Skinks (Scincidae)
Skinks
(Scincidae)
Class Reptilia
Order Squamata
Suborder Sauria
Family Scincidae
Thumbnail description
Tiny to moderately large lizards, both limbed and limbless, usually with smooth scales
Size
0.9–19.3 in (23–490 mm) in snout-vent length
Number of genera, species
126+ genera; about 1,400 species
Habitat
Versatile
Conservation status
Extinct: 3 species; Critically Endangered: 2 species; Endangered: 3 species; Vulnerable: 21 species; Lower Risk/Near Threatened: 5 species; Data Deficient: 7 species
Distribution
Cosmopolitan, except at high elevations and latitudes
Evolution and systematics
With well over 100 genera and more than 1,400 species, skinks are by far the largest family of lizards, an exceedingly diverse group. Their diversity is evident in all aspects of their biology. Terrestrial, arboreal, fossorial, and even semiaquatic skinks exist. Skinks have radiated to fill niches in all types of environments, including arid deserts, savannas, lowland rain-forests, temperate forests, and cool montane habitats. Some skinks are diminutive, but others are large. These lizards vary in morphologic characteristics from short and robust with strong, well-developed limbs to elongated and fragile with tiny or no vestigial limbs. In some arid regions (e.g., Australia), they dominate the lizard fauna; in others, such as the Sonoran and Great Basin Deserts, they are essentially absent. Skinks have dispersed widely, many having rafted across oceans to colonize other continents and even remote islands in the Pacific. Four subfamilies are recognized; one (Scincinae) is probably not monophyletic but rather a paraphyletic group:
Acontinae
This is a subfamily of moderately large, limbless, fossorial skinks found in South Africa. There are three genera and 17 species. They are derived from unknown scincine ancestors.
Feylininae
This subfamily comprises moderate to large limbless skinks that inhabit tropical western and central Africa. There is one genus with six species. They are derived from unknown scincine ancestors.
Lygosominae
These skinks are very diverse, ranging from small to large, advanced skinks. They are found worldwide, with more than 82 genera and about 900 species.
Scincinae
This diverse subfamily occurs in North America, Africa, southwest Asia, southern Asia, eastern Asia, and the Philippines. There are more than 30 genera, with more than 300 species.
Scincinae is not a natural group but is based on shared ancestral characters and probably does not contain all descendents of a common ancestor (i.e., it is paraphyletic). Scincines are primitive skinks with smooth cylindrical bodies and small legs. The scincine genus Eumeces displays several important ancestral character states, which could resemble the common ancestral state for all skinks. Other candidates for basal scincids include certain African and Asian scincines (Brachymeles and Chalcides).
Both acontines and feylinines appear to be derived from scincine ancestors. Acontines (Acontias, Acontophiops, and Typhlosaurus), found in Africa, are specialized legless burrowing skinks found only in leaf litter and loose, sandy soil or underneath logs. The small subfamily Feylininae contains a single genus, Feylinia, consisting of six species, also burrowers, from central tropical Africa.
By far the largest subfamily is the Lygosominae, with more than 80 genera and more than 900 species. Lygosomines are derived, highly advanced skinks, with five distinct and presumably monophyletic lineages: the Egernia group, the Lygosoma group, the Mabuya group, the Sphenomorphus group, and the Eugongylus group. Most of these groups occur in Australia (a major center for skink diversity). Some members of each group also occur outside Australia, especially in New Guinea and New Caledonia. Exactly where Lygosoma and Mabuya (a paraphyletic genus) and several other Old World lygosomines
should be placed within Lygosominae remains uncertain. New skink genera are still being described.
Physical characteristics
All skinks presumably derived from a single common ancestor (i.e., they are monophyletic). They have large, symmetric, shieldlike scales on the head. Most skinks have smooth, glossy, circular scales, but a few have sharp or keeled scales. Bony plates, known as osteoderms, underlie skink scales. One distinctive feature of skinks is the bony secondary palate in the roof of the mouth, which separates the respiratory and digestive passages. (These are confluent in most other lizards.) Other lizards pant when they are thermally stressed (which cools the roof of the mouth, into which large blood sinuses can dissipate heat), but skinks do not pant, perhaps because the secondary palate impedes heat exchange.
