Meeting Abstract

17.3  Saturday, Jan. 4 11:00  Kinematic and Behavioral Differences between Targeted and Untargeted Jumps in a Jumping Spider BRANDT, E.E.*; CHAN, N.S.; MILDER, M.J.; ELIAS, D.O.; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley eebrandt@berkeley.edu

Jumping has convergently evolved in many animal taxa. Although well-studied in insects such as grasshoppers, little attention has been paid to other arthropod groups such as spiders. Jumping spiders (Aranae, Salticidae) do not spin webs for prey capture, and instead use jumping as a primary means of locomotion (both escape from predators and prey capture). Previous work has shown that spiders have distinctive muscular morphology, incorporating hydraulic pressure into a unique jumping mechanism. However, jumping in jumping spiders has been understudied. In this study, we used Habronattus conjunctus, a desert-dwelling jumping spider, to investigate how jumping mechanisms differ between behavioral contexts. In particular we examined escape and targeted jumps. We found that spiders spent more time preparing for targeted jumps and attain relatively lower velocities. We also noted imprecise, often unpredictable aerial paths, and clumsy landings in escape jumps. We suggest that the increases in velocity and unpredictability are important to predator evasion and that a high degree of physical robustness has evolved in these spiders to allow them to withstand unwieldy landings. Finally, we found that spiders were unable to attain distances during escape untargeted jumps that they could easily attain in untargeted jump. We explore accuracy at different distances and speculate as to why distances on targeted jumps are so much shorter.