Hemisphaeriodon
Encyclopedia
Pink-tongued skinks are the genus
Hemisphaeriodon, which contains some of the largest members of the skink
family
(Scincidae). They are called commonly pink-tongued lizards in Australia
, where true lizards (Lacertidae
) do not naturally occur. As suggested by these common names, its distinguishing characteristic is a pink tongue as opposed to the blue tongue of the closely related Tiliqua genus.
", it is a relatively large lizard
of up to 45 cm that has a slender body with a long, slender and slightly prehensile tail
about the same length as the body. The limb
s are well developed with long digit
s and sharp claw
s. The neck
is well pronounced and the head
is relatively large, wider in males than in females. In adult
s the tongue
is pink. H. 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 H. gerrardii are white to pinkish or creamy brown and may be marbled on the cross bands. The scale
s 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 juvenile
s are marked with pronounced black cross bands on a very light grey ground colour. There are several dark spots on their heads, especially under the eyes. The tip of the snout is light in colour and the tongue and mouth are blue. Similar species (Cogger 2000): H. 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). H. gerrardii is very similar in appearance to the Eastern Blue-Tongue, Tiliqua scincoides; however, H. gerrardii has, true to its common name, a pink tongue as an adult. It is also much more slender than the 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. H. gerrardii can be distinguished from the Cyclodomorphus spp. by its relatively shorter body, longer limbs and a much broader head.
forests and rainforest
s as well as moist areas in woodland
s. They shelter beneath leaf litter
, in hollow logs and crevices of rocks and trees and their slender bodies and limbs are an adaptation for moving in thick undergrowth. H. gerrardii move
with lateral undulations on smooth surfaces, but hold their hind limbs close to the body and move the tail in a side-winding motion when moving through grass and when climbing on branches, using only the forelimbs. The lizards’ main diet consists of snail
s and slug
s, for which they forage during twilight
hours and at night in summer and also during the day in cooler months. To crush the shells of snails, H. gerrardii use their large and flattened teeth in the back of the upper and lower jaw
. H. gerrardii are good climbers using their semi-prehensile tail as a supporting aid and, although only partially arboreal, climb trees to feed when necessary. The juveniles seem to climb vegetation more frequently to avoid predation
. When threatened, H. gerrardii raises its body off the ground to appear larger and flickers or vibrates its tongue rapidly similar to snake
s.
, 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 litter
s of 20 to 30 (largest recorded: 67) live-young in early summer. 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.
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...
Hemisphaeriodon, which contains some of the largest members of the skink
Skink
Skinks are lizards belonging to the family Scincidae. Together with several other lizard families, including Lacertidae , they comprise the superfamily or infraorder Scincomorpha...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
(Scincidae). They are called commonly pink-tongued lizards in 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...
, where true lizards (Lacertidae
Lacertidae
Lacertidae is the family of the wall lizards, true lizards, or sometimes simply lacertas, which are native to Europe, Africa, and Asia. The group includes the genus Lacerta, which contains some of the most commonly seen lizard species in Europe...
) do not naturally occur. As suggested by these common names, its distinguishing characteristic is a pink tongue as opposed to the blue tongue of the closely related Tiliqua genus.
Description
Commonly known as a "pink-tongued skinkSkink
Skinks are lizards belonging to the family Scincidae. Together with several other lizard families, including Lacertidae , they comprise the superfamily or infraorder Scincomorpha...
", it is a relatively large 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...
of up to 45 cm that has a slender body with a long, slender and slightly prehensile tail
Prehensile tail
A prehensile tail is the tail of an animal that has adapted to be able to grasp and/or hold objects. Fully prehensile tails can be used to hold and manipulate objects, and in particular to aid arboreal creatures in finding and eating food in the trees...
about the same length as the body. The limb
Limb (anatomy)
A limb is a jointed, or prehensile , appendage of the human or other animal body....
s are well developed with long digit
Digit (anatomy)
A digit is one of several most distal parts of a limb, such as fingers or toes, present in many vertebrates.- Names:Some languages have different names for hand and foot digits ....
s and sharp claw
Claw
A claw is a curved, pointed appendage, found at the end of a toe or finger in most mammals, birds, and some reptiles. However, the word "claw" is also often used in reference to an invertebrate. Somewhat similar fine hooked structures are found in arthropods such as beetles and spiders, at the end...
s. The neck
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...
is well pronounced and the head
Head
In anatomy, the head of an animal is the rostral part that usually comprises the brain, eyes, ears, nose and mouth . Some very simple animals may not have a head, but many bilaterally symmetric forms do....
is relatively large, wider in males than in females. In adult
Adult
An adult is a human being or living organism that is of relatively mature age, typically associated with sexual maturity and the attainment of reproductive age....
s the tongue
Tongue
The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...
is pink. H. 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
Tail
The tail is the section at the rear end of an animal's body; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, reptiles, and birds...
