and were donated to the

British Museum The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It docum ...

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,

George Boulenger George Albert Boulenger (19 October 1858 – 23 November 1937) was a Belgian-British zoologist who described and gave scientific names to over 2,000 new animal species, chiefly fish, reptiles, and amphibians. Boulenger was also an active botani ...

placed ''D. marmoratus'' in the genus ''

Phyllodactylus ''Phyllodactylus'' is a genus of geckos distributed in South America and Central America, and as far north as the southern United States. They are commonly known as " leaf-toed geckos" in their native range, and otherwise as American leaf-toed ge ...

'' (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'' is a genus of Gekkonidae 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, marbling, are found in a variety of r ...

''. 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.

Description

Marbled Gecko (Christinus marmoratus) - head close up

Adults reach an average (snout-vent) length of 50mm, and weigh about 2.5g.Kearney M, Shine R, Comber S, Pearson D. 2001. Why do geckos group? An analysis of "social" aggregations in two species of Australian Lizards. Herpetologica 57:4, 411–422. ''C. marmoratus'' have fat reserves in their tails,Daniels CB. 1984. The importance of caudal lipid in the gecko Phyllodactylus marmoratus. Herpetologica 40:3, 337–344. which can be disconnected from their body (

autotomy Autotomy (from the Greek ''auto-'', "self-" and ''tome'', "severing", αὐτοτομία) or self-amputation, is the behaviour whereby an animal sheds or discards one or more of its own appendages, usually as a self-defense mechanism to elude ...

) 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 gecko. It occurs from northeastern

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

southwestern The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each sepa ...

Western Australia, as well as a number of islands off the coasts of

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

and Western Australia.King M, Rofe R. 1976. Karyotypic variation in the Australian Gekko Phyllodactylus marmoratus (Gray) (Gekkonidae: Reptilia). Chromosoma 54:75–87. They use a variety of habitats including open shrubland,

sclerophyll forest Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...

, riverine woodland and urban regions.Kearney M, Predavec M. 2000. Do nocturnal ectotherms thermoregulate? A study of the temperate gecko Christinus marmoratus. Ecology 81:11, 2984–2996.

Ecology and behaviour

''C. marmoratus'' is insectivorous and nocturnal. 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

eucalyptus ''Eucalyptus'' () is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Along with several other genera in the tribe Eucalypteae, including '' Corymbia'', they are commonly known as e ...

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 vigilanceStamps JA. 1988. Conspecific attraction and aggregation in territorial species. The American Naturalist 131:3, 329. 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 Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

by adjusting its posture, for instance, by raising or flattening the body to contact the rock substrate. They also seem to touch the rock with their snout before doing so, as if testing the temperature. ''C. marmoratus'' rarely vocalise; when they do, it is usually a squeaking call in response to attack.

References

*Edgar r. Waite F.L.S, C.M.Z.S, 1929 ''The Reptiles and Amphibians of South Australia'', Printed by Harbison Weir, Government Printer 31 January, p. 76, 7/- sixpence. {{DEFAULTSORT:Christinus marmoratus Reptiles of Western Australia Christinus Reptiles described in 1845 Taxa named by John Edward Gray Geckos of Australia