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- HOW TO ANAESTHETISE A FISH -
Anaesthetics are widely used, particularly in the aquaculture industry, to immobilise or relax a fish. This is essential in reducing stress, and allows for control during a vast range of procedures including medical tagging, weighing, measuring, vaccinating and surgery.
Anaesthetics are most commonly administered through tank water. It is therefore important to administer the minimal dosage required for the specific tank. It is also essential that fish are fasted for 12-24 hours prior to the delivery of the anaesthetic.
Once fish are anaesthetised it is essential that all other water parameters (see How to Water Test) are monitored closely during this period. Fish should also be monitored for 24 hours following anaesthesia.
Once fish are anaesthetised it is essential that all other water parameters (see How to Water Test) are monitored closely during this period. Fish should also be monitored for 24 hours following anaesthesia.
Commonly used anaesthetics include:
- Tricaine Methane Sulphonate -
TMS powder is a widely used anaesthetic. It is most effective in salmonids (salmon, trout, whitefish). Fish should not be harvested within 21 days of anaesthetic dosage. Particular attention to water pH is necessary when using this anaesthetic.
Dosage: Moderate sedation 80-100mg/L
Lethal Dosage: 300-400mg/L
- Benzocaine -
Particular attention to water pH is necessary when using this anaesthetic.
Dosage: 60mg/L
Lethal Dosage: 100mg/L
- Tricaine Methane Sulphonate -
TMS powder is a widely used anaesthetic. It is most effective in salmonids (salmon, trout, whitefish). Fish should not be harvested within 21 days of anaesthetic dosage. Particular attention to water pH is necessary when using this anaesthetic.
Dosage: Moderate sedation 80-100mg/L
Lethal Dosage: 300-400mg/L
- Benzocaine -
Particular attention to water pH is necessary when using this anaesthetic.
Dosage: 60mg/L
Lethal Dosage: 100mg/L
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[9] Youtube (2014) Recognising the stages of Anaesthesia and Anaesthetic depth in Zebrafish
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Many anaesthetics can also be used to euthanase fish when in different concentrations. Benzocaine is less commonly used for euthanasia due to the minor difference in concentrations causing sedation and death.
[7] NOVA Science (2014) [8] Griffiths, D. (2014) |