A spider is a small, eight legged invertebrate closely related to scorpions, mites and ticks. They are an ancient order with fossils dating back over 400 million years. All spiders are divided into two body parts; the head area or cephalothorax onto which the legs are connected and the abdomen. They have no jaws so all of their food must be in a liquid form. All spiders have fangs and most possess poison glands which are used in capturing other animals for food. There are two basic types of fang. The most primitive strike vertically downwards such as seen in funnel-webs and tarantulas. The more advanced form close towards each other like a pair of pincers. Huntsman spiders and red-backs are examples of the latter. All spiders can also produce various types of silk, which is used to provide shelter, catch prey and protect eggs and baby spiders.
How is Antivenom Produced?
One of the important functions of the Australian Reptile Park, along with education and tourism, is the collection of venom from deadly species of snakes and spiders. The venom is used by the Commonwealth Serum Laboratories - better known as CSL Limited, to manufacture the only Australian antivenoms that save human snakebite spiderbite victims. The Reptile Park is the sole supplier of the venoms required by CSL Limited in the production of antivenoms for terrestrial snakes (not sea snakes) and funnel-web spiders. To keep up the supply of venoms, highly trained staff of the Australian Reptile Park regularly 'milk' more than 300 snakes and 500 spiders that are included in the program.
A simplified explanation of how the snake antivenoms are produced, is that extremely small amounts of say, tiger snake venom are injected into huge Percheron horses on a regular basis over a long period of time. The amounts are so small that the horses are not affected except that produces antibodies to counteract the foreign substance in its system. After some 10-12 months of this immunological 'conditioning', a small proportion of each horse's blood is removed and the plasma is extracted. This plasma contains the antibodies which, when injected into a snake bite victim, will neutralize snake venom. In the case of funnel-web spider antivenom, rabbits are used instead of horses. These animals suffer no ill-effects and are used repeatedly to help save human lives in this fashion. Some of the horses have been carrying out this essential service to Australians for many years. The funnel-web spider program at the Park depends largely upon the provision of male specimens from the area within 150 km of Sydney.