The pygmy copperhead (''Austrelaps labialis'') is an Australian

venomous Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

elapid Elapidae (, commonly known as elapids , from , variant of "sea-fish") is a family (biology), family of snakes characterized by their permanently erect fangs at the front of the mouth. Most elapids are venomous, with the exception of the genus ...

snake

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

found on

Kangaroo Island Kangaroo Island (, ) is Australia's third-largest island, after Tasmania and Melville Island, Northern Territory, Melville Island. It lies in the state of South Australia, southwest of Adelaide. Its closest point to the mainland is Snapper Poi ...

and the

Fleurieu Peninsula The Fleurieu Peninsula ( ; locally mainly ) is a peninsula in the Australian state of South Australia located south of the state capital of Adelaide city centre, Adelaide. History Before British colonisation of South Australia, the western s ...

in South Australia. It is from the ''

Austrelaps ''Austrelaps'' is a genus of venomous elapid snakes native to the relatively fertile, temperate, southern and eastern part of the Australian continent. Three species are currently recognized, with no subspecies. They are commonly called copperhea ...

'' genus along with two other species of copperhead, the

Highland Highlands or uplands are areas of high elevation such as a mountainous region, elevated mountainous plateau or high hills. Generally, ''upland'' refers to a range of hills, typically from up to , while ''highland'' is usually reserved for range ...

and Lowland copperhead snakes. Adult pygmy copperhead snakes grow to an average of making it the smallest of Australian copperheads. It preys on small reptiles and frogs. Their bite is considered possibly lethal but they are unlikely to attack unless stepped on or purposely provoked. They are not considered to be in need of conservation.

Taxonomy

The pygmy copperhead was first described as the ''Alecto Labialis'' by

Giorgio Jan Giorgio Jan (21 December 1791 in Vienna – 8 May 1866, Milan) was an Italian taxonomist, zoologist, botanist, herpetologist, and writer. He is also known as Georg Jan or Georges Jan. He was the first director of the natural history museum at Mi ...

in 1859. This name was also briefly given to the White-lipped Snake in 1873 by Jan and associate Ferdinando Sordelli. It was formerly included in '' Austrelaps superbus'' which, at the time, also included the highland and lowland copperhead snakes under the same name''.'' The three species were officially separated in 1991 in a publication from P. A. Rawlinson, detailing key differences in appearance, distribution and behaviour between each type. This publication renames the pygmy copperhead to ''Austrelaps labialis'', with ''Austrelaps superbus'' remaining the name for the highland copperhead. Snake-catcher

Raymond Hoser Raymond Terrence Hoser (born 1962) is an Australian snake-catcher and author. Hoser's work on herpetology is controversial, including his advocacy of the surgical alteration of captive snakes to remove their venom glands and his self-published ...

has disputed the separation of species in ''Austrelaps'', claiming the main separation is related only to environmentally influenced changes. His paper has however been challenged by the wider community. The common naming of the snake refers to the colouration of the scales on top of its body and those surrounding the snake’s snout and eyes, and "pygmy" refers to the species being smaller than the highland and lowland counterparts. Other common names include the pigmy copperhead, dwarf copperhead, Adelaide Hills copperhead and Jan’s copperhead. It is not closely related to the American copperhead, ''

Agkistrodon contortrix The eastern copperhead (''Agkistrodon contortrix''), also known simply as the copperhead, is a widespread species of venomous snake, a pit viper, endemic to eastern North America; it is a member of the subfamily Crotalinae in the Family (biology ...

'' (

Viperidae Vipers are snakes in the family Viperidae, found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, New Zealand, Ireland, and various other isolated islands. They are venomous snake, venomous and have long (relat ...

Description

The pygmy copperhead is the smallest of Australian copperhead snakes. It is expected for the males to grow to a larger size than the females, but the pygmy copperhead's ratio is more marked than most other snake species. On average, the adult male snake reaches in length, with larger specimens reaching long. The total length the snake can reach has been debated, with previous publications and research only finding specimens of 60 cm, 70 cm and 85 cm. On both sexes, the dorsal scales come in shades of brown to grey, with a notable darker stripe along the spine. The abdominal area is cream to light-grey in colouration, with varying intensities of red along the edges before transitioning to the brown-grey backside. The labial scales of the pygmy copperhead are barred with dark colouration. There can be from 140 to 165

ventral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

scales and 35–55 subcaudal scales, with an average of 15 rows of scales along their mid-bodies, and a single anal scale. Newborns often have paler backsides in comparison to adult pygmy copperheads. Image:Austrelaps labialis head.JPG, ''Austrelaps labialis'' head

Distribution and habitat

The pygmy copperhead is

endemic Endemism is the state of a species being found only 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 foun ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and restricted to a small section of

South Australia South Australia (commonly abbreviated as SA) is a States and territories of Australia, state in the southern central part of Australia. With a total land area of , it is the fourth-largest of Australia's states and territories by area, which in ...

(state), particularly

and immediately adjacent mainland within the

and the

Mount Lofty Ranges The Mount Lofty Ranges are a range of mountains in the Australian state of South Australia which for a small part of its length borders the east of Adelaide. The part of the range in the vicinity of Adelaide is called the Adelaide Hills and d ...

. The limited area is characteristically moist, with an average yearly rainfall of and milder summer temperatures, . They are found living in concentrated numbers near streams, in swamps, marshland and open

sclerophyll Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short Internode (botany), internodes (the distance between leaves along the stem) and leaf orientation which is parallel or ...

woodlands and forests. The cold temperatures in these areas are notably too low for many other reptilian species. There have been sightings of individual pygmy copperheads in the

Adelaide Hills The Adelaide Hills region is located in the southern Mount Lofty Ranges east of the city of Adelaide in the state of South Australia. The largest town in the area, Mount Barker, South Australia, Mount Barker, is one of Australia's fastest-growi ...

, as well as on islands between the Australian mainland and

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

, including

Flinders Island Flinders Island, the largest island in the Furneaux Group, is a island in the Bass Strait, northeast of the island of Tasmania. Today Flinders Island is part of the state of Tasmania, Australia. It is from Cape Portland, Tasmania, Cape Portl ...

, Hunter Island,

, King Island,

Preservation Island Preservation Island is a low and undulating granite and calcarenite island, with an area of 207 hectare, ha, in south-eastern Australia. It is part of Tasmania’s Preservation Island Group, lying in eastern Bass Strait south-west of Cape Barren ...

and Great Dog Island, probably from having accidentally stowed away on boats.

Behaviour and relationship with humans

The pygmy copperhead is a common species but rarely seen. It is generally unobtrusive, commonly hiding under leaf litter, old iron and haystacks. The lowland and highland species can be potentially dangerous, but being smaller, the pygmy is not known for being aggressive. They are all considered non-threatening unless provoked. Combat between males signifies sexual maturity in snakes, but it has not been observed in pygmy copperheads, despite the lowland and highland species exhibiting at two years of age.

Feeding

Being carnivorous, the pygmy copperhead's diet consists of smaller

ectotherm An ectotherm (), more commonly referred to as a "cold-blooded animal", is an animal in which internal physiological sources of heat, such as blood, are of relatively small or of quite negligible importance in controlling body temperature.Dav ...

s, most commonly including small lizards, frogs and tadpoles. They are known to feed more frequently than highland and lowland copperheads. There have also been reports of cannibalism in the pygmy copperheads.

Venom

Bites are considered lethal without prompt anti-venom intervention, with possible irreversible

presynaptic In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending o ...

damage. The pygmy copperhead’s venom is classed as strongly

neurotoxic Neurotoxicity is a form of toxicity in which a biological, chemical, or physical agent produces an adverse effect on the structure or function of the central and/or peripheral nervous system. It occurs when exposure to a substance – specifical ...

, with toxicity similar to that of the

Indian cobra The Indian cobra (''Naja naja /na''dʒa nadʒa/), also known Common name, commonly as the spectacled cobra, Asian cobra, or binocellate cobra, is a species of Naja, cobra, a venomous snake in the Family (biology), family Elapidae. The species is ...

. It is weakly coagulant and strongly anticoagulant, with the ability to be both blood and muscle destroying. Antivenom developed through the tiger snake is unable to completely neutralise the neurotoxicity of the whole venom, nor a modified version in research lab trials.

Reproduction

The pygmy copperhead is

viviparous In animals, viviparity is development of the embryo inside the body of the mother, with the maternal circulation providing for the metabolic needs of the embryo's development, until the mother gives birth to a fully or partially developed juve ...

, commonly giving live birth to seven young in each litter, with an average maximum of 20 young in a single litter. The litter size is half that of the other Australian copperheads, attributed to their smaller body size and the maternal snout-vent length ( SVL) and litter size ratio. There also appears to be a skewed sex ratio towards males. Female ovulation in the pygmy copperhead is in spring, but field research found that only two thirds of surveyed (apparently adult) females were reproductive, suggesting that females do not reproduce every year.

References

External links

* {{Taxonbar, from=Q2384650 Austrelaps Snakes of Australia Reptiles of South Australia Endemic fauna of Australia Vulnerable fauna of Australia Reptiles described in 1859 Taxa named by Giorgio Jan