Ultraviolet light and semi‐recirculating systems in artificial incubation of noble crayfish (Astacus astacus) eggs: opportunities and limitations |
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| Authors: | Antonín Kouba Hamid Niksirat Iryna Kuklina Miloš Buřič Pavel Kozák |
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| Institution: | South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses and Research Institute of Fish Culture and Hydrobiology in Vodňany, Faculty of Fisheries and Protection of Waters, University of South Bohemia in ?eské Budějovice, , Vodňany, Czech Republic |
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| Abstract: | Development of artificial crayfish egg incubation is a milestone in intensive culture of crayfish as commercially important freshwater animals. This study evaluated experimental treatments combining continuous UV lighting, a non‐chemical antifungal treatment, with an initial formaldehyde bath for noble crayfish (Astacus astacus) eggs incubated in semi‐recirculating systems, which requires less than 1 per cent the amount of water necessary for conventional flow‐through systems. The one‐time administration of a pre‐incubation bath to reduce formaldehyde exposure was ineffective. Ultraviolet irradiation of recirculating water provided poor results (13.5% and 35.2% final survival rates to stage 2 juveniles) and led to deteriorating water quality. An inability of hatchlings to successfully moult and the occurrence of limb deformities was observed in UV‐treated groups, and juvenile mortality was found across all experimental treatments. |
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| Keywords: | astacid culture formaldehyde normal microflora oomycetes rearing water quality |
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