Complex Maze Test: Limulus polyphemus (American Horseshoe Crab)

Abstract: Investigations of learning in nonhuman animals focus predominantly on vertebrates, with invertebrate species behavior largely considered static and inflexible. However, recent studies on select invertebrate species suggest that assessments of learning are possible when ecologically relevant learning tasks and associated rewards are utilized. Horseshoe crabs (Limulus polyphemus) in particular are an invertebrate species that is highly utilized in laboratory work and biomedical research, yet little to no research on their capacity for learning or other cognitive functions has been undertaken to date. The goal of the present study was to develop an ecologically relevant maze learning task and establish the behavioral markers and criteria that indicate learning has occurred. Learning and being able to retrieve acquired information is often crucial for an animal to navigate their environment effectively and efficiently. Evaluating learning in horseshoe crabs through the proposed maze task could lead to improved population surveying methods. Additionally, documenting behavioral plasticity could broaden the attention of the Institutional Animal Care and Use Committee (IACUC) and other standard laboratory and in-situ protections, as well as establishing a foundation towards horseshoe crab, and other invertebrate, learning and cognition-based research.

For more information email: dkdavido@eckerd.edu, mrlouren@eckerd.edu