Silver-plated spiders

Jul. 2,1999. M.Sekine

A Cyclosa argenteoalba

At the left, can be seen the picture of a female Cyclosa argenteoalba. What a beautiful spider! These spiders' abdomens are silver with black markings, and look like they are plated with silver reflecting the sunlight in a blue sky. They are, as it were, silver-plated spiders.
Most spiders take up their position on the hub of the orbweb upside down, but this species is upright. Why? Or phrased another way, 'why do conventional spiders take up their position upside down?' What a wonder! Spiders are splendid!