Atracidae
These spiders are burrow dwellers that use silk trip-lines radiating from their burrow entrance to detect approaching prey. They are likely ambush predators that emerge from their burrows to capture unsuspecting invertebrates.
Atracidae, commonly known as Australian funnel-web spiders, are a family of mygalomorph spiders native to Australia. These spiders are medium to large in size and are distinguished by their powerful fangs and the males' mating spurs. Some species possess venom that is dangerous to humans, with the Sydney funnel-web spider and northern tree-dwelling funnel-web spider being particularly noted for their potentially deadly bites.
Key Facts
- ›Native to Australia, with species found in New South Wales, South Australia, Victoria, Tasmania, and Queensland.
- ›Body lengths range from 1 to 5 CM, with some specimens reaching up to 8 CM.
- ›Possess powerful fangs capable of penetrating tough materials like fingernails and soft shoes.
- ›Males have a prominent mating spur on their second pair of legs.
- ›Venom from certain species is highly toxic to primates, including humans, but less so to other animals.
- ›Bites from six species have caused severe injuries, with the Sydney funnel-web spider (Atrax robustus) and northern tree-dwelling funnel-web spider (Hadronyche formidabilis) being the most dangerous.
Australian Funnel-Web Spiders, Atracids
Australia
- Hairless Carapace Covering the Front Part of Their Bodies.
- Males Have A Large Mating Spur Projecting From the Middle of Their Second Pair of Legs.
- Fangs Point Straight Down the Body, Not Towards Each Other.
- Large and Powerful Fangs Capable of Penetrating Fingernails and Soft Shoes.
- Burrows Have Irregular Silk Trip-Lines Radiating From the Entrance.
- Males Wander During Warmer Months In Search of Mates.
- Attracted To Water, Often Found In Swimming Pools.
- Can Survive Immersion In Water For Several Hours.
- Cannot Jump But Can Run Quickly.
About Atracidae
Atracidae: Australian Funnel-web Spiders
Atracidae, commonly known as Australian funnel-web spiders, represent a significant family of mygalomorph spiders native to Australia. These spiders are characterized by their medium to large size, with body lengths typically ranging from 1 to 5 cm, though some individuals can reach up to 8 cm. They possess a distinctive hairless carapace and strong, powerful fangs that can penetrate tough materials like fingernails and soft shoes.
Distribution and Habitat
The geographical range of Australian funnel-web spiders is primarily the eastern coast of Australia, including New South Wales, South Australia, Victoria, Tasmania, and Queensland. They favor moist, cool, and sheltered environments, often making their burrows under rocks, within rotting logs, or in the rough bark of trees. These spiders are frequently encountered in suburban rockeries and shrubberies, with their burrows typically marked by irregular silk trip-lines radiating from the entrance.
Medical Significance
Members of the Atracidae family are among the most medically significant spiders globally, with some species possessing venom dangerous to humans. Six species have been documented as causing severe injuries, with the Sydney funnel-web spider (Atrax robustus) and the northern tree-dwelling funnel-web spider (Hadronyche formidabilis) being particularly noted for their potentially deadly bites. Wandering males are often implicated in bites, as they search for mates during warmer months and can be found in areas like swimming pools. While their bites can be severe, fatalities have been significantly reduced with the advent of modern first-aid techniques and antivenom.
Venom and Symptoms
The venom of Atracidae spiders contains toxins known as atracotoxins (ACTX). These toxins can cause rapid and severe systemic envenomation in primates, leading to symptoms such as intense pain, sweating, tingling, salivation, increased heart rate and blood pressure, and potentially progressing to nausea, vomiting, breathing difficulties, muscle spasms, and in severe cases, death. While potent to humans, the venom is often less harmful to other animals due to specific neutralizing factors in their blood plasma. The venom of male spiders is generally considered more potent than that of females.
Treatment and Research
Prompt first-aid, including the application of a pressure immobilization bandage and splinting, is crucial for suspected bites. The development of a highly effective antivenom in 1981 has dramatically reduced the mortality rate associated with these bites, with most patients recovering within a few days. Research into funnel-web spider venom has also revealed potential therapeutic applications, such as the discovery of a molecule that could protect the heart after injury.
Source: Wikipedia ↗
Frequently Asked Questions
What are Australian funnel-web spiders?
Australian funnel-web spiders, belonging to the family Atracidae, are a group of mygalomorph spiders found exclusively in Australia. They are known for their potent venom and distinctive burrowing habits.
Where are Atracidae spiders found?
These spiders are primarily found along the eastern coast of Australia. Their distribution includes New South Wales, South Australia, Victoria, Tasmania, and Queensland. Western Australia and the Northern Territory are the only Australian states or territories without members of this family.
Are all Australian funnel-web spiders dangerous to humans?
While some species produce venom that is dangerous to humans, not all bites are equally severe. Bites from six specific species have caused severe injuries, with the Sydney funnel-web spider and the northern tree-dwelling funnel-web spider being considered potentially deadly.
What are the symptoms of an Australian funnel-web spider bite?
Symptoms typically manifest rapidly and include intense pain at the bite site, sweating, tingling around the mouth, salivation, elevated heart rate, and blood pressure. As envenomation progresses, more severe symptoms like nausea, vomiting, difficulty breathing, and muscle spasms can occur.
How are Australian funnel-web spider bites treated?
Immediate first-aid involves applying a pressure immobilization bandage to the bitten limb and immobilizing it with a splint. The primary medical treatment is antivenom, which has been highly effective in preventing fatalities since its development.
Do male or female funnel-web spiders pose a greater risk?
Wandering males are implicated in most, if not all, fatal Australian funnel-web spider bites to humans. They tend to wander during mating season and are attracted to water, sometimes falling into swimming pools.
Related Spider species
Theridiidae
Theridiidae, commonly known as tangle-web spiders or cobweb spiders, is a large and diverse family of araneomorph spiders found globally. They are notable for being the most common arthropod group in human dwellings worldwide and for spinning sticky capture silk, a characteristic that distinguishes them within the spider order.
Sicariidae
Sicariidae is a family of six-eyed venomous spiders, encompassing approximately 180 species across three genera. They are distinguished by their unique sphingomyelinase D venom, which can cause necrotic lesions, and members like the brown recluse and six-eyed sand spider are well-known. These spiders are found in warmer regions worldwide and deserts of southern Africa and the Americas, often exhibiting self-burying behaviors.
Actinopodidae
Actinopodidae is a family of mygalomorph spiders native to mainland Australia and South America, typically inhabiting open forests. This family includes the mouse spiders (Missulena species), which are notable for their medically significant and potentially dangerous bites.