Impact of spectral composition on larval haddock, Melanogrammus aeglefinus L., growth and survival
G. Downing-2002
Aquaculture Research, 33(4): 251-260
Abstract:
In a small-scale culture experiment, larval haddock, Melanogrammus aeglefinus L., were raised under various combinations of light quality [blue (470 nm), green (530 nm) or full-spectrum white light] and light intensity [low (0.3-0.4 µmol s-1 m-2) or high (1.7-1.9 µmol s -1 m -2)], and in total darkness (both fed, and starved). Larval growth (0.9% day -1 in standard length; 2.4% day -1 in body area) was not significantly different between any combination of coloured light. At the time of total mortality in the starved treatment, survival was significantly reduced under low intensity, full-spectrum white light (13%) vs. all other coloured light treatments (68%). Larvae raised under both continuous dark treatments (fed and starved) exhibited morphological changes associated with irreversible starvation (point-of-no-return). Lack of a pronounced effect of light quality on larval haddock growth probably results from a combination of plasticity in early larval vision, and enhanced encounter rates between larvae and prey at the relatively high prey densities used in aquaculture.
(Department of Biology
and Centre for Coastal Studies and Aquaculture, University of New Brunswick,
Saint John Campus, Ganong Hall, PO Box 5050, Saint John, New Brunswick, E2L
4L5, Canada. E-mail: gav_dan@hotmail.com)