Skinks have repeatedly evolved reduced appendages; numerous different evolutionary groups have produced completely limbless forms (Acontias, Anomalopus, Barkudia, Brachymeles, Coeranoscincus, Feylinia, Lerista, Melanoseps, Ophiomorus, Ophioscincus, Scelotes, Scolecoseps, Sepsophis, Typhlacontias, and Typhlosaurus). These 15 genera are found in Africa, Asia, and Australia. A single North American genus, Neoseps, approaches limblessness, with both front and hind limbs reduced to tiny appendages. The same is true of many skinks in Southeast Asia (e.g., species of Larutia and Riopa). Legless skinks, as well as those with reduced limbs, are typically burrowers and usually have small eyes and consolidated head shields. All degrees of limb reduction can occur within a single genus.
In most lizards, including some skinks, inguinal fat bodies protrude into the abdominal cavity from the pelvic area. (These store valuable energy reserves used in reproduction.) Members of the large Sphenomorphus group of skinks, however, have lost these fat bodies and rely on their tails to store fat. Tail loss thus can be costly. In many skinks, the tails of juveniles are markedly brighter than the tails of adults. Red, blue, and yellow tails are thought to lure the attention of predators away from the body.
Skinks have a wide variety of eye types. As in other lizards, only the lower eyelid moves; it is lowered to open the eye and raised to close it. The ancestral condition is a freely movable, scaly, opaque eyelid. Several other derived states exist among skinks: some species have a freely movable eyelid with a clear, disclike central scale, or window, through which the lizard can see even when the eye is closed. In other species of skinks the eyelid is fused immovably in the raised position, with an expanded clear area through which they can see. Still other skinks have a clear eyelid fused all around, forming a spectacle similar to those of geckos and snakes. Larger skinks tend to display the ancestral condition, with movable, opaque eyelids, but most smaller skink species have more derived eyelid conditions. Permanently capped eyes in small skinks limit evaporative water loss and protect the eye.
Distribution
Skinks are cosmopolitan, occurring on all continents except Antarctica as well as on many oceanic islands. They have colonized the New World only a handful of times. As a result, only a few genera are represented (e.g., Eumeces, Mabuya, Neoseps, Scincella, and Sphenomorphus). Nevertheless, two genera have been particularly successful, the scincine Eumeces in North America and the lygosomine Mabuya in South America. About 30 species of Eumeces and 15 species of Mabuya are found in the New World. Both genera are also represented in the Old World.
Habitat
Skinks may be terrestrial, fossorial, or arboreal. Some skinks (Amphiglossus astrolabi, Eulamprus quoyi, and Tropidophorus grayi) are actually semiaquatic.
Behavior
Skinks have adopted a wide variety of habits. Most are diurnal, but others, such as some species of Egernia and Eremiascincus, are nocturnal. Many North American skinks, especially Eumeces, are secretive, spending much of their time under fallen logs or rocks; thus, they are not very conspicuous. Central and South American skinks (Mabuya and Sphenomorphus) are active during the day and frequently are observed basking or foraging. In some parts of Africa and Australia, skinks are very conspicuous and diverse, being active during the heat of midday, often in very arid areas.
Almost all skinks exploit tail autotomy as a means of escape from predators, although a few skinks, such as some species of Egernia, Corucia, and Tiliqua, do not shed their tails. Some Egernia species have flattened, spiny tails, which are used to block off entrances to their crevice retreats. Australian Ctenotus and North American Scincella sometimes return to the site where their tails were lost and swallow the remains of them. Few, if any, other vertebrates display auto-amputation and self-cannibalism.
Visual cues are used in individual discrimination, particularly the choice of mate, as well as in prey discrimination. Skinks have exceedingly well developed olfactory abilities and can recognize and determine species, sex, and sexual receptivity of other individuals by scent. They also can detect predators and discriminate prey on the basis of chemical cues.
All skinks possess bony plates within their scales, known as osteoderms, which are composed of compound plates of several interconnected bones underneath each scale. Scales overlap in the fashion of shingles on a roof. Such body armor doubtless confers protection from predators. One pygopodid lizard and several species of snakes have evolved hinged teeth to facilitate obtaining a firm grip on their skink prey. (Hinged teeth fold when they hit an osteoderm.) Indeed, if a skink struggles backward during ingestion, the teeth lock into place. Skinks are swallowed rapidly, suggesting that they might actually facilitate their own ingestion, crawling away from the ratchet-like teeth down a predator's gullet. Some skinks have very loose skin and scales that tear away when they are attacked by predators, allowing for escape.
Feeding ecology and diet
Skinks are active, widely foraging predators. Most skinks are insectivorous, but a few large Australian species (Tiliqua) are omnivorous. Some burrowing species, such as Lerista and Typhlosaurus, feed largely on termites.
Reproductive biology
Live bearing (viviparity) has arisen many times among skinks, although many species retain the ancestral condition and lay eggs (oviparity). In two Australian species of skinks (Lerista bougainvillii and Saiphos equalis), both egg laying and live bearing occur among different populations within each species. Brood sizes vary greatly among skinks, from one to two in some species (such as Lobulia and Prasinohaema, which appear to have a fixed clutch size, as in anoles and geckos) to 53 or even 67 in others (such as the Australian Tiliqua gerrardii). Some skinks lay their eggs in communal nests, which could be an indication that suitable nest sites are in short supply. This behavior also could represent repeated use by one or more females of nest sites with a history of high hatching success.
Some viviparous skinks give birth to a single, extremely large neonate (Corucia zebrata, Tiliqua rugosa, and Typhlosaurus gariepensis). Within viviparous skinks, the entire range of fetal nutritional types occurs. Many species ovulate large eggs containing all the nutrients necessary for development; thus, developing offspring feed on their own yolk (lecithotrophy, ovoviviparity) before being born alive. Various degrees of placental development take place, in which nutrients are passed from mother to offspring (matrotrophy) during development. For example, Chalcides have complex placental connections between mother and progeny through which pass substantial amounts of nutrients required for development. Still other species, such as Mabuya heathi in Brazil, have an advanced placental arrangement, passing more than 99% of nutrients necessary for neonatal development from the mother through a placenta.
Conservation status
Most species of skinks are not threatened, but a few, especially island forms, are threatened. The IUCN lists 41 species, 3 as Extinct, 2 as Critically Endangered, 3 as Endangered, 21 as Vulnerable, 5 as Lower Risk/Near Threatened, and 7 as Data Deficient.
Significance to humans
Skinks are important insectivores in many natural habitats. Some large species, such as Corucia, are commonly kept as pets. Others were once considered to have medicinal value.
Species accounts
List of Species
Striped blind legless skinkPrehensile-tailed skink
Fourteen-lined comb eared skink
Cyclodomorphus branchialis
Night skink
Broad-banded sand swimmer
Prickly forest skink
Striped skink
Menetia greyii
Bobtail
Broad-headed skink
Sandfish
Striped blind legless skink
Typhlosaurus lineatus
subfamily
Acontinae
taxonomy
Typhlosaurus lineatus Boulenger, 1887, Cape of Good Hope, Africa. Four subspecies are recognized.
other common names
None known.
physical characteristics
This is a small, legless, blind skink with a shovel-nosed snout and countersunk lower jaw. The eyes are vestigial. The hard, smooth body is yellowish, reddish, or black, with varying numbers of dark longitudinal stripes and a short blunt tail.
distribution
The species occurs in the Kalahari Desert and adjoining areas.
habitat
It inhabits sandveld semidesert.
behavior
These subterranean fossorial skinks burrow just beneath the surface, often under logs and fallen debris.
feeding ecology and diet
These skinks are termite specialists.
reproductive biology
Females give birth to two to three living young in mid-January through early March.
conservation status
Not threatened.
significance to humans
None known.
Prehensile-tailed skink
Corucia zebrata
subfamily
Lygosominae
taxonomy
Corucia zebrata Gray, 1855, Makira Island (San Cristobal), Solomon Islands.
other common names
None known.
physical characteristics
This big skink has a large head, well-developed and strongly clawed limbs, a robust body, and a prehensile tail. The lower eyelid is scaly. It has no supranasals; the prefrontals are narrowly separated or in contact, and the parietals are widely separated. The dorsal ground color varies, ranging from khaki to
gray-green to pale olive green, with lighter and darker flecks dorsally. Rostral and nasal scales, often the frontonasal scales, are cream or light yellow. The tail is olive green or brown, without markings. The ventral color is yellow-green to light gray-green. The iris is golden yellow to lime green.
