Honors Theses and Capstones

Date of Award

Spring 2016

Project Type

Senior Honors Thesis

College or School



Biological Sciences

Program or Major

Biomedical Sciences: MVS

Degree Name

Bachelor of Science


Previous studies have suggested that horseshoe crabs prefer warm water, suggesting that they may be able to detect changes in water temperature. The overall goal of this study was to test this hypothesis. Our specific objectives were to: 1) find out if horseshoe crabs can detect temperature changes; 2) determine the magnitude of temperature change they can detect, and; 3) determine whether their temperature receptors are located internally or externally. Animals were placed in a light-tight chamber that received a constant flow of cooled seawater. Their heart rates were continuously recorded and a change in heart rate following the addition of warmer water was used as an indicator that they sensed the change in temperature. The results showed that 50% of horseshoe crabs responded to a temperature change of 1°C, while 100% responded to a temperature change of 2.6°C. Over half of the horseshoe crabs also responded to a rate of temperature change of less than 1.5°C. Both of these results indicate that horseshoe crabs can, indeed, sense temperature changes. Also, the horseshoe crabs typically showed a response before their internal temperature changed, indicating that their temperature receptors are most likely located externally.