The Mallee Worm-lizard (Aprasia inaurita), also known as the Pink-nosed Worm-lizard and the Red-tailed Worm-lizard, is a slender pygopid (legless lizard) species that is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, with recorded distribution across the four southern mainland states, although, its

distribution Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations * Probability distribution, the probability of a particular value or value range of a vari ...

is restricted in

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 ...

and

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 ...

.Office of Environment and Heritage (OEH). 2017. Mallee Worm-lizard profile. https://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10060

Description

The Mallee Worm-lizard (''Aprasia inaurita'') is identifiable by its pale olive brown or greyish-brown colouring from above, a whitish underside, with a reddish-brown hue around the Mallee Worm-lizard’s head and neck and a distinguishably bright reddish-orange tail. The Mallee Worm-lizard also lacks an external ear opening and has very small black eyes, with the lack of an external ear opening being what distinguishes Aprasia inaurita with Aprasia aurita – the eared worm-lizard, which is also confusingly known as the Mallee Worm-lizard in the state of

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 ...

. The Mallee Worm-lizard has a snout-vent length of 135mm, with studies upon body length of the species finding that females were larger than males, with the average female body size around 115.6mm and the average male body length around 101.6mm.Webb, J. K. Shine, R. 1994. Feeding habits and reproductive biology of Australian Pygopodid lizards of the genus Aprasia. ''American Society of Ichthyologists and Herpetologists (ASIH), 1994(''2), 390-398. The same study also found that males were more common than females but this may have been attributed to the time of the year the study was conducted. Aprasia inaurita is differentiated from other

Aprasia ''Aprasia'' is a genus of lizards in the family Pygopodidae. The genus is endemic to Australia. The species in the genus ''Aprasia'' are worm-like, burrowing lizards. At least four of the species are oviparous. Species The genus ''Aprasia'' cont ...

by: * The dorsal surface of the head and body being uniformly pigmented with a faint lateral head pattern rarely present.Kluge, A. G. 1974. A taxonomic revision of the lizard family Pygopodidae. University of Michigan Museum of Zoology. Report No. 147. * The nasal and first subpralabial scales being distinct posterior to nostril and the nasal contacts the second supralabial. * Containing two or three postorbital scales and usually 10 nuchal scales. * Containing 14 midbody scale rows with usually 3 preanal scales. * Containing ventral scales averaging 149.7 in males and 154.6 in females.

Habitat

The Mallee Worm-lizard inhabits

semi-arid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-ar ...

areas of red sandy soils and

woodlands Woodlands may back refer to: * Woodland, a low-density forest Geography Australia * Woodlands, New South Wales * Woodlands, Ashgrove, Queensland, a heritage-listed house associated with John Henry Pepper * Woodlands, Marburg, Queensland, a her ...

of the Mallee region and surrounds. Thought to be dependent on Spinifex (''

Triodia scariosa ''Triodia scariosa'', is more commonly known as porcupine grass or spinifex (not to be confused with '' Spinifex spp.''), and belongs to the endemic Australian grass genus'' Triodia.'' The species is perennial and evergreen and individuals grow ...

''), the Mallee Worm-lizard is often found sheltering in sand, beneath mallee stumps, through leaf litter, or as a

fossorial A fossorial () animal is one adapted to digging which lives primarily, but not solely, underground. Some examples are badgers, naked mole-rats, clams, meerkats, and mole salamanders, as well as many beetles, wasps, and bees. Prehistoric eviden ...

species inhabiting ant tunnels.Shea, G. M. 1983. Family Pygopodidae; In Glasby, C. G. Ross, G. J. B. Beesley, P. L. (Eds.). Fauna of Australia – Volume 2a Amphibia and Reptilia. AGPS Canberra. The Mallee Worm-lizard is also said to require mature habitats with a well-developed surface

debris Debris (, ) is rubble, wreckage, ruins, litter and discarded garbage/refuse/trash, scattered remains of something destroyed, or, as in geology, large rock fragments left by a melting glacier, etc. Depending on context, ''debris'' can refer to ...

