The effect of light intensity and spectrum on the incidence of first feeding by larval haddock |
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Authors: | G Downing M K Litvak |
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Institution: | Department of Biology and Centre for Coastal Studies and Aquaculture, University of New Brunswick (Saint John), Ganong Hall, P.O. Box 5050, Saint John, New Brunswick, E2L 4L5, Canada |
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Abstract: | Under full–spectrum white light, feeding success of haddock Melanogrammus aeglefinus first feeding larvae, as measured both by proportion of larvae feeding and mean prey consumed, peaked at 1·7-18 μmol s-1 m-2. Feeding was significantly reduced at lower and higher intensities. A similar result was observed for larvae feeding under blue (470 nm) light, with significantly greater feeding success at intermediate light intensity (1·8 μmol s-1 m-2). When different light qualities were compared, larvae had significantly greater feeding success when exposed to blue (470 nm) light than either full-spectrum white or green (530 nm) light. Haddock larvae were capable of prey capture under all light treatments tested, indicating a necessary degree of adaptive flexibility in feeding response. The results are consistent with predisposition of haddock larvae to optimal feeding in a visual environment comparable with open ocean nursery grounds. Information on the impact of light on haddock first feeding can be incorporated into models of larval growth, survival, year-class strength and recruitment, and assist in developing husbandry protocols to maximize larval survival in aquaculture. |
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Keywords: | first feeding haddock Melanogrammus aeglefinus larva light intensity light quality |
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