Sac Spiders

Fast Facts

Classification

Family

Clubionidae

Suborder

Araneomorphae

Order

Araneae

Class

Arachnida

Phylum

Arthropoda

Kingdom

Animalia
Size Range

9 mm - 15 mm
Habitats

litter, peridomestic, under bark
Life history mode

terrestrial
Feeding Habits

arthropod-feeder, carnivorous, predator

Introduction

Sac spiders are found throughout Australia in forest and grassland habitats.

Identification

Slender Sac Spiders make small cylindrical or ovoid silk retreat sacs. They have slender bodies, large jaws and long, thin legs, with the males being especially slender. Most are shades of cream, brown or yellow, with a darker stripe along the upper abdomen. The jaws of the male spider are particularly enlarged.

The Stout Sac Spiders have stronger legs with robust, cylindrical bodies, reddish-brown to fawn in colour, often with chevron patterning on abdomen.

Habitat

Slender Sac Spiders are common hunters on foliage in bush and garden. They make their retreat sacs in folded leaves or grass blades, but sometimes enter houses, building their retreat sacs in wall and ceiling corners. Stout Sac Spiders may be found on house walls and fences but are most common under bark and in leaf litter. Their sheet-like sac retreats are often found under bark.

Distribution

Sac spiders are found throughout Australia in forest and grassland habitats.

Distribution data sourced from the Atlas of Living Australia

Life history cycle

Female sac spiders deposit their eggs inside the retreat sac and guard them from predators.

Danger to humans

Sac spider bites are not common and symptoms are usually minor. Symptoms include local pain and swelling. Symptoms of Slender Sac Spider (Cheiracanthum) bite may also include headache, nausea and local skin ulceration, though such reports are not common in Australia.

Seek medical attention if symptoms persist.