The effect of
light intensity and spectrum on the incidence of first feeding by larval
haddock
G. Downing, M. K. Litvak-2001
Journal of Fish Biology, 59(6): 1566-1578
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 1·7-18µmols-1m-2.
Feeding was significantly reduced at lower and higher
intensities. A similar result was observed for larvae
feeding under blue (470nm) light, with significantly
greater feeding success at intermediate light intensity
(1·8µmol s-1m-2). When different light qualities
were compared, larvae had significantly greater
feeding success when exposed to blue (470nm) light
than either full-spectrum white or green (530nm)
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.
(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,
Tel.: +1 506 648 5508; fax: +1 506 648 5811; email:gav-dan@hotmail.com)