Efficacy of clove oil and ethanol against Saprolegnia sp. and usability as antifungal agents during incubation of rainbow trout Oncorhynchus mykiss (Walbaum) eggs |
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| Authors: | Petri Hoskonen Jouni Heikkinen Päivi Eskelinen Juhani Pirhonen |
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| Affiliation: | 1. Department of Biological and Environmental Science, University of Jyv?skyl?, Jyv?skyl?, Finland;2. Department of Biosciences, University of Eastern Finland, Kuopio, Finland;3. Finnish Game and Fisheries Research Institute, Jyv?skyl?, Finland |
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| Abstract: | Inhibitory concentrations of clove oil and ethanol against growth of Saprolegnia sp. hyphae were screened by a modification of the hemp (Cannabis sativa L.) seed MicroPlate (HeMP) method and their usability as antifungal agents during incubation of rainbow trout Oncorhynchus mykiss eggs was tested. In vitro experiment showed that in continuous static exposure, clove oil at 100 mg L?1 significantly inhibited the growth of Saprolegnia, whereas in bath exposures, clove oil at 500 mg L?1 had no significant effect at any exposure time tested (15, 60 and 240 min), but clove oil at 10 000 mg L?1 significantly inhibited growth at all exposure times. Clove oil and ethanol treatments had no visible effects on the onset or spread of the fungus during incubation of rainbow trout eggs. Clove oil at 1000 mg L?1 resulted in 95–100% mortality before the eyed stage was reached. Sublethal concentrations of clove oil and ethanol had no effects on the development rate of the embryo or growth and yolk utilization efficiency after hatching. This study suggests that clove oil and ethanol may not be options in controlling aquatic fungi infestations during incubation of rainbow trout eggs. |
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| Keywords: | water mould aquatic fungi eugenol fungicide hemp seed yolk efficiency |
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