The+Hunting+Spiders+-+The+Sac+Spiders

=The Hunting Spiders - Part 2 =

__SAC SPIDERS (Clubionidae) __

Kingdom: Animalia Phylum: Arthropoda Class: Arachnida Order: Araneae Infraorder: Araneomorphae Family: Clubionidae

Fig. 1: Front-view of a Sac Spider.

The family name sac spider is not to be confused with the other sac spider families, such as the anyphaenid sac spider (Anyphaenidae), the tengellid sac spider (Tengellidae), the zorocratid sac spider (Zorocratidae), etc. Notice that these sac spider families are indicated by their specific Latin name. The Clubionidae is often referred to as "sac spiders" on its own (Tree of Life Web Project).

The sac spider family consists of 537 species and it has a wide geographic range (Roddy 1966). Sac spiders may not be web spinners, but they tend to build silk sacs to either protect their eggs or act as a hideaway when they do not hunt (Suter et al. 2011). These sacs are impressively designed architectural structures, with several purposes (Suter et al. 2011). Their sacs are often constructed with bits of plants, such as grass blades, cattails, and leaves (Suter et al. 2011). Sac spiders are nocturnal hunters, meaning they hunt for their prey at night (Pollard 1984). The sac spiders inhabit either open spaces on the ground or in the leaves and branches of trees (Suter et al. 2011). They tuck their sac refuges away in hidden spaces such as leaves, stones, or logs during the day when they do not search for prey (Suter et al. 2011). Female sac spiders will keep their eggs in their sacs, which tend to be larger than the sacs they inhabit during the day (Suter et al. 2011). Female sac spiders display the unique behavior of “egg-guarding” in which they will guard their eggs against predators (Pollard 1984).

Fig. 2: Spider's egg sac on the stalks of a plant.

Sac spiders’ length ranges from 2.5 to 12 mm long (Roddy 1966). They have eight eyes that are similarly sized and their fourth pair of legs is shorter than their first pair of legs (Roddy 1966). Sac spiders can be noted for the elongated dark mark on the middle of their abdomens (Roddy 1966).

The most common sac spiders found in Vermont are the Yellow Sac Spiders and the Leaf-curling Sac Spiders (Platnick and Solomon 2013).

Fig. 3: Aerial view of a Sac Spider.

Created by D. Bartolanzo

For information on their impacts on humans, go to this website!

[]

References:

1. Platnick, N. I., and Solomon, P. J. "The World Spider Catalog." The World Spider Catalog. American Museum of Natural History, 17 May 2013. Web. 11 Nov. 2013. .

2. Pollard, D. S. 1984. Egg guarding by //Clubiona camridgei// (Araneae, Clubionidae) against conspecific predators. The Journal of Arachnology. 11: 323-326.

<span style="font-family: Verdana,Geneva,sans-serif;">3. Roddy, L. R. 1966. New species, records, of clubionid spiders. Transactions of the American Microscopical Society. 85: 399-407.

<span style="font-family: Verdana,Geneva,sans-serif;">4. Suter, R. B., Miller, P. R., and Gail, E. S. 2011. Egg capsule architecture and siting in a leaf-curling sac spider, //Clubiona riparia// (Araneae: Clubionidae). The Journal of Arachnology. 39: 76-83.

<span style="font-family: Verdana,Geneva,sans-serif;">5. Tree of Life Web Project. 2006. Clubionidae. Version 25 March 2006 (temporary). [] in The Tree of Life Web Project, []

Images:

<span style="font-family: Verdana,Geneva,sans-serif;">Figure 1: Karwath, Andre (Photographer). (May 19, 2007). [Web Photo] Retrieved from

<span style="font-family: Verdana,Geneva,sans-serif;">Figure 2: ceridwen (Photographer). (August 31, 2007). Geograph.org [Web Photo] Retrieved from

<span style="font-family: Verdana,Geneva,sans-serif;">Figure 3: Maxwell, John R. (Photographer). (April 20, 2010). BugGuide.net [Web Photo] Retrieved from []