maengmoom kradoht (แมงมุมกระโดด)
spider’. Generic name for any spider in the family
Salticidae, with more than 500 described genera
and about 5,000 described species, the world's largest family of
spiders, accounting for about 13% of all species, with most of them
found in tropical forests. Its tiny members are in English, similar as in
Thai, commonly referred to as
jumping spiders, as they are capable of jumping,
often several times the length of their body.
Unlike grasshoppers that have strong muscular
legs, jumping spiders are capable of leaping forward by altering
their blood (bodily fluid) pressure within their limbs, using a
well-developed internal hydraulic system.
Before they jump over
heights, they secure themselves with a thin silken thread, in case
they should fall. Jumping spiders are known for their
hairy legs, superior eyesight,
curiosity and inquisitiveness. They have eight eyes and the largest
ones, the principal eyes in the front of the head are very
specialized and are very good at seeing spatial detail. Jumping
spiders do not posses eyeballs, but have
mushroom-shaped eyes, that
a fixed lens on the outside and a
tiny retina at the back of a long tube on the inside, which the spider is able to
move due to
muscles that surround these
allows the spider to look from one
side to the other while sitting still and make for a perfect hunting
tool when ambushing prey without any outer movement. Mostly carnivorous, they are diurnal,
active hunters and usually stalk their prey, though there are some
species that also eat nectar and pollen, and at least one species
that lives on plant matter.
See also WILDLIFE PICTURES.