Date Approved


Degree Type

Open Access Senior Honors Thesis

Department or School


First Advisor

Cara Shillington

Second Advisor

Kristin Judd

Third Advisor

Marianne Laporte


The functional and/or structural specialization of the left or right side of the brain (behavioral lateralization) has substantial impacts on the interactions an animal makes with other organisms and its surroundings. While this has been extensively shown throughout vertebrates, it has recently been demonstrated in various taxa of invertebrates. Despite this, its presence in arachnids, and specifically tarantulas, remains poorly understood. The purpose of this study was to determine whether behavioral lateralization is present in the juvenile tarantulas Pterinochilus murinus and Brachypelma albopilosum in response to prey odors. If behavioral lateralization was found, I aimed to detennine how it differed between species and at what level it evolved at (population vs individual). To do this, I analyzed the directional choice of each tarantula in a Tmaze under four different prey conditions: cricket in both arms, cricket in right arm, cricket in left arm, cricket absent. I found that a large proportion of the tarantulas from each species made no directional choice for the duration of each trial. Of the tarantulas that did make a directional choice across trials there was not a significant difference in the number of individuals to go left or right (p>0.5). The lack of significance was likely influenced low number of individuals that made a directional choice; however, each species showed a higher proportion of individuals turning towards the left for all of the conditions except for one. This is the first study to date examining the presence of behavioral lateralization in juvenile tarantulas.

Included in

Biology Commons