Wednesday, July 11, 2012
A big movie hit of this summer is “The Amazing Spider-Man: An IMAX 3D Experience” now playing at Pacific Science Center. Playing not too far away in the Insect Village are some very cool arachnids as well.
Not to upstage Peter Parker’s adventures, the Life Sciences Staff would like to share some spider fun facts:
What species live at PSC? Chilean Rose Tarantula, Black Widow, false black widow, Orb Weaver, and recently, a Wolf Spider*
and a Candy Stripe Spider**.
How old can they get? Pacific Science Center had a Rose Tarantula that live for thirteen years on site – and she was an adult when we got her. We thought this was impressive, because most spiders only live one or two years. But the oldest known tarantula lived to be twenty-eight years old.
Which species is the biggest? For many years it was considered the Goliath Bird Eating Spider, which weighs in at 170 grams (6 oz.). But the Giant Huntsman Spider, discovered in 2001 in Laos, has the widest leg span at 30 centimeters (12 inches). It is a lightly built spider; the Goliath Bird Eating Spider still holds the overall size record.
Which individual species spins the biggest web? The Darwin’s Bark Spider of Madagascar spins a web 25 meters wide (82 feet) across rivers. This orb-weaving spider probably builds in this way to capture mayfly-like insects that occur in large numbers at waterways. It gets its silk over the river by floating a single strand that is carried by the air column until it hits the trees on the far shore and is secured by them. The spider then uses this strand to maneuver while enlarging the web. The weight of the web is substantial, and the lead thread is thought to be one of the strongest naturally occurring materials – tougher than Kevlar!
What do they eat? Nearly all spiders are carnivorous. They have diverse methods of hunting – webs of various kinds, lassos with sticky ends, underwater silk diving bells, traps, running down prey, mimicking prey to lure it to them. Spiders do not have mouthparts to chew, so all of them consume their prey’s liquids, or liquefy their prey before eating. The exception, Bagheera kiplingi, a Costa Rican jumping spider was discovered in 2001, and independently confirmed in 2008. They primarily eat nubs on the leaves of acacia trees. Other spiders have been observed eating pollen and nectar, though all other species appear to just snack on those foods and primarily eat animals.
What are the different uses and kinds of silk? Spiders produce silk for many purposes: wrapping prey, swaddling egg cases, draglines to catch themselves when they fall, parachutes and balloons for floating on air currents, lining their homes to make them soft, building webs to catch prey, and even for parts of their mating rituals. Depending on its use, silk may be strong, soft, sticky, or elastic.
Some other facts:
Spiders have up to eight eyes. The number and arrangement is important in knowing what family a spider belongs to. Having multiple eyes allows spiders to see all around without having to move their head.
Tarantulas not only produce silk from spinnerets in their abdomens, but from the tips of their feet!
So why do you think that there are so many spiders in light fixtures?
*The Wolf Spider was found in Cari’s hallway.
** The Candy Stripe Spider was found on some Blackberry foliage that Terry and Martha were preparing to feed to the stick insects.
Posted by Terry at 4:54 PM