Sydney Funnel-Web Spider
Atrax robustus
Atracidae (Funnel-web Spiders), Order Araneae
Physical Description
Robust, heavy-bodied spider with a glossy, dark-brown to black carapace. The abdomen is dark, plump, and covered in fine hairs. It features large, powerful, downward-pointing chelicerae (fangs) capable of piercing human skin easily.
Size Estimate
Body length typically ranges from 1 to 5 cm (0.4 to 2 inches) with a leg span of up to 6 to 7 cm.
Coloration & Markings
Uniformly glossy black, bluish-black, or dark brown carapace with a smooth, hairless caput (head region). The abdomen is dark plumbeous to black, lacking prominent patterns.
Web Type
Constructs a characteristic silk-lined burrow or tubular retreat shaped like a funnel, often with sticky trip-lines radiating from the entrance.
Eye Arrangement
Small eyes grouped closely together on a distinct elevated tubercle near the front of the carapace.
Leg Characteristics
Thick, strong legs covered in fine hairs and prominent spines. The legs are sturdy and adapted for digging and robust movement, often held in a defensive, raised posture when threatened.
Venom & Safety Information
Venom Information
Contains robustoxin, a powerful neurotoxin that is notoriously toxic to humans and other primates, though harmless to dogs and cats.
Medical Significance
Medically significant and potentially lethal. A bite causes severe envenomation symptoms including muscle spasms, profuse sweating, salivation, and dangerous blood pressure changes. Antivenom developed in 1981 has successfully prevented fatalities since its introduction.
Safety Recommendations
Wear gloves when gardening in endemic areas, keep footwear indoors, and never handle a funnel-web. If bitten, apply pressure immobilization bandaging and seek emergency medical attention immediately.
Habitat & Behavior
Habitat & Range
Found exclusively in eastern Australia, primarily within a 160 km radius of Sydney, inhabiting moist, sheltered microhabitats such as rotting logs, under bark, and in deep garden soil.
Behavior & Temperament
Highly aggressive and defensive when provoked. When cornered, it rears up onto its hind legs, displays its large fangs, and drips venom from the tips before striking.
Diet & Prey
Predominantly feeds on large ground-dwelling insects, beetles, cockroaches, slaters, and occasionally small vertebrates like frogs and lizards.
Seasonal Activity
Most active during the warmer, humid months of austral summer, particularly after heavy rain when males wander extensively in search of females.
Description
The Sydney Funnel-Web Spider is one of the most famous and feared spiders in the world. With its glossy dark armor, intimidating size, and potent neurotoxic venom, it commands respect. Despite its dangerous reputation, it plays an important ecological role as an apex predator of the forest floor.
Key Features
Glossy black carapace, massive downward-pointing fangs, tightly grouped eyes on a tubercle, and a robust body build associated with moist funnel-web burrows.
Similar Species
Mouse spiders (Missulena spp.) and Hadronyche spp. (other funnel-webs). Mouse spiders can look very similar but often have lighter-colored jaws or head regions.
Life Cycle
Females lay up to 100 or more eggs inside a silk egg sac kept within the burrow. Spiderlings hatch and disperse after the first few molts. Males wander in search of mates during warmer months. Lifespan ranges from 4 to 8 years.
Ecological Importance
Acts as an essential apex predator in its native bushland and garden ecosystems, helping to regulate insect populations and participating in local food webs.
Conservation Status
Not threatened globally; common within its restricted geographic range, though urban expansion frequently brings them into contact with humans.
Interesting Facts
Unlike most other venomous spiders, Sydney funnel-web venom is remarkably potent to humans and primates while having almost no toxic effect on cats, dogs, and other common household pets.
Photography Tips
Photograph from a safe distance using a macro lens with a high shutter speed. Avoid provoking the spider to strike or rear up during the session.
Identified: 2026-09-11T00:15:55.141001