Date of Award


Document Type


Degree Name

Master of Science (MS)


College of Science and Mathematics


Marine Biology and Coastal Sciences

Thesis Sponsor/Dissertation Chair/Project Chair

Scott Kight

Committee Member

Paul Bologna

Committee Member

Sandra Adams


Trail-following behavior is exhibited by many species ranging from insects to gastropods. In gastropods, this behavior serves many functions such as the facilitation of movement, homing, mate and conspecific location, organization, aggregation, and protection. Kin recognition is also a behavior that is exhibited by a wide variety of species including both vertebrate and invertebrate animals. Kin recognition serves many functions including social interactions and status, discrimination, which can lead to outcrossing, and cooperative behaviors that can increase the likelihood of survival. Familiarity with individuals may also contribute to survival through protection and enhanced cooperation. Kin recognition can involve familiarity in conjunction with the detection of genetically-mediated cues or markers, and trail-following mechanisms may be linked to the chemical components of the trail itself. Experiments were conducted to determine whether kinship and/or familiarity influence the trail-following behavior of juvenile Physa acuta, a freshwater snail. The degree of trail-following was determined by tracing the trails of marker and tracker snails and by using the lengths of the trails and lines of overlap to calculate a coincidence index. The total length of the tracker trail and marker trail were analyzed to detect differences in marker and tracker trail lengths. There was no significant effect of kinship and familiarity on coincidence index and trail length. There was a pattern for trackers to follow trails of unfamiliar individuals and a pattern whereby tracker snails left longer trails when exposed to the trails of familiar marker snails. Possible benefits for following the trail of an unfamiliar individual may include colonizing a new hospitable environment with other conspecifics or leading the snail away from an inhospitable region. Increase in crawl distance for tracker snails may have been motivated by exploration of new environments, as the presence of a familiar individual would be associated with familiar locations that have already been explored. This study provides insight into the possible role of familiarity in trail-following and locomotive behavior in Physa acuta.