Sydney Funnel-Web Spider
Atrax robustus
Hexathelidae (Australian Funnel-Web Spiders), Order Araneae. Key family characteristics include deep gutter-like furrows on the carapace and spinnerets that are noticeably elongated.
Physical Description
Robust, heavily built body with a glossy, dark blue-black to plum-black carapace. The abdomen is velvety, deep brown to black, and densely covered in fine hairs. The chelicerae (fangs) are large, powerful, and project forward.
Size Estimate
Body length ranges from 1 to 5 cm (0.4 to 2 inches) with a leg span of up to 6 to 7 cm. This specimen appears to be an adult.
Coloration & Markings
Uniformly dark glossy black or dark plum cephalothorax with very little patterning. The abdomen is matte black or dark brown. Males often have a distinct spur on the second pair of legs.
Web Type
Tube-like silk retreat web with trip-lines radiating outwards from the entrance. Usually built in damp, sheltered areas under logs, rocks, or in crevices.
Eye Arrangement
Eight small eyes closely grouped together on a small tubercle at the front center of the carapace, typical of mygalomorph spiders.
Leg Characteristics
Strong, thick legs with dense hairs and powerful spines. The tarsi bear three claws. In defensive posture, the front legs are raised high and fangs are exposed.
Venom & Safety Information
Venom Information
Contains robustoxin (atracotoxin), a potent neurotoxin that specifically targets the human nervous system by affecting voltage-gated sodium channels.
Medical Significance
Extremely dangerous and potentially fatal to humans, particularly bites from mature males. Symptoms include profuse sweating, muscle spasms, hypertension, and respiratory distress. Antivenom developed in 1981 has successfully prevented deaths since its introduction.
Safety Recommendations
Wear gloves when gardening in endemic areas, keep shoes indoors, shake out footwear before wearing, and never handle a funnel-web. Seek immediate medical emergency care and apply pressure immobilization bandage if bitten.
Habitat & Behavior
Habitat & Range
Endemic to the east coast of Australia, specifically within a 100-mile radius of Sydney, New South Wales. Prefers moist, sheltered microhabitats such as gardens, forests, and damp crevices.
Behavior & Temperament
Aggressive and defensive when disturbed. They adopt a threat display, rearing up and displaying venom-dripping fangs before striking rapidly downward.
Diet & Prey
Insects, large beetles, cockroaches, slaters, and occasionally small vertebrates like frogs or lizards that wander across the web trip-lines.
Seasonal Activity
Most active during the warmer, humid summer and autumn months, particularly after heavy rainfall when males actively roam for mates.
Description
The Sydney Funnel-Web Spider is one of the world's most infamous arachnids, renowned for its potent venom and aggressive posture. With its glossy black carapace and powerful, downward-pointing fangs, it is a formidable hunter of the Australian undergrowth.
Key Features
Glossy, dark carapace; large forward-facing fangs; elongated spinnerets; characteristic burrow with silk trip-lines; and highly defensive threat posture.
Similar Species
Mouse spiders (Missulena spp.), which have bulkier heads and bright red or blue jaws, and garden wolf spiders, which are faster and lack the glossy carapace.
Life Cycle
Females lay eggs inside a silk egg sac hidden within the burrow. Spiderlings hatch and disperse after a few molts. Females can live for several years, while males die shortly after reaching maturity and seeking mates.
Ecological Importance
Acts as an apex invertebrate predator in its native forest ecosystem, helping control populations of large ground-dwelling insects and maintaining ecological balance.
Conservation Status
Not threatened; common within its restricted geographic range and highly adaptable to suburban gardens.
Interesting Facts
Unlike most spiders, male Sydney funnel-webs wander from their burrows during mating season in search of females, frequently ending up in swimming pools or suburban homes.
Photography Tips
Photograph from a safe distance using a macro lens. Avoid provoking the spider to prevent defensive strikes. Natural, diffused outdoor lighting works best to capture the glossy texture of the carapace.
Identified: 2026-09-18T05:42:26.927814