layer.Adam, P. 2004. Mallee worm-lizard (Aprasia inaurita) – endangered species listing. NSW Department of Plannning and Environment. https://www.environment.nsw.gov.au/topics/animals-and-plants/threatened-species/nsw-threatened-species-scientific-committee/determinations/final-determinations/2004-2007/mallee-worm-lizard-aprasia-inaurita-endangered-species-listing To burrow through loose soil and to crawl through narrow earth cracks and insect tunnels,

species use lateral undulations for locomotion.

Ecology

The

genera are a

myrmecophagous Myrmecophagy is a feeding behavior defined by the consumption of termites or ants, particularly as pertaining to those animal species whose diets are largely or exclusively composed of said insect types. Literally, myrmecophagy means "ant eating" ...

species, with the Mallee Worm-lizard specifically targeting the

Aphaenogaster ''Aphaenogaster'' is a genus of myrmicine ants. About 200 species have been described, including 18 fossil species. They occur worldwide except in South America south of Colombia, sub-Saharan Africa, and Antarctica. They are often confused w ...

sp. eggs and

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

e.Jones, S. R. 1999. Conservation biology of the Pink-tailed legless lizard – Aprasia parapulchella. University of Canberra Applied Ecology Research Group. Webb & Jones (1994) state that the Aprasia genera are opportunistic “binge feeders” which feed infrequently, but when they do come across an ant brood for instance, they will feed in excess. Studies on how Aprasia species can locate ant colonies, and specifically ant broods, have not yet been researched and are open for inquest, with

chemoreceptor A chemoreceptor, also known as chemosensor, is a specialized sensory receptor which transduces a chemical substance (endogenous or induced) to generate a biological signal. This signal may be in the form of an action potential, if the chemorecept ...

s of ant pheromonal trails being a possible explanation which is a similar adaptation of some snake species. Pygopodids are predated upon by diurnal raptors, elapid snakes,

goanna A goanna is any one of several species of lizards of the genus '' Varanus'' found in Australia and Southeast Asia. Around 70 species of ''Varanus'' are known, 25 of which are found in Australia. This varied group of carnivorous reptiles ranges ...

feral cat A feral cat or a stray cat is an unowned domestic cat (''Felis catus'') that lives outdoors and avoids human contact: it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens ...

s and

fox Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or ''brush''). Twelve sp ...

es, of which, they represent a minor dietary component for these

predators Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

. Aprasia inaurita was observed by Rankin (1976) to raise its tail from the substrate and wave it when prodded, suggesting that the tail may be for defence purposes, and being brightly coloured and blunt, it may be used as a decoy for predators. Pygopodids have also been found to be predated upon by the

trematode Trematoda is a class of flatworms known as flukes. They are obligate internal parasites with a complex life cycle requiring at least two hosts. The intermediate host, in which asexual reproduction occurs, is usually a snail. The definitive host ...

''Paradistoma Crucifer'', the

cestode Cestoda is a class of parasitic worms in the flatworm phylum (Platyhelminthes). Most of the species—and the best-known—are those in the subclass Eucestoda; they are ribbon-like worms as adults, known as tapeworms. Their bodies consist of man ...

''Acanthotaenia striata'' and by the

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

s Abbreviata sp.

Taxonomy and Distribution

The Mallee Worm-lizard belongs to the

Pygopodidae Pygopodidae, commonly known as legless lizard, legless lizards, snake-lizards, or flap-footed lizards, is a Family (biology), family of squamates with reduced or absent limbs, and are a type of gecko. At least 35 species are placed in two subfami ...

family of

Squamates Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,900 species, i ...

