Sunday, 23 May 2010

More on Spiders

What's This? Spiders hanging themselves? No, not at all. We see these dangling from shrubbery, under tables, hoe handles in sheds and the like. These are the cast skins of moulting Huntsman (or if you want to be politically correct, Huntspersons) spiders. Spiders moult many times on their way to adulthood and many species continue to moult after becoming adult. Young spiders increase in size following each moult. In the case of adults and moulting, this is done to replace lost hairs and worn integument.

The spider selects and appropriate spot in the evening and drops a bit of webbing. It performs this necessary part of maturation in the evening because it is less likely that predators will see the dangling spider and the humidity is relatively higher affording some ease in getting out of the old skin. Then the transformation takes place at the end of the web. The entire exosklelton is shed over a period of s few hours. Then the spider crawls up the web, waits a bit and by the time morning rolls around, it is nearly ready to resume life. It spends the day undergoing changes that hardens up its integument and by evening it is ready to resume hunting. The process is initiated by hormones and moultng fluid helps to create a gap between the old skin and the new one that is forming beneath. This fluid is reabsorbed after moulting.

Adult ready to pounce.

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