distribution
The species is endemic to the Solomon Islands: Bougainville, Shortland Islands, Choiseul, Vella Lavella, New Georgia, Isabel, Guadalcanal, Ngela, Malaita, Makira, Ugi, and Santa Ana.
habitat
This large skink is fairly common, but because it is nocturnal, sheltering during the day in hollows or among dense foliage in the larger forest trees, it is seldom seen. Its preferred habitat is the strangler fig tree (Ficus sp.). These lizards are almost completely arboreal, though they occasionally are encountered on the ground, moving between trees at night.
behavior
These skinks are nocturnal. They possess strongly prehensile tails and are excellent climbers. They move slowly and usually are docile, though when provoked, they will rise up and exhale with a sharp, loud hiss through the open mouth. If tormented, they bite savagely, given the opportunity. After rains that follow a prolonged drought, these skinks emerge at dusk from fig tree hollows to lick up raindrops collected on leaves of their host tree.
feeding ecology and diet
This skink is completely herbivorous and consumes a variety of plants, but the bulk of its diet is made up of leaves and flowers of the aroid Epipremnum pinnatum.
reproductive biology
Live bearers, these skinks give birth to single, large young about one-third the size of adults. Twins are rare. Newborns eat the fecal pellets of adults to establish the gut flora necessary for digestion of plant material.
conservation status
The species has been overcollected in the Solomons by animal dealers, to supply the foreign pet trade. It is listed on Appendix II of CITES. Thousands are exported from the Solomons each year, seriously threatening the long-term survival of wild populations of this spectacular skink. It is not listed by the IUCN.
significance to humans
Rural Solomon Islanders prize this lizard as food. Many are kept in captivity by herpetoculturists around the world.
Fourteen-lined comb eared skink
Ctenotus quattuordecimlineatus
subfamily
Lygosominae
taxonomy
Ctenotus quattuordecimlineatus Sternfeld, 1919, Hermannsburg Mission, Upper Finke River, Northern Territory.
other common names
None known.
physical characteristics
These relatively small, sleek diurnal skinks have 14 pale longitudinal lines on a darker body background. In all species of Ctenotus, which translates "comb ear," several scales protrude backward on the anterior edge of the external ear opening.
distribution
The species occurs in central Australia.
habitat
These skinks inhabit red, sandy deserts with spinifex grasses.
behavior
These alert, wary, active, diurnal skinks are constantly on the move between grass tussocks.
feeding ecology and diet
This skink forages widely, constantly moving from tussock to tussock and searching for insect prey, particularly termites.
reproductive biology
Females lay two to four eggs. The average clutch size is three eggs.
conservation status
Not threatened.
significance to humans
None known.
No common name
Cyclodomorphus branchialis
subfamily
Lygosominae
taxonomy
Cyclodomorphus branchialis Gunther, 1867, Champion Bay, Western Australia.
other common names
None known.
physical characteristics
This is a moderately sized, elongated, slender, short-limbed skink. The color varies from gray to olive brown, sometimes greenish and occasionally dotted with white or cream spots, especially in juveniles. The tail is slightly less than or about equal to the snout to vent length.
distribution
It occurs in Western and South Australia, the southern portion of the Northern Territory, and western Queensland.
habitat
This skink inhabits semiarid heaths, woodlands, shrublands, coastal dunes, and red, sandy deserts vegetated with spinifex grasses.
behavior
In sandy deserts these secretive lizards spend most of their time within large Triodia grass tussocks. In other habitats, they hide in leaf litter or under fallen bushes and trees. They are crepuscular and nocturnal.
feeding ecology and diet
The species feeds primarily on a variety of arthropods but also occasionally eats snails and small lizards.
reproductive biology
These are live bearers, typically with litter sizes of two to three large young.
conservation status
Not threatened.
significance to humans
None known.
Night skink
Egernia striata
subfamily
Lygosominae
taxonomy
Egernia striata Sternfeld, 1919, Hermannsburg Mission, Upper Finke River, Northern Territory.
other common names
English: Nocturnal desert skink.
physical characteristics
These are moderately large, reddish brown terrestrial skinks with elliptical pupils.
distribution
The species occurs in Central Australia.
habitat
The night skink inhabits red, sandy deserts with spinifex grass.
behavior
This large nocturnal skink digs elaborate tunnel systems that are used as retreats by many other species of reptiles, both diurnal and nocturnal. These complex burrows are important features of Australian sandy deserts, with several interconnected openings often as far as 3.3 ft (1 m) apart and up to 1.6 ft (0.5 m) deep, vaguely reminiscent of a tiny rabbit warren.
