Date of Award

2016

Document Type

Thesis

Degree Name

Bachelors

Department

Natural Sciences

First Advisor

Gardiner, Jayne

Area of Concentration

Marine Biology

Abstract

This study examined the circadian rhythms of three captive nurse sharks (Ginglymostoma cirratum) under altered laboratory lighting conditions in order to better understand the daily rhythms of the species, to determine whether captive nurse sharks possess an endogenous circadian rhythm, and to evaluate the effects on activity of changing the location of photoreception on the body of the nurse shark. The sharks were exposed to three lighting regimens: 12L:12D, all dark, and all light to evaluate their activity patterns. Additionally, the eyes of each shark were covered with patches to determine if the pineal organ played a role in regulating the circadian rhythm. These captive animals were found to inconsistently exhibit both nocturnal behavior and endogenous circadian rhythms. It was found that changing the location of photoreception did not significantly alter the activity rhythms of the sharks. This study has implications for improvements to shark study and husbandry that better support the biological rhythms of the animal.

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