, which run slightly backwards laterally. The ventral surfaces of H. gerrardii are white to pinkish or creamy brown and may be marbled on the cross bands. The scale
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
s are smooth and, on the head, edged with a darker colour. The tip of the snout
Snout
The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...
is dark in adults with some darker spots on the head. The limbs are spotted or streaked darkly. All juvenile
Juvenile (organism)
A juvenile is an individual organism that has not yet reached its adult form, sexual maturity or size. Juveniles sometimes look very different from the adult form, particularly in terms of their colour...
s are marked with pronounced black cross bands on a very light grey ground colour. There are several dark spots on their heads, especially under the eyes. The tip of the snout is light in colour and the tongue and mouth are blue. Similar species (Cogger 2000): H. gerrardii has been associated with the genus Tiliqua as well as the genus Cyclodomorphus
Cyclodomorphus
Cyclodomorphus is a genus of small to medium-sized skinks . It belongs to the Egernia group which also includes the blue-tongued skinks .-Species:*Cyclodomorphus branchialis...
due to their close relation (previous names: Cyclodomorphus gerrardii and Tiliqua gerrardii). H. gerrardii is very similar in appearance to the Eastern Blue-Tongue, Tiliqua scincoides; however, H. gerrardii has, true to its common name, a pink tongue as an adult. It is also much more slender than the 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. H. gerrardii can be distinguished from the Cyclodomorphus spp. by its relatively shorter body, longer limbs and a much broader head.
Range
From Springwood, NSW, along the eastern coastal country and eastern ranges to the Cairns region, QLDEcology and behaviour
H. gerrardii inhabit wet sclerophyllSclerophyll
Sclerophyll is the term for a type of vegetation that has hard leaves and short internodes . The word comes from the Greek sclero and phyllon ....
forests and rainforest
Rainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
s as well as moist areas in woodland
Woodland
Ecologically, a woodland is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses. Woodland may form a transition to shrubland under drier conditions or during early stages of...
s. They shelter beneath leaf litter
Plant litter
Plant litter, leaf litter or tree litter is dead plant material, such as leaves, bark, needles, and twigs, that has fallen to the ground. Litter provides habitat for small animals, fungi, and plants, and the material may be used to construct nests. As litter decomposes, nutrients are released to...
, in hollow logs and crevices of rocks and trees and their slender bodies and limbs are an adaptation for moving in thick undergrowth. H. gerrardii move
Animal locomotion
Animal locomotion, which is the act of self-propulsion by an animal, has many manifestations, including running, swimming, jumping and flying. Animals move for a variety of reasons, such as to find food, a mate, or a suitable microhabitat, and to escape predators...
with lateral undulations on smooth surfaces, but hold their hind limbs close to the body and move the tail in a side-winding motion when moving through grass and when climbing on branches, using only the forelimbs. The lizards’ main diet consists of snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s and slug
Slug
Slug is a common name that is normally applied to any gastropod mollusc that lacks a shell, has a very reduced shell, or has a small internal shell...
s, for which they forage during twilight
Twilight
Twilight is the time between dawn and sunrise or between sunset and dusk, during which sunlight scattering in the upper atmosphere illuminates the lower atmosphere, and the surface of the earth is neither completely lit nor completely dark. The sun itself is not directly visible because it is below...
hours and at night in summer and also during the day in cooler months. To crush the shells of snails, H. gerrardii use their large and flattened teeth in the back of the upper and lower jaw
Jaw
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...
. H. gerrardii are good climbers using their semi-prehensile tail as a supporting aid and, although only partially arboreal, climb trees to feed when necessary. The juveniles seem to climb vegetation more frequently to avoid predation
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
. When threatened, H. gerrardii raises its body off the ground to appear larger and flickers or vibrates its tongue rapidly similar to 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.
Breeding biology
Courtship occurs in early spring for a period of six weeks, during which time males have been observed to fight. In matingMating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
, the male grasps the female’s head with his jaws and mounts her. After an estimated gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period of 101 to 110 days, females produce large litter
Litter (animal)
A litter is the offspring at one birth of animals from the same mother and usually from one set of parents. The word is most often used for the offspring of mammals, but can be used for any animal that gives birth to multiple young. In comparison, a group of eggs and the offspring that hatch from...
s of 20 to 30 (largest recorded: 67) live-young in early summer. During birth
Birth
Birth is the act or process of bearing or bringing forth offspring. The offspring is brought forth from the mother. The time of human birth is defined as the time at which the fetus comes out of the mother's womb into the world...
, 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
Amnion
The amnion is a membrane building the amniotic sac that surrounds and protects an embryo. It is developed in reptiles, birds, and mammals, which are hence called “Amniota”; but not in amphibians and fish , which are consequently termed “Anamniota”. The primary role of this is the protection of the...
, 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
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
is about 22 months.
Further reading
- Cogger, H. G. 2000. Reptiles and Amphibians of Australia. Reed New Holland, Sydney, NSW.
- Greer, A. E. 1989. The Biology and Evolution of Australian Lizards. Surrey Beatty & Sons, Chipping Norton, NSW.
- Healey, J. 1997. The Reader’s Digest Encyclopaedia of Australian Wildlife. Reader’s Digest, Australia
- Longley, G. 1938. Notes on a pink tongued skink (Hemisphaeriodon gerrardii). Proceedings of the Royal Zoological Society of NSW 1937-1938:19-21.
- Macleay, W. 1885. On some reptilia lately received from the Herbert River District,
- Queensland. The Proceedings of the Linnean Society of NSW 10:64-68
- Mitchell, F. J. 1951. The scincid genera Egernia and Tiliqua (Lacertilia). Records of the South Australian Museum 9:275-308.
- Shea, G. 1982. Observations on some members of the genus Tiliqua. Herpetofauna 13(2):18-20
- Wilhoft, C. W. 1960. Observations on adults and juveniles of Hemisphaeriodon gerrardii in captivity. North Queensland Naturalist 28:3-4.