Most sand removed from a night skink burrow is piled up in a large mound outside one "main" entrance.
feeding ecology and diet
The major prey is termites, which constitute 76% of the diet by volume. Beetles, ants, cockroaches, and insect larvae also are eaten.
reproductive biology
Night skinks are live bearers, giving birth to one to four young. Gravid females with full-term embryos are found from late October through mid-January (with a peak in December). Juveniles stay in the same burrow system with their mothers, as they often contain an adult female plus several newborn young.
conservation status
Not threatened.
significance to humans
These skinks consume insects.
Broad-banded sand swimmer
Eremiascincus richardsonii
subfamily
Lygosominae
taxonomy
Eremiascincus richardsonii Gray, 1845, Houtman's Abrolhos, Western Australia.
other common names
None known.
physical characteristics
These are medium-size yellow-golden brown skinks, with eight to 14 blackish bands on the body and about 20 bands on the tail.
distribution
The species is found throughout most of interior Australia, but not along the eastern, northern, and southern coasts.
habitat
They inhabit semihumid to arid areas, including hard or stony substrates with woodlands, shrublands, and hummock grasslands. They also are found throughout the red, sandy deserts of central Australia.
behavior
These skinks are crepuscular, nocturnal, and terrestrial. They frequent burrows, often digging their own small burrows off at a right angle to larger burrows, such as a rabbit warrens.
feeding ecology and diet
The species feeds on beetles, ants, wasps, and termites.
reproductive biology
Little is known about their reproduction, but they lay from three to seven eggs.
conservation status
Not threatened.
significance to humans
None known.
Prickly forest skink
Gnypetoscincus queenslandiae
subfamily
Lygosominae
taxonomy
Gnypetoscincus queenslandiae De Vis, 1890, Bellendenker and Herberton, Queensland.
other common names
None known.
physical characteristics
This small skink is brownish to purple-brown with small keeled scales. The bizarre granular scales and coarse skin appear to help keep the skin evenly moist through capillary spread along the edges of the scales.
distribution
The species is found only in rainforest along the northeastern Queensland coast, from Rossville south to Kirrama.
habitat
The prickly forest skink inhabits rainforest.
behavior
These skinks shun direct sunlight, and they shelter under rotting logs, stones, and leaf litter deep in rainforest, where damp, shaded conditions prevail. These cryptic skinks have low active body temperatures.
feeding ecology and diet
Little is known about the diet, but slugs, snails, and worms are probable food items.
reproductive biology
Litters of one to two young are born throughout the year.
conservation status
Not threatened.
significance to humans
None known.
Striped skink
Mabuya striata
subfamily
Lygosominae
taxonomy
Mabuya striata Peters, 1844, Mozambique. Four subspecies are recognized.
other common names
None known.
physical characteristics
The color of this medium-size arboreal skink is dark blackish in the Kalahari, but it varies regionally between subspecies.
distribution
The species is widespread in southern Africa, including extreme southern Angola and Zambia, Namibia, Botswana, Zimbabwe, Mozambique, and parts of central and eastern South Africa.
habitat
The habitat is varied; these skinks are found in woodlands, deserts, and mangrove swamps.
behavior
This alert climbing skink is found on trees in the Kalahari Desert. It maintains a higher body temperature during the summer than in the winter and basks early and late in the day during summer but at midday in winter.
feeding ecology and diet
The diet is composed of a broad variety of insects, including beetles, termites, ants, insect larvae, and spiders.
reproductive biology
In northern populations, breeding males have orange-brown heads and yellow-orange throats. The striped skink is live bearing, with an average litter size of 5.4.
conservation status
Not threatened.
significance to humans
None known.
