Hemisphaeriodon

The pink-tongued skink (''Cyclodomorphus gerrardii'') is a species of lizard in the family Scincidae. ''C. gerrardii'' is endemic to Australia, where it is also called commonly the pink-tongued lizard. As suggested by these common names, its distinguishing characteristic is a pink tongue as opposed to the blue tongue of lizards of the closely related genus '' Tiliqua''.

Etymology

The specific name, ''gerrardii'', is in honor of British herpetologist Edward Gerrard (1810-1910), who was Gray's "right-hand man" at the British Museum.

Geographic range

''C. gerrardii'' is endemic to Australia. It can be found from Springwood, New South Wales, along the eastern coastal country and eastern ranges to the Cairns Region, Queensland.

Description

''C. gerrardii'' is a relatively large lizard of up to total length (including tail). It has a slender body with a long, slender and slightly prehensile tail about the same length as the body. The limbs are well developed with long digits and sharp claws. The neck is well pronounced, and the head is relatively large, wider in males than in females. In adults the tongue is pink. ''C. gerrardii'' has a slate-grey to fawn dorsal ground colour with dark grey to brown or black cross bands. These bands are more pronounced in males and less so in females. There are about 20 cross bands from the neck to the tip of the tail, which run slightly backwards laterally. The ventral surfaces of ''C. gerrardii'' are white to pinkish or creamy brown and may be marbled on the cross bands. The scales are smooth and, on the head, edged with a darker colour. The tip of the snout is dark in adults with some darker spots on the head. The limbs are spotted or streaked darkly. All juveniles are marked with pronounced black cross bands on a very light grey ground colour. There are several dark spots on the head, especially under the eyes. The tip of the snout is light in colour and the tongue and mouth are blue. Similar species (Cogger 2000): ''C. gerrardii'' has been associated with the genus '' Tiliqua'' as well as the genus ''Cyclodomorphus'' due to their close relation (previous names: ''Cyclodomorphus gerrardii'' and ''Tiliqua gerrardii''). ''C. gerrardii'' is very similar in appearance to the eastern blue-tongue, ''Tiliqua scincoides''; however, ''C. gerrardii'' has, true to its common name, a pink tongue as an adult. It is also much more slender than ''T. scincoides'', having a more slender body, a much longer and narrower tail as well as a smaller head. In addition, the limbs are more developed and longer than those of the blue-tongues.

Ecology and behaviour

''C. gerrardii'' inhabits wet sclerophyll forests and rainforests as well as moist areas in woodlands. It shelters beneath leaf litter, in hollow logs, and in crevices of rocks and trees. Its slender body and limbs are an adaptation for moving in thick undergrowth. ''C. gerrardii'' moves with lateral undulations on smooth surfaces, but holds its hind limbs close to the body and moves its tail in a side-winding motion when moving through grass and when climbing on branches, using only the forelimbs. Its main diet consists of snails and slugs, for which it forages during twilight hours and at night in summer, and also during the day in cooler months. To crush the shells of snails, ''C. gerrardii'' uses its large and flattened teeth in the back of the upper and lower jaw. ''C. gerrardii'' is a good climber, using its semi-prehensile tail as a supporting aid and, although only partially arboreal, climbing trees to feed when necessary. The juveniles seem to climb vegetation more frequently to avoid predation. When threatened, ''C. gerrardii'' raises its body off the ground to appear larger, and flickers or vibrates its tongue rapidly similar to snakes.

Breeding biology

In ''C. gerrardii'' courtship occurs in early spring for a period of six weeks, during which time males have been observed to fight. In mating, the male grasps the female's head with his jaws and mounts her. After an estimated gestation period of 101 to 110 days, females produce large litters of 20 to 30 (largest recorded: 67) live-young in early summer.Wilson SK, Knowles DG (1988). ''Australian Reptiles: A Photographic Reference of Australia''. Sydney: Collins Australia. During birth, the female holds her hind legs close to her body, as when moving through grass, giving single births about every 30 minutes during which she moves around. The young are born curled up in a foetal membrane, which they eat after breaking free. Immediately after birth, the young start flickering their tongues. The tongue and mouth are dark blue and the ventral surface is black in juveniles, changing to pink and mauve respectively after about three months. The young are independent from straight after birth without any parental care and start feeding on slugs and snails. Age at sexual maturity is about 22 months.

References

Further reading

* Boulenger GA (1887). ''Catalogue of the Lizards in the British Museum (Natural History). Second Edition. Volume III. ... Scincidæ ...'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xii + 575 pp. + Plates I-XL. (''Hemisphæriodon gerrardii'', pp. 148–149).
* Cogger HG (2014). ''Reptiles and Amphibians of Australia, Seventh Edition''. Clayton, Victoria, Australia: CSIRO Publishing. xxx + 1,033 pp. .
* Gray JE (1845). ''Catalogue of the Specimens of Lizards in the Collection of the British Museum.'' London: Trustees of the British Museum. (Edward Newman, printer). xxviii + 289 pp. (''Hinulia gerrardii'', new species, p. 75).
* Greer AE (1989). ''The Biology and Evolution of Australian Lizards''. Chipping Norton, New South Wales: Surrey Beatty & Sons. 264 pp. .
*Healey J (1997). ''The Reader’s Digest Encyclopaedia of Australian Wildlife''. Australia: Reader's Digest.
*Hitz, Robert; Shea, Glenn; Hauschild, Andree; Henle, Klaus; Werning, Heiko (2004). ''Blue-tongued Skinks: Contributions to the knowledge of'' Tiliqua ''and'' Cyclodomorphus. Münster: Schmidt. .
*Longley G (1938). "Notes on a pink-tongued skink (''Haemisphaeriodon gerrardii'' )". ''Proc. Royal Zool. Soc. New South Wales'' 1937-1938: 19-21.
* Macleay W (1885). "On some reptilia lately received from the Herbert River District, Queensland". ''Proc. Linnean Soc. New South Wales'' 10: 64-68.
*Mitchell FJ (1951). "The scincid genera ''Egernia'' and ''Tiliqua'' (Lacertilia)". ''Records of the South Australian Museum'' 9: 275-308.
* Peters W (1867). "''Herpetologische Notizen'' ". ''Monatsberichte der Königlich-Preussischen Akademie der Wissenschaften zur Berlin'' 1867: 13-37. (''Hemisphaeriodon'', new genus, and ''Hemisphaeriodon gerrardii'', new combination, p. 24). (in German).
*Shea G (1982). "Observations on some members of the genus ''Tiliqua'' ". ''Herpetofauna'' 13 (2): 18-20.
*Wilhoft CW (1960). "Observations on adults and juveniles of ''Hemisphaeriodon gerrardii'' in captivity". ''North Queensland Naturalist'' 28: 3-4.
*Wilson, Steve; Swan, Gerry (2003). ''Reptiles of Australia''. Princeton Field Guides. Princeton, New Jersey: Princeton University Press.
*Wilson, Steve; Swan, Gerry (2013). ''A Complete Guide to Reptiles of Australia, Fourth Edition''. Sydney: New Holland Publishers. 522 pp. .

{{Taxonbar, from=Q1429875

Cyclodomorphus
Skinks of Australia
Reptiles described in 1845
Taxa named by John Edward Gray