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Published on: September 16, 2018
The use of bronopol to control fungal infection in rainbow trout eggs
Heisuke Oono1, Kishio Hatai, Masayuki Miura
1Division of Fish Diseases, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino, Tokyo 180-8602, Japan.
Abstract:
We evaluated bronopol as a practical alternative anti-fungal agent to malachite green for use in hatcheries. Repeated exposure everyday, just after fertilization to the stage of eggs showing eye development to 50 mg/L and 100 mg/L bronopol for 30 min showed an efficacy comparable to 0 mg/L (control) for the inhibition of fungal infection in rainbow trout (Oncorhynchus mykiss) eggs. The 100 mg/L bronopol treatment groups showed a control of fungal infection up to the stage of eye development in eggs. Significant differences in terms of the number of eggs showing eye development were seen between 0 mg/L and treatment at 50 and 100 mg/L bronopol.
Insights
Bronopol effectively inhibits fungal infections in rainbow trout eggs, offering a practical alternative to malachite green in hatcheries. Treatments demonstrated comparable efficacy to controls, with significant improvements in egg development observed.
Area of Science:
- Aquaculture
- Fish Health
- Mycology
Background:
- Malachite green, a common antifungal, faces regulatory scrutiny.
- Fungal infections pose a significant threat to fish egg viability in hatcheries.
- There is a need for effective and safe antifungal alternatives.
Purpose of the Study:
- To evaluate bronopol as a potential replacement for malachite green.
- To assess the efficacy of bronopol in preventing fungal infections in rainbow trout eggs.
- To determine optimal concentrations of bronopol for hatchery use.
Main Methods:
- Rainbow trout eggs were exposed to varying concentrations of bronopol (50 mg/L and 100 mg/L) daily.
- Exposure duration was 30 minutes, from fertilization to eye development stage.
- Fungal infection inhibition and egg development were monitored and compared to control groups.
Main Results:
- Bronopol demonstrated efficacy in inhibiting fungal infections in rainbow trout eggs.
- The 100 mg/L bronopol treatment effectively controlled fungal growth up to eye development.
- Significant increases in the number of eggs reaching eye development were observed in bronopol-treated groups compared to controls.
Conclusions:
- Bronopol is a viable alternative antifungal agent for rainbow trout hatcheries.
- Bronopol effectively controls fungal infections in fish eggs.
- Further research may optimize bronopol application for improved aquaculture biosecurity.
