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 ; grc, ἔλλοψ ''éllops'' "sea-fish") is a 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 Emydoceph ...

snake

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 ...

found on

Kangaroo Island Kangaroo Island, also known as Karta Pintingga (literally 'Island of the Dead' in the language of the Kaurna people), is Australia's third-largest island, after Tasmania and Melville Island. It lies in the state of South Australia, southwest ...

and the

Fleurieu Peninsula The Fleurieu Peninsula () is a peninsula in the Australian state of South Australia located south of the state capital of Adelaide. History Before British colonisation of South Australia, the western side of the peninsula was occupied by the K ...

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 copperhe ...

'' 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 speaking, upland (or uplands) refers to ranges of hills, typically from up to while highland (or highlands) is ...

and

Lowland copperhead The lowland copperhead or lowlands copperhead (''Austrelaps superbus'') is a venomous snake species in the family Elapidae, found in southeastern Australia and Tasmania. It is commonly referred to as the copperhead, but is not closely related to ...

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 ''Tantilla'' is a large genus of harmless New World snakes in the family Colubridae. The genus includes 66 species, which are commonly known as centipede snakes, blackhead snakes, and flathead snakes.Wilson, Larry David. 1982. Tantilla. ...

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. Since 1976, he has written books and articles about official corruption in Australia. He has also written works on Australian frogs and reptiles. Hoser's work on herp ...

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 as the copperhead, is a species of venomous snake, a pit viper, endemic to eastern North America; it is a member of the subfamily Crotalinae in the family Viperidae. The eastern ...

'' (

Viperidae The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs tha ...

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 unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...

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 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 ...

and restricted to a small section of

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 ...

(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 ...

. 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 leaf, leaves, short Internode (botany), internodes (the distance between leaves along the stem) and leaf orientation which is paral ...

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, as well as on islands between the Australian mainland and

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

, 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. Flinders Island was the place where the last remnants of aboriginal Tasmanian population were exiled by the colon ...

, Hunter Island,

King Island King Island, Kings Island or King's Island may refer to: Australia * King Island (Queensland) * King Island, at Wellington Point, Queensland * King Island (Tasmania) ** King Island Council, the local government area that contains the Tasmanian is ...

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

and

Great Dog Island Great Dog Island is an uninhabited islet of the British Virgin Islands in the Caribbean. It is located in a smaller sub-group of islands referred to as the Dog Islands, or more commonly, "The Dogs". Other islets in The Dogs include Little Se ...

, 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 (from the Greek () "outside" and () "heat") is an organism in which internal physiological sources of heat are of relatively small or of quite negligible importance in controlling body temperature.Davenport, John. Animal Life a ...

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 permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to the transmission of nervous impulses from ...

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 – specificall ...

, with toxicity similar to that of the

Indian cobra The Indian cobra (''Naja naja''), also known as the spectacled cobra, Asian cobra, or binocellate cobra, is a species of cobra found in India, Pakistan, Bangladesh, Sri Lanka, Nepal, and Bhutan, and a member of the "big four" species that are ...

. 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 Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the m ...

, 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