Halloween Spiders

A bold jumping spider, Phidippus audax

In honor of Halloween I bring you spiders!  This little guy is a bold jumping spider who has been keeping me company in the lab for over a year now.  Bold jumping spiders are some of the largest and most recognizable jumpers I see around here, and some of my favorites.  These spiders are typically black with three white spots on the abdomen, although these markings may be yellow or orange in young spiders.  This particular spider started out with orange markings like a jack-o-lantern face which changed to white after the first molting in the lab.  A closer look will also reveal metallic blue or green chelicerae (mouthparts for grasping food, and the fangs in spiders).

A bold jumping spider, Phidippus audax

Jumping spiders belong to the family Salticidae, from the latin “salto” or “jump”.   As their name suggests they are excellent jumpers, able to leap more than ten times their body length to capture prey or avoid predators.  They do not spin webs, but use their silk as safety lines to anchor them when jumping, and also weave refuges, thick mats of silk to hide and shelter in.  The position and size of the eight eyes is often used as a character to distinguish spiders; the center front pair of eyes in salticids is enlarged, giving them excellent color vision and resolution as well as a somewhat more humanlike appearance than many other spiders.

A bold jumping spider confronting a pair of forceps.