Date of Award


Document Type

Honors Thesis (Open Access)


Colby College. Biology Dept.


G. Russell Danner

Second Advisor

Paul G. Greenwood

Third Advisor

Catherine R. Bevier


Anesthesia plays a vital role in the maintenance of aquaculture species, where it is used to minimize stress during complex handling tasks such as transport, assessment, and harvesting. However, anesthetics have been shown to suppress the innate immune response, which could impact immunity and increase risk of infection. Tricaine methanesulfonate (MS-222) and 2-Phenoxyethanol (2-PE) represent two of the most commonly used anesthetics in aquaculture, with R-(+)-carvone, in the form of carvone-methyl salicylate (CMS) has recently been proposed as an alternative anesthetic for food fish. These three anesthetics were used to assess the influence of anesthetics on the immune system of zebrafish (Danio rerio), a model organism for immunological study. Respiratory burst assays of the zebrafish kidney leukocytes were used to determine the impact of these anesthetics on the immune response. All treatments showed a significantly decreased immunological response, with no statistical differences among treatments. These results indicate that CMS does not suppress the innate immune response any less than the anesthetics 2-PE or MS-222. Further investigation is needed to better understand the influence of CMS impact on a fish’s physiological response to confirm these findings.


Respiratory Burst Assay, Zebrafish, Tricaine, Carvone, 2-phenoxyethanol

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