Chapter 7

Spiders, their Venoms, and a Bit More

Olen R. Brown

Abstract

Spiders rarely engender neutral feelings in people; many fear them and some find them repugnant. There are a few examples in literature of spiders portrayed in a positive light and they are whimsically described in children’s verses and stories. Scientifically, spiders are interesting biologically for their behavior, especially their webs. Spider silk from which webs are made is noted for its high strength, which exceeds (on a weight-comparison basis) steel and man-made fibers, and its elasticity which allows webs to catch flying insects with impacts of a thousand watts of power. Spider venoms have a wide variety of chemical structures and biological activities. Some, including venom of the black widow spider, have neurotoxic components and the complete venom of this spider is similar in toxicity to that of rattlesnake venom. The Brazilian wandering spider and the Australian funnel web spider vie for the title of most venomous spider. The brown recluse is feared over large regions of the central United States because of the large necrotic wound that can result from their bite and their reclusive nature coupled with their tendency to occupy human residences. The tarantula is widespread around the world and has unusual ability to shoot poisonous hairs from its body in addition to a venomous bite which, fortunately, is not usually medically serious for humans. Venoms from many spider species are useful for scientific studies because some interfere with the mechanisms used for communication between and within cells for various physiologically essential functions. Spider venoms are being investigated as tools for studying nerve cell functions including impulse transmission. They also are being explored as pain killers and used as tools in the search for causation and cures for several devastating neurological conditions.

Total Pages: 168-201 (34)

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