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Long-Duration Carbon Dioxide Anesthesia of Fish Using Ultra Fine (Nano-Scale) Bubbles
Kenji Kugino1, Shizuka Tamaru1, Yuko Hisatomi2
1Division of Nutritional Science, Graduate School of Human Health Science, University of Nagasaki, Nagasaki, 851-2195, Japan.
Plos One
|April 22, 2016
Summary
Adding ultrafine oxygen-carrying bubbles to carbon dioxide (CO2) anesthesia for fish prevents death from hypoxemia. This method allows for safe, extended anesthesia in fish, enabling normal recovery.
Area of Science:
- Aquatic biology
- Fish physiology
- Anesthesia research
Background:
- Carbon dioxide (CO2) is commonly used for fish anesthesia.
- High concentrations of CO2 can cause lethal narcosis and hypoxemia in fish.
- Current methods lack safety for long-duration anesthesia.
Purpose of the Study:
- To investigate the efficacy of ultrafine oxygen-carrying bubbles with CO2 for fish anesthesia.
- To determine if this method ensures safe, long-duration anesthesia.
- To assess fish recovery after anesthesia.
Main Methods:
- Fish were exposed to dissolved CO2 in 20°C seawater to establish lethal effects.
- Ultrafine oxygen-carrying bubbles were concurrently supplied with dissolved CO2.
- Anesthesia duration and recovery times were monitored.
Main Results:
- CO2 alone caused rapid death in fish due to narcosis and hypoxemia within 30 minutes.
- Fish anesthetized with CO2 and oxygen bubbles remained sedated for 22 hours.
- All fish recovered normally within 2-3 hours after anesthesia cessation.
Conclusions:
- Ultrafine oxygen bubbles facilitate efficient oxygen diffusion across fish gills.
- The high oxygen levels in bubbles meet the metabolic demands of anesthetized fish.
- A novel method for safe, long-duration CO2 anesthesia in fish was demonstrated.
