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AUSTRALIAN FUNNEL WEB SPIDERS
Family: Hexathelidae. Species: Atrax & Hadronyche
There have been 36 species of Atrax and Hadronyche spiders recorded. Most of these species are regarded as potentially deadly, however bites from species other than Atrax robustus, (Sydney Funnel Web) are extremely rare. Many species have never recorded bites, rarely encountering people. Funnel web spiders are generally found on the east coast of Australia, and are regarded as relics of a line of ancient rainforest spiders. Consequently their distribution is limited by the Great Dividing Range. Several species such as the Blue Mountains Funnel web ( Hadronyche versutus), and the Northern Tree Funnel web (Hadronyche formidablis) are very similar in appearance to the relatively common Sydney Funnel Web. Funnel webs have large forward/downward facing fangs and strong jaws and most raise their 4 front legs as a prelude to a bite. Most build silk lined funnels, tunnels or retreats in the soil, under logs, rocks or in crevices and amongst bark and detritus near trees. Most are nocturnal hunters and all species generally avoid humans. Their food consists of insects and other terrestrial arthropods. Small lizards and frogs and other small vertebrates are occasionally caught.
SYDNEY FUNNEL WEB SPIDER
Sp. Atrax robustus
A large ground dwelling nocturnal spider, the Sydney Funnel Web is the most commonly encountered of all the species. The adult female can measure up to 45mm (body only) and the slightly smaller male attains up to 30mm at maturity. Its range extends beyond the Sydney basin, from Nowra in the South to Newcastle in the North, west to the Blue Mountains. This species has been responsible for an estimated 15 deaths from a recorded number of 380 bites, thus making Atrax robustus statistically the worldıs deadliest spider. The male spider is thought to be responsible for all the fatalities; its venom is up to 5 times more toxic than the females. Sydney Funnel Webs prefer moist dark, sheltered habitats. The adult female lives in a silk lined sac or tube extending back to the brood chamber. At the mouth of the funnel is a wide sheet or mat of silk with long trip lines extending out from the spiders home. These trip lines alert the spider to any potential prey blundering near. The fangs of the Funnel Web are large (2-3mm) downward facing venom delivery apparatus. The spider uses large powerful jaws (called chelicerae) to crush and drive the fangs into its prey. Both the female and the male spider, when disturbed or threatened, will display their powerful fangs by standing on their 4 hind legs. This is a defensive posture and given that these spiders do not jump, the accurate interpretation is that they are (rightly) frightened of being eaten, cannot retreat or turn around and so must prepare to defend themselves. Mating is hazardous and males generally die after mating. Often they are killed or damaged during mating. Due to the fact that the 5-year-old mature male must seek out a female in her retreat, it is he who is more commonly encountered throughout the year. The roaming males often end up in backyard swimming pools and drown. Female spiders generally stay in the same spot and can live for up to 12 years. Up to 100 pale green eggs are laid in a guarded chamber in the retreat. The mother tolerates the spiderlings for a time but eventually disperse to set up their own funnels, usually nearby. The Australian Reptile Park at Somersby, near Gosford, collects donated live spiders to provide venom milked from mature male Sydney Funnel Webs to the Commonwealth Serum Laboratories for production of an anti venene. Since the development of the anti venene in1973 no deaths from funnel web spider bite have been recorded.
 First Aid-
Treat all bites from funnel webs and similar large ground spiders as potentially life threatening. Application of a compression bandage is recommended, immobilization and immediate transport to hospital. Whilst there is anti venene available, the effects of the bite are fast acting. Seek expert medical advice.
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