''Diplodactylus tessellatus'', commonly known as the tessellated gecko, is a small terrestrial lizard found distributed in inland New South Wales, Queensland, Northern Territory, South Australia and the north western corner of Victoria. The tessellated gecko is one of 26 species in the genus '' Diplodactylus'' all of which are confined to continental Australia. A small gecko varying in colour from grey to rich reddish-brown with a highly variable dorsal pattern.

Taxonomy & Phylogeny

The tessellated gecko was first described by a German-born British zoologist,

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish ( Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of Octobe ...

, and herpetologist Albert Gunther in 1875. ''Diplodactylus tessellates'' is a species of

gecko Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from . Geckos ar ...

s of the genus '' Diplodactylus'' within the family Diplodactylidae. Australian diplodactyline geckos are the only extant squamate group thought to have been in Australia before its separation from other east Gondwanan landmasses. D. tessellatus is thought to have speciated from '' Diplodactylus vittatus'' between 12 and 20 million years ago during the Miocene Epoch of the

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

period. A sister taxon relationship between ''D. galeatus'' and ''D. tessellatus'' is supported.

Description

Morphology

With an average adult length of 9 cm in length, the tessellated gecko has a moderate body a short fleshy tail with enlarged conical scales in rings. Their body colours are varied from pale greys to rich reds with a highly variable pattern. Along the mid- dorsal region of the body and tail there is often irregular serious of pale yellow or blackish spots that are often in pairs. Pre-anal pores are absent with 4–13 post-anal tubercles. A trait common in other species of the genus '' Diplodactylus'' is the possession of slightly depressed, narrow long digits. Near the hind limb, males have a unique paracloacal spur positioned near the top of the hemipenal bulge. Hatchlings are often brighter and around 25–30% the average adult size.

Population & Ecology

In Kinchega National Park from 1985 to 1987 the life history and population ecology of the tessellated gecko was studied by Klaus Henle. The studies produced data showing there were short peaks of high mortality in spring or summer and low mortalities for the rest of the year, especially in winter when they are restricted or inactive. Dispersal ranges for individuals are from 50 to 100 meters from their birth site. They are most active from the spring months of September through to the end of May before hibernating during winter.

Habitat and distribution

A terrestrial gecko that is widely distributed throughout the drier reaching interiors of New South Wales, Queensland, Northern Territory, South Australia and Victoria. During the day it may be found resting in habitats such as ground cracks, abandoned spider holes, crevices, under debris or fallen timber which all provide a camouflage from predation. Emerges at night to feed on insects. Can be quiet abundant in the right conditions such as black soiled flood plains of larger inland rivers.

Diet

Being an arthropod food generalist, the main diet consists of species of the

Orthoptera Orthoptera () is an order of insects that comprises the grasshoppers, locusts, and crickets, including closely related insects, such as the bush crickets or katydids and wētā. The order is subdivided into two suborders: Caelifera – grassho ...

order (crickets and grass hoppers), spiders and

Diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced ...

species, with a favourite delicacy of termites. While widely foraging, ''D. tessellatus'' is a sit-and-wait predator often sitting at the same spot for hours. Before breeding and hibernation in winter, food intake will increase to help produce fat storage.

Breeding

The tessellated gecko will on average produce clutches of 2 eggs with an incubation period of around 50–60 days if under the right temperature conditions of around 28 degrees. The eggs average size is 13.5 mm long and 6.5 mm wide. The hatchlings average size is around 24 mm in total length and reach sexual maturity at one year old. Under favourable phenological conditions such as abundant food availability and stable climate, a healthy female can produce up to two clutches without any detrimental harm to her own fitness. In natural conditions the first clutch will be laid in November and the second in January with an observed egg mortality rate of 56%. Oviductal eggs can be detected by using the palpation method.

Threats

Introduced species

In Australia introduced species have caused the greatest number of extinctions. Exotic feral animals such as cats can have a negative effect on terrestrial geckos with mortality rates often correlating with predation at night. Ground foraging species such as ''D. tessellatus'' can often fall prey to an unsuspecting cat that has adapted to its environment.

References

{{Taxonbar, from=Q3028969 Diplodactylus Endemic fauna of Australia Geckos of Australia Reptiles described in 1875 Taxa named by Albert Günther