(scaled reptiles), commonly referred to as ‘

legless lizard Legless lizard may refer to any of several groups of lizards that have independently lost limbs or reduced them to the point of being of no use in locomotion.Pough ''et al.'' 1992. Herpetology: Third Edition. Pearson Prentice Hall:Pearson Education ...

s’ for their snake-like appearance with absent forelimbs and very small vestigial hind-limb flaps which, for the Mallee Worm-lizard, occur as small scaley flaps located by the cloacal vent. The

family are recognised as a being closely related to two families 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 ...

, the

Carphodactylidae The Carphodactylidae, informally known as the southern padless geckos, are a family of geckos, lizards in the infraorder Gekkota. The family consists of 32 described species in 7 genera, all of which are endemic to Australia. They belong to the s ...

and

Diplodactylidae The Diplodactylidae are a family in the suborder Gekkota (geckos), with over 150 species in 25 genera. These geckos occur in Australia, New Zealand, and New Caledonia. Diplodactylids are the most ecologically diverse and widespread family of geck ...

, and are represented by 47 species, of which, 35 species are placed into two subfamilies, the Lialisinae and the Pygopodinae, with 7 genera:

Lialis ''Lialis'' is a genus of legless lizards in the family Pygopodidae. The genus is native to Australia and New Guinea. Diet Lizards in the genus ''Lialis'' specialize in eating skinks.Patchell F, Shine R (1986). "Feeding Mechanisms in Pygopodid L ...

(two species),

Delma ''Delma'' is a genus of lizards in the family Pygopodidae. The genus ''Delma'' contains 22 valid described species, all of which are endemic to Australia. Species Recognized species of ''Delma'' according to thReptile Database *''Delma australi ...

(22 species), Paradelma (monotypic),

Pygopus ''Pygopus'' is a genus belonging to the family of Australian legless lizards (Pygopodidae). Members of this genus are also commonly called scaly-foot. Species Within the genus ''Pygopus'' the following five species are recognized as being valid. ...

(five species), Ophidiocephalus (monotypic),

(15 species), Pletholax (two species). The

genera are noted as one of the most divergent genera from the

family. The Mallee Worm-lizard (''Aprasia inaurita'') is a part of the

genera which are predominately found in

Southern Australia The term Southern Australia is generally considered to refer to the states and territories of Australia of New South Wales, Victoria, Tasmania, the Australian Capital Territory and South Australia. The part of Western Australia south of lati ...

, with the Mallee Worm-lizard itself being distributed across a narrow band which stretches from the southeast of

, across southern

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 ...

, the northwest corner of

and southwestern

. The

IBRA The Interim Biogeographic Regionalisation for Australia (IBRA) is a biogeographic regionalisation of Australia developed by the Australian government's Department of Sustainability, Environment, Water, Population, and Communities. It was devel ...

(Interim Biogeographic Regionalisation for Australia) regions that the Mallee Worm-lizard occurs in NSW are the

Murray Darling Depression The Murray Darling Depression , also known as the Murray-Darling woodlands and mallee, is a 19,717,651 HA biogeographic region and an ecoregion in southeastern Australia consisting of a wooded plain through which flow two of Australia's biggest ri ...

and

Riverina The Riverina is an agricultural region of south-western New South Wales, Australia. The Riverina is distinguished from other Australian regions by the combination of flat plains, warm to hot climate and an ample supply of water for irrigation ...

regions, with 8% occurrence across New South Wales’ reserves. More specifically, the Mallee Worm-lizard has been discovered through the Mallee region between

Balranald Balranald is a town within the local government area of Balranald Shire, in the Riverina district of New South Wales, Australia. The town of Balranald is located where the Sturt Highway crosses the Murrumbidgee River in a remote, semi-desert ...

and Gol Gol with centralised recordings of the Mallee Word-lizard in the Mallee Cliffs National Park area. Recordings of the Mallee Worm-lizard have also been found in the central mallee region around

Pulletop Pulletop is a rural locality in the south eastern part of the Riverina The Riverina is an agricultural region of south-western New South Wales, Australia. The Riverina is distinguished from other Australian regions by the combination of f ...

and Gubbata Nature Reserves and around the Scotia mallee area. Due to the severely fragmented distribution of this species, local populations of the Mallee Worm-lizard are vulnerable to

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

from stochastic events.