No common name
Menetia greyii
subfamily
Lygosominae
taxonomy
Menetia greyii Gray, 1845, Australia.
other common names
None known.
physical characteristics
These tiny bronze-brown to gray-brown skinks have narrow, broken, dark lines from the neck to the base of the tail. The limbs are short, with four toes on the forelimbs and five toes on the hind limbs.
distribution
The species occurs through most of Australia.
habitat
These skinks are versatile, occurring in a wide range of habitats, including sandy spinifex deserts, shrub acacia woodland, mallee, dry sclerophyll forests, and temperate and tropical woodlands. They are largely absent from rainforest.
behavior
These tiny diurnal lizards are denizens of leaf litter.
feeding ecology and diet
These skinks prey on small termites, spiders, and hemipterans.
reproductive biology
Males have an orange throat and yellow venter during the breeding season. Both sexes mature during their first year, and some live to breed again in their second year. Females can produce two clutches of one to three eggs per season. Neonates measure only 0.79 in (2 cm) and weigh only 0.004 oz (0.1 g).
conservation status
Not threatened.
significance to humans
None known.
Bobtail
Tiliqua rugosa
subfamily
Lygosominae
taxonomy
Tiliqua rugosa Gray, 1825, type locality not specified. There are four subspecies.
other common names
English: Shingleback, sleepy lizard, boggi.
physical characteristics
This large lizard is recognized easily by its short, blunt tail and shingle-like scales. The color varies, ranging from white to dark gray to reddish.
distribution
The species occurs in southern Australia, central New South Wales, and southern Queensland.
habitat
Bobtails are found in all terrestrial habitats, including sclerophyll forests, hummock grasslands, chenopod shrublands, mallee, and sparsely vegetated coastal dunes, but it is uncommon in dense forests and swamps.
behavior
These are slow-moving, lethargic lizards. When threatened, they open their mouths wide and wave their blue tongues. They often bask on roads, where many are killed by passing vehicles.
feeding ecology and diet
Bobtails are omnivorous.
reproductive biology
These lizards form long-term pair bonds. Females give birth to two very large young (rarely, one or three young).
conservation status
Not threatened.
significance to humans
Bobtails may be kept as pets.
Broad-headed skink
Eumeces laticeps
subfamily
Scincinae
taxonomy
Eumeces laticeps Schneider, 1801.
other common names
English: Scorpion, greater five-lined skink; French: Euméces à tête large; German: Breitkopfskink.
physical characteristics
These are moderately large, brown skinks. Males have reddish heads during the breeding season.
distribution
The species is widespread in the southeastern United States, from eastern Texas north through eastern Oklahoma and eastern
Kansas to southern Missouri. They occur in Illinois, Indiana, and Ohio, east to Maryland, Delaware, and New Jersey and south to northern Florida. They also are found throughout Kentucky, Virginia, Tennessee, North Carolina, South Carolina, Georgia, Alabama, Mississippi, Louisiana, and Arkansas.
habitat
Broad-headed skinks inhabit swamps, woodlands, forests, and urban lots strewn with debris.
behavior
These skinks are strongly arboreal, adeptly climbing trees and fences. They operate at relatively low body temperatures but are wary, sleek, and slippery lizards.
feeding ecology and diet
These active, widely foraging skinks consume a wide variety of arthropods.
reproductive biology
In Florida, mating occurs in April and May, but it is somewhat later further north. During the breeding season, males have red heads, which are used as displays in male-male combat as well as in courtship of females. Males face off, moving in a circle; lunge at each other; and aggressively bite the head, neck, and tail of the other male. Tail loss and wounds on the head and neck result, and eventually the loser retreats. Males fight over females, chasing each other up and down trees. Females deposit six to 10 eggs and usually guard their clutches until they hatch.
conservation status
Not threatened.
significance to humans
None known.
Sandfish
Scincus scincus
subfamily
Scincinae
taxonomy
Scincus scincus Linnaeus, 1759, North Africa. Four subspecies are recognized.
other common names
French: Poisson des sables, Scinque des sables; German: Apothekerskink, Sandfisch.
physical characteristics
These medium-size, pale-colored, banded, fusiform skinks have shovel-shaped snouts, countersunk lower jaws, short tails, and enlarged toe lamellae forming fringes along the toes that enhance traction on loose sand.
distribution
The sandfish occurs in the Sahara of northern Africa, from Algeria, Tunisia, and Libya to Egypt and the Mediterranean coast. It also is found in Israel, Jordan, Iraq, and Iran.
