| Atrax yorkmainorum | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Class: | Arachnida |
| Order: | Araneae |
| Infraorder: | Mygalomorphae |
| Family: | Atracidae |
| Genus: | Atrax |
| Species: | A. yorkmainorum
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| Binomial name | |
| Atrax yorkmainorum | |
Atrax yorkmainorum is a venomous species of Australian funnel-web spider belonging to the Atracidae family and is found in forests in the vicinity of Canberra and south-eastern New South Wales. The genus Atrax was first documented in 1877 and the Atrax yorkmainorum species was first described in 2010.
The adult male and female have a similar appearance, with the female being slightly larger. Females generally have a body length of 18.84mm whilst the male has an average body length between 16-17mm. Both sexes have a matte abdomen with a dark brown/black shiny body.
Funnel web spiders are mainly nocturnal and perform their hunting, web-making and mating at night. The female Atrax yorkmainorum spends most of its time within its distinguishable burrow that is lined with silk trip lines that extrude out from the tunnel. It preys on small and large insects as well as lizards that walk across the silk trip lines. The spider will sense the vibrations from the web, then attack its prey by injecting venom with its fangs to immobilise and break down its victim. During mating, the second leg of the female spider is locked in a raised position by the characteristic dorsal spine on the males second pair of legs. Once locked in the raised position, the male releases his sperm into the females spermathecae where it is then stored until the female allows fertilisation of the eggs. Male spiderlings mature within 3–4 years of being in the burrow while the final moult for females occurs 1–2 years after the male.
Atrax yorkmainorum does not have a widespread distribution within Australia, remaining within the forest areas of south-eastern New South Wales, as well as the Australian Capital Territory. Most sightings occur during the humid, wet months where male activity is at its highest. Funnel web spiders belonging to the Atrax genus are highly venomous spiders and chance of death without anti-venom is high. The venom of the male spider is significantly more toxic than the female spider's venom. The spiders venom contains neurotoxic toxins such as δ-atracotoxin, that interfere with voltage gated sodium channel activation, which is responsible for the paralyses effect of Atrax bites.
Some of the systemic symptoms of Atrax yorkmainorum envenomation include mouth spasms, tongue and muscle fasciculation, nausea, hypersalivation, increased sweating and pulmonary edema. Pressure immobilisation bandaging (PIB) is used to delay envenoming until an anti-venom is accessible. An anti-venom for Atrax spider bites has been available since the late 1980s and has saved many lives from funnel web spider envenomation.