Reproduction

Pygopodids are noted as being

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

(egg laying) and will have a usual clutch size of two with an incubation period of 66 to 77 days, which is common for the Mallee Worm-lizard which will mate in Spring and lay in October. A study on the sex of Aprasia inaurita determined that adult males of the species contained the presence of 'spurs' on their hindlimb flaps which were found to not be present in the adult females or juveniles of the

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

. The males of all Aprasia genera also had toothed

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

, as opposed to juveniles and females with none, or being

vestigial Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on co ...

in females. This dimorphism has been inferred to either assist males in bouts with other males, to hold down females during

copulation Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetrat ...

, or to assist males in taking down larger prey. Pygopodids have lived up to 7 years in captivity, however, little else is known of the life history of Pygopodids, in particular, the Mallee Worm-lizard.

Threats

A major threat on the Mallee Worm-lizard is

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

through clearing, as well as

agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...

and land management practices, which thereby remove debris and ground cover that the Mallee Worm-lizard depends upon. With mallee vegetation once covering 383,000 km², 35% of this has since been removed through

land clearing Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...

. Agricultural practices can also increase

soil compaction In geotechnical engineering, soil compaction is the process in which stress applied to a soil causes densification as air is displaced from the pores between the soil grains. When stress is applied that causes densification due to water (or other ...

through machinery and livestock, from which, livestock can feed upon and also trample on important food resources. The Mallee Worm-lizard is also under threat by introduced pest species, i.e., the introduced European rabbit (

Oryctolagus cuniculus The European rabbit (''Oryctolagus cuniculus'') or coney is a species of rabbit native to the Iberian Peninsula (including Spain, Portugal, and southwestern France), western France, and the northern Atlas Mountains in northwest Africa. It has b ...

), the red fox (''

Vulpes Vulpes The red fox (''Vulpes vulpes'') is the largest of the true foxes and one of the most widely distributed members of the order Carnivora, being present across the entire Northern Hemisphere including most of North America, Europe and Asia, plus ...

'') and the house cat (''

Felis catus The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of t ...

''). Altered

fire regime A fire regime is the pattern, frequency, and intensity of the bushfires and wildfires that prevail in an area over long periods of time. It is an integral part of fire ecology, and renewal for certain types of ecosystems. A fire regime describes th ...

s may also pose a threat to the Mallee Worm-lizard through the reduced availability of Spinifex habitat which would thereby increase the chances of predators to find and prey upon the Mallee Worm-lizard. Although the immediate effects of fire on the Mallee Worm-lizard found no observed effect on this species after a fire event It is however affected by impacts upon its habitat.

Status

The Mallee Worm-lizard is described as being of

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(International Union for Conservation of Nature) red list, however, in 2004 the Mallee Word-lizard (''Aprasia inaurita'') is listed as an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inv ...

within the Australian state of

. The New South Wales scientific committee confirming that if the circumstances and factors that threaten the survival of the Mallee Worm-lizard do not cease than the Mallee Worm-lizard is likely to become extinct in nature within New South Wales. Due to this status within New South Wales, the Mallee Worm-lizard has been assigned to the landscape management stream according to the New South Wales Saving our Species (SoS) program which focuses on the threats of habitat destruction and the impacts of landscape clearing, with the aim of securing the Mallee Worm-lizards in the wild in New South Wales and extending, or maintaining, its New South Wales’ geographical range.Office of Environment and Heritage (OEH). n.d. Mallee Worm-lizard (''Aprasia inaurita'') – Saving our Species strategy. Department of Planning Industry and Environment. https://www.environment.nsw.gov.au/savingourspeciesapp/project.aspx?ProfileID=10060

References

{{Taxonbar, from=Q6452066 Aprasia Pygopodids of Australia Endemic fauna of Australia Reptiles described in 1974 Taxa named by Arnold G. Kluge