Electronic Theses and Dissertations

Identifier

699

Date

2012

Date of Award

7-24-2012

Document Type

Thesis

Degree Name

Master of Science

Major

Biology

Committee Chair

Bill A. Simco

Committee Member

Melvin L. Beck

Committee Member

Stanley E. Stevens

Abstract

The efficacy of the anesthetics Metomidate and MS-222 to modulate the cortisol response of channel catfish during a 10 min confinement stress was compared, in preparation for evaluating whether or not previous conditioning increases resistance to Edwardsiella ictaluri. Fingerlings anesthetized in Metomidate maintained baseline levels of cortisol concentrations throughout the study (P< 0.05), whereas levels increased correspondingly in fish anesthetized in MS-222and controls. Metomidateis useful for long periods of anesthetization, but MS-222 suppressed cortisolsecretion for only the first 5 min of sedation. During the conditioning study, the cortisol response among disturbed fingerlings decreased over time, indicating conditioning occurred. However, cortisolconcentrations of conditioned fingerlings increasedwhen subjected to a disease challenge, although their responsewas significantly lower compared to unconditioned controls.This indicates a possibleadvantage in conditioningfish, although differential susceptibility to a disease challenge has not yetbeen demonstrated.

Comments

Data is provided by the student.

Library Comment

dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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