habitat
These skinks inhabit areas with loose, drifting sand and rich vegetation on the leeward sides of dunes, where sands are not exposed to drying winds. They are found around oases.
behavior
These lizards escape from enemies by running along the surface and then suddenly diving into loose sand and swimming a short distance, leaving behind a clear mark where they entered the sand.
feeding ecology and diet
The sandfish sometimes swims in loose sand and captures insects on the surface from below. They are omnivorous, preying on scorpions, beetles, other insects, and insect larvae as well as flowers and grains. Occasionally, they eat small Acanthodactylus lizards.
reproductive biology
Males reach larger sizes than females. Mating occurs in June, and females lay about six eggs shortly thereafter.
conservation status
Not threatened.
significance to humans
The species once was considered to be a source for a medicinal pharmaceutical against many ailments as well as an aphrodisiac. Dried specimens wrapped in wormwood (Artemesia) were imported into Europe via Cairo until the last century. The belief in their medicinal effects seems to have been based on the fact that they feed on wormwood, which is known to have medicinal properties. They are eaten by locals.
Resources
Books
Greer, Allen E. The Biology and Evolution of Australian Lizards. Chipping Norton, Australia: Surrey Beatty and Sons, 1989.
Hutchinson, M. N. "Family Scincidae." In Fauna of Australia. Vol. 2A, Amphibia and Reptilia, edited by C. J. Gasby, C. J. Ross, and P. L. Beesly. Canberra: Australian Biological and Environmental Survey, 1993.
Hutchinson, M. N., and S. C. Donnellan. "Phylogeny and Biogeography of the Squamata." In Fauna of Australia. Vol. 2A, Amphibia and Reptilia, edited by C. J. Gasby, C. J. Ross, and P. L. Beesly. Canberra: Australian Biological and Environmental Survey, 1993.
Pianka, E. R. Ecology and Natural History of Desert Lizards: Analyses of the Ecological Niche and Community Structure. Princeton, NJ: Princeton University Press, 1986.
Pianka, E. R., and L. J. Vitt. Lizards: Windows to the Evolution of Diversity. Berkeley: University of California Press, 2003.
Storr, G. M., L. A. Smith, and R. E. Johnstone. Lizards of Western Australia. Vol. 1, Skinks. Perth: Western Australian Museum, 1999.
Zug, George R., Laurie J. Vitt, and Janalee P. Caldwell. Herpetology: An Introductory Biology of Amphibians and Reptiles. 2nd edition. San Diego: Academic Press, 2001.
Periodicals
Greer, A. E. "Distribution of Maximum Snout-Vent Length Among Species of Scincid Lizards." Herpetology 35, no. 3 (2001): 383–395.
Huey, R. B., and E. R. Pianka. "Patterns of Niche Overlap Among Broadly Sympatric Versus Narrowly Sympatric Kalahari Lizards (Scincidae: Mabuya)." Ecology 58 (1977): 119–128.
——. "Seasonal Variation in Thermoregulatory Behavior and Body Temperature of Diurnal Kalahari Lizards." Ecology 58 (1977): 1066–1075.
Huey, R. B., E. R. Pianka, M. E. Egan, and L. W. Coons. "Ecological Shifts in Sympatry: Kalahari Fossorial Lizards (Typhlosaurus)." Ecology 55 (1974): 304–316.
Pianka, E. R., and W. F. Giles. "Notes on the Biology of Two Species of Nocturnal Skinks, Egernia inornata and Egernia striata, in the Great Victoria Desert." Western Australian Naturalist 15 (1982): 44–49.
Vitt, L. J., and W. E. Cooper Jr. "The Evolution of Sexual Dimorphism in the Skink Eumeces laticeps: An Example of Sexual Selection." Canadian Journal of Zoology 63 (1985): 995–1002.
——. "Feeding Responses of Broad-Headed Skinks (Eumeces laticeps) to Velvet Ants (Dasymutilla occidentalis)." Journal of Herpetology 22 (1988): 485–488.
——. "The Relationship Between Reproduction and Lipid Cycling in Eumeces laticeps with Comments on Brooding Ecology." Herpetologica 41 (1985): 419–432.
Other
McCoy, Mike. Reptiles of the Solomon Islands. CD-ROM. Kuranda, Australia: Zoo Graphics, 2000.
Eric R. Pianka, PhD