My Science School

There are about 40,000 species of spiders and nearly all of them have poison glands. Fortunately, in most cases the venom is very weak and has little or no effect on man. The bite of the tarantula was once thought to cause a disease called tarantism when the victim wept and danced wildly. Now it is known that the bite is not dangerous to man.

A few spiders, however, can injure people. One of these is the black widow which lives in North America. Its bite can cause intense pain, severe illness and even death, though this is rare.

In actual fact the mouth of a spider is made in such a way that it cannot really bite. These animals use their venom as a chemical to paralyze their victim. Scientists have found that the venom of spiders in some species breaks down the tissues of the victim and turns them into a sort of jelly which the spider then sucks up because it has no means of chewing its food.

If a spider is not hungry it does not kill its victim immediately. Instead, it imprisons it by wrapping a thick web of threads round it, waiting for the right moment to inject its venom.

 

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Victorian funnel-web, trap-door spiders and mouse spiders do Victorians mistake for a Sydney funnel-web. The Melbourne trap-door spider, stanwellia grisea, looks similar to the Sydney funnel-web. It is found throughout the Melbourne metropolitan area. The Melbourne trap-door spider is quite aggressive, but rarely bites. If you are unlucky enough to be bitten, it can be painful but not dangerous. Mouse spiders, missulena bradleyi, are found on the outskirts of Melbourne, on the Mornington Peninsula and in the drier western areas of Victoria. They can also be aggressive but rarely bite. The bite is not known to be dangerous. Victorian funnel-web, mouse and trap-door spiders all live in burrows in the ground.

Funnel-webs burrow in sheltered sites under logs and rocks where they can find a cool and humid climate. Funnel-webs rush out of their burrow when potential prey, such as beetles, cockroaches, small lizards or snails, walk across silken trip-lines that the spider has placed around the outside of its burrow. They then return to their burrow to eat their meal.

 

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No, this is not true. Some female spiders do not eat their mates, however some species will eat the male, if they are smaller or food is scarce.

"We were surprised to find that such a simple characteristic such as how small males are relative to females has such a large effect on the frequency of sexual cannibalism," Wilder said.

Perhaps the most well-known example of spider-women eating spider-men is the black widow. But even that cannibalism case is overstated. For most of the many species of black widows, cannibalism is the exception, not the rule, according to Rod Crawford of the Burke Museum of Natural History & Culture at the University of Washington.

 

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It turns out that the notion is false on both counts. But a little clarification is needed.

According to entomologists at the University of California, Riverside, the term "daddy longlegs" is commonly used to refer to two distinct types of creatures: opilionids arachnids with pill-shape bodies and eight long legs that are actually not spiders, and pholcids, which have long legs and small bodies, and thus resemble opilionids, but which are true spiders.

Pholcids, or daddy long-legs spiders, are venomous predators, and although they never naturally bite people, their fangs are similar in structure to those of brown recluse spiders, and therefore can theoretically penetrate skin. For these reasons, "This is most probably the animal to which people refer when they tell the tale," the entomologists assert.

But is pholcids' venom extremely poisonous? Surprisingly, because they almost never bite, scientists have never bothered to conduct research to determine their venom's toxicity to humans . In 2004, the Discovery Channel show "Mythbusters" stepped in to fill this knowledge void. The team set out to coax a daddy longlegs spider into biting the arm of the show's co-host, Adam Savage.

 

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Sydney funnelweb spiders are not found in Victoria.

The two Victorian funnelweb spider species are relatives of the Sydney funnelweb spider. 

Funnelweb spiders are found around the east coast and the highlands of Australia (from Queensland to Tasmania) and small regions of South Australia. Most are found on the ground where they build burrows in moist, cool, sheltered areas, but some are tree-dwelling. They are regarded to be the most notorious of the Australian spiders due to their highly toxic and fast-acting venom. However, out of at least 40 species, only the male Sydney funnelweb spiders have been responsible for recorded deaths

Funnelweb spiders have a shiny black head and legs, and black to brown abdomen covered in fine hairs. The females are slightly larger (35 mm) than the males (30 mm).

The female produces a pillow-shaped silk egg sac, which she defends vigorously if disturbed. The spiderlings hatch about 3 weeks later, and stay with the mother for a few months. Funnelwebs reach maturity in about 2–4 years. The females live for 10 or more years, whereas the males die 6–9 months after maturity.

 

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The barking spider, sometimes called the whistling spider, is an Australian farantula. When disturbed, they produced a sound by rubbing their palps over their fangs. The largest are found in Queensland, and some have been found in north-west Victoria.

Barking Spiders produce their barking sound by rubbing rows of spines on their palaps against spines on their lower jaw. This noise is used to deter predators.

The deserts are prone to flash flooding and Barking Spiders live in burrows with leaky rooves. The hairs on their body trap air bubbles during flash floods and the air pocket prevents them from drowning.

Barking Spiders have brush feet with claw tufts and a film of oil produced from a special gland which gives them a suction cup ability to climb smooth vertical surfaces.

 

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