Masters Theses

Date of Award

8-2000

Degree Type

Thesis

Degree Name

Master of Science

Major

Wildlife and Fisheries Science

Major Professor

J. Larry Wilson

Committee Members

Richard Strange, Tom Hill

Abstract

The demand for a safe, economical, easy-to-use anesthetic is becoming increasingly necessary to keep up with the demands of aquaculture. Over the past five years, clove oil has become an often-used anesthetic in fisheries. It is inexpensive, safe to use, and has no stringent regulations imposed on it.

We examined the use of clove oil as a stress reducer and as an anesthetic in yearling rainbow trout. When exposed to a 25 mg/L dosage of clove oil, trout lost equilibrium and became anesthetized within approximately one minute (range of 45-90 seconds) after exposure. They recovered and were swimming normally within 5-10 minutes after being placed in freshwater.

When blood cortisol levels (an indicator of stress) were measured in trout exposed to an anesthetizing dose of clove oil for a 60-minute period, there was a significant increase in cortisol concentration (166.2 ng/mL) after 10 minutes in the anesthetizing solution. Cortisol concentrations then decrease to levels lower than that of Time 0 fish after 30,40, 50, and 60 minutes in the clove oil solution.

The mean cortisol concentration level (163.5 ng/mL) in fish from the "standard" handling practice used in culture operations was significantly higher after 15 minutes in clove oil than the mean cortisol concentration level (93.1 ng/mL) of fish with no exposure to clove oil (control), and to the mean cortisol level (65.7 ng/mL) of undisturbed fish (sneak) being exposed to clove oil.

Clove oil is readily available, easy to use, and safe to humans. Its advantages are that it induces a quick induction time Eind an adequate recovery time in rainbow trout. It is inexpensive when compared to MS-222 and has no FDA regulations. One potential disadvantage is that at concentrations of 25 mg/L clove oil stimulates a cortisol stress response. There is relatively little information on the effects of clove oil on the physiology of fish. The examination of clove oil as an inducer of stress should be investigated more closely.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS