Pygmy Copperhead

The pygmy copperhead (Austrelaps labialis) is an Australian venomous elapid snake species found on Kangaroo Island Fleurieu Peninsula and the Mount Lofty Ranges where it is considered under threat. It is the only snake endemic to South Australia. It is from the Austrelaps genus along with two other species of copperhead, the Highland and Lowland copperhead snakes.

Adult pygmy copperhead snakes grow to an average of 80 cm (31 in) 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 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 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 (Viperidae).

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 80 cm (31.5 in) in length, with larger specimens reaching 120 cm (47.2 in) 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 scales and 35–55 subcaudal scales, with an average of 15 rows of scales along their mid-bodies, and a single anal scale.