Meeting Abstract

119.3  Monday, Jan. 7  Autotomy and its effects on wolf spider foraging success STEFFENSON, M.M.*; FORMANOWICZ, D.R.; University of Texas at Arlington; University of Texas at Arlington mmsteff@uta.edu

Autotomy, or voluntary loss of various body parts, has been shown as an effective predator escape mechanism in many different taxa. The autotomy of a limb has the short-term benefit of escaping a predator. This defensive mechanism has associated costs: decreased mating success, diminished locomotive proficiency, and reduced territory size. Autotomy has also been hypothesized to negative effect foraging ability. However, few studies have actually tested this theory, particularly in spiders. The objectives of this study were to identify whether losing specific limbs through autotomy had different effects on foraging success. Mature Rabidosa rabida were captured from a creek bed in the Chiricahua mountains. R. santrita were separated into three groups: control (missing no legs), 1st leg (in which the 1st walking leg was autotomized), and 4th (in which the 4th walking leg was autotomized). The running speed of each individual was recorded both pre and post-autotomy. Each individual was introduced into an experimental chamber with five Pardosa valens (a local spider that is frequently preyed upon by R. santrita). Spiders were observed for 1 hour and the number of prey items captured was recorded every 15 minutes. Preliminary data analysis indicates that the running speed of spiders did not differ when any limb was removed. Additionally, the number of prey items consumed by the predator did not differ significantly, though a trend was observed of intact spiders consuming the highest proportion of available prey items, those missing a 1st walking leg consuming somewhat less, and individuals missing their 4th walking leg consuming the lowest proportion of available prey. Results indicate that while missing specific legs may affect a predator’s ability to forage, it